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* mysql: (mysql). MySQL documentation.
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The information contained herein is subject to change without notice
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You may create a printed copy of this documentation solely for your own
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however that the documentation is disseminated together with the
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another publication, requires the prior written consent from an
authorized representative of Oracle. Oracle and/or its affiliates
reserve any and all rights to this documentation not expressly granted
above.

For more information on the terms of this license, for details on how
the MySQL documentation is built and produced, or if you are interested
in doing a translation, please visit MySQL Contact & Questions
(http://dev.mysql.com/contact/).

For additional licensing information, including licenses for
third-party libraries used by MySQL products, see *Note Top::.

If you want help with using MySQL, please visit either the MySQL Forums
(http://forums.mysql.com) or MySQL Mailing Lists
(http://lists.mysql.com) where you can discuss your issues with other
MySQL users.

For additional documentation on MySQL products, including translations
of the documentation into other languages, and downloadable versions in
variety of formats, including HTML and PDF formats, see the MySQL
Documentation Library (http://dev.mysql.com/doc).

* Menu:

* preface:: Preface and Notes
* introduction:: General Information
* installing:: Installing and Upgrading MySQL
* tutorial:: Tutorial
* programs:: MySQL Programs
* server-administration:: MySQL Server Administration
* backup-and-recovery:: Backup and Recovery
* optimization:: Optimization
* language-structure:: Language Structure
* internationalization-localization:: Internationalization and Localization
* data-types:: Data Types
* functions:: Functions and Operators
* sql-syntax:: SQL Statement Syntax
* storage-engines:: Storage Engines
* ha-overview:: High Availability and Scalability
* mem-introduction:: MySQL Enterprise Monitor
* replication:: Replication
* mysql-cluster:: MySQL Cluster
* stored-programs-views:: Stored Programs and Views
* information-schema:: `INFORMATION_SCHEMA' Tables
* connectors-apis:: Connectors and APIs
* extending-mysql:: Extending MySQL
* licenses-third-party:: Licenses for Third-Party Components
* faqs:: MySQL 5.0 Frequently Asked Questions
* error-handling:: Errors, Error Codes, and Common Problems
* news:: MySQL Change History
* restrictions:: Restrictions and Limits

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1 Preface and Notes
*******************

This is the Reference Manual for the MySQL Database System, version
5.0, through release 5.0.93. Differences between minor versions of
MySQL 5.0 are noted in the present text with reference to release
numbers (5.0.X). For license information, see the legal notice. This
product may contain third-party code. For license information on
third-party code, see *Note licenses-third-party::.

This manual is not intended for use with older versions of the MySQL
software due to the many functional and other differences between MySQL
5.0 and previous versions. If you are using an earlier release of the
MySQL software, please refer to the appropriate manual. For example,
`MySQL 3.23, 4.0, 4.1 Reference Manual'
(http://dev.mysql.com/doc/refman/4.1/en/), covers the 4.1 series of
MySQL software releases.

If you are using MySQL 5.1, please refer to the `MySQL 5.1 Reference
Manual' (http://dev.mysql.com/doc/refman/5.1/en/).

File: manual.info, Node: introduction, Next: installing, Prev: preface, Up: Top

2 General Information
*********************

* Menu:

* manual-info:: About This Manual
* manual-conventions:: Typographical and Syntax Conventions
* what-is:: Overview of the MySQL Database Management System
* development-history:: MySQL Development History
* mysql-nutshell:: What Is New in MySQL 5.0
* information-sources:: MySQL Information Sources
* bug-reports:: How to Report Bugs or Problems
* compatibility:: MySQL Standards Compliance
* credits:: Credits

End of Product Lifecycle

Active development and support for MySQL Database Server version 5.0
has ended. However, there is still extended support available. For
details, see http://www.mysql.com/about/legal/lifecycle/#calendar.
According to the MySQL Lifecycle Policy (see
http://www.mysql.com/about/legal/lifecycle/#policy), only Security and
Severity Level 1 issues will still be fixed for MySQL 5.0. Please
consider upgrading to a recent version.

The MySQL(tm) software delivers a very fast, multi-threaded,
multi-user, and robust SQL (Structured Query Language) database server.
MySQL Server is intended for mission-critical, heavy-load production
systems as well as for embedding into mass-deployed software. Oracle is
a registered trademark of Oracle Corporation and/or its affiliates.
MySQL is a trademark of Oracle Corporation and/or its affiliates, and
shall not be used by Customer without Oracle's express written
authorization. Other names may be trademarks of their respective owners.

The MySQL software is Dual Licensed. Users can choose to use the MySQL
software as an Open Source product under the terms of the GNU General
Public License (`http://www.fsf.org/licenses/') or can purchase a
standard commercial license from Oracle. See
http://www.mysql.com/company/legal/licensing/ for more information on
our licensing policies.

The following list describes some sections of particular interest in
this manual:

* For a discussion about the capabilities of the MySQL Database
Server, see *Note features::.

* For development history, see *Note development-history::.

* For installation instructions, see *Note installing::. For
information about upgrading MySQL, see *Note upgrading::, and the
change notes at *Note news::.

* For a tutorial introduction to the MySQL Database Server, see
*Note tutorial::.

* For information about configuring and administering MySQL Server,
see *Note server-administration::.

* For information about setting up replication servers, see *Note
replication::.

* For answers to a number of questions that are often asked
concerning the MySQL Database Server and its capabilities, see
*Note faqs::.

* For a list of currently known bugs and misfeatures, see *Note
bugs::.

* For a list of all the contributors to this project, see *Note
credits::.

* For a history of new features and bugfixes, see *Note news::.

* For tips on porting the MySQL Database Software to new
architectures or operating systems, see MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* For benchmarking information, see the `sql-bench' benchmarking
directory in your MySQL distribution.

To report errors (often called `bugs'), please use the instructions at
*Note bug-reports::.

If you have found a sensitive security bug in MySQL Server, please let
us know immediately by sending an email message to <security@mysql.com>.

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2.1 About This Manual
=====================

If you are using MySQL 5.1, please refer to the `MySQL 5.1 Reference
Manual' (http://dev.mysql.com/doc/refman/5.1/en/).

Because this manual serves as a reference, it does not provide general
instruction on SQL or relational database concepts. It also does not
teach you how to use your operating system or command-line interpreter.

The MySQL Database Software is under constant development, and the
Reference Manual is updated frequently as well. The most recent version
of the manual is available online in searchable form at
`http://dev.mysql.com/doc/'. Other formats also are available there,
including HTML, PDF, and Windows CHM versions.

The Reference Manual source files are written in DocBook XML format.
The HTML version and other formats are produced automatically,
primarily using the DocBook XSL stylesheets. For information about
DocBook, see `http://docbook.org/'

If you have questions about using MySQL, you can ask them using our
mailing lists or forums. See *Note mailing-lists::, and *Note forums::.
If you have suggestions concerning additions or corrections to the
manual itself, please send them to the
http://www.mysql.com/company/contact/.

This manual was originally written by David Axmark and Michael `Monty'
Widenius. It is maintained by the MySQL Documentation Team, consisting
of Paul DuBois, Stefan Hinz, Jon Stephens, Tony Bedford, and John
Russell.

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2.2 Typographical and Syntax Conventions
========================================

This manual uses certain typographical conventions:

* `Text in this style' is used for SQL statements; database, table,
and column names; program listings and source code; and
environment variables. Example: `To reload the grant tables, use
the *Note `FLUSH PRIVILEGES': flush. statement.'

* Text in this style indicates input that you type in examples.

* `Text in this style' indicates the names of executable programs
and scripts, examples being *Note `mysql': mysql. (the MySQL
command line client program) and *Note `mysqld': mysqld. (the
MySQL server executable).

* TEXT IN THIS STYLE is used for variable input for which you should
substitute a value of your own choosing.

* _Text in this style_ is used for emphasis.

* *Text in this style* is used in table headings and to convey
especially strong emphasis.

* `Text in this style' is used to indicate a program option that
affects how the program is executed, or that supplies information
that is needed for the program to function in a certain way.
_Example_: `The `--host' option (short form `-h') tells the *Note
`mysql': mysql. client program the hostname or IP address of the
MySQL server that it should connect to'.

* File names and directory names are written like this: `The global
`my.cnf' file is located in the `/etc' directory.'

* Character sequences are written like this: `To specify a wildcard,
use the ``%'' character.'

When commands are shown that are meant to be executed from within a
particular program, the prompt shown preceding the command indicates
which command to use. For example, `shell>' indicates a command that
you execute from your login shell, `root-shell>' is similar but should
be executed as `root', and `mysql>' indicates a statement that you
execute from the *Note `mysql': mysql. client program:

shell> type a shell command here
root-shell> type a shell command as ROOT here
mysql> type a mysql statement here

In some areas different systems may be distinguished from each other to
show that commands should be executed in two different environments.
For example, while working with replication the commands might be
prefixed with `master' and `slave':

master> type a mysql command on the replication master here
slave> type a mysql command on the replication slave here

The `shell' is your command interpreter. On Unix, this is typically a
program such as `sh', `csh', or `bash'. On Windows, the equivalent
program is `command.com' or `cmd.exe', typically run in a console
window.

When you enter a command or statement shown in an example, do not type
the prompt shown in the example.

Database, table, and column names must often be substituted into
statements. To indicate that such substitution is necessary, this
manual uses DB_NAME, TBL_NAME, and COL_NAME. For example, you might see
a statement like this:

mysql> SELECT COL_NAME FROM DB_NAME.TBL_NAME;

This means that if you were to enter a similar statement, you would
supply your own database, table, and column names, perhaps like this:

mysql> SELECT author_name FROM biblio_db.author_list;

SQL keywords are not case sensitive and may be written in any
lettercase. This manual uses uppercase.

In syntax descriptions, square brackets (``['' and ``]'') indicate
optional words or clauses. For example, in the following statement, `IF
EXISTS' is optional:

DROP TABLE [IF EXISTS] TBL_NAME

When a syntax element consists of a number of alternatives, the
alternatives are separated by vertical bars (``|''). When one member
from a set of choices _may_ be chosen, the alternatives are listed
within square brackets (``['' and ``]''):

TRIM([[BOTH | LEADING | TRAILING] [REMSTR] FROM] STR)

When one member from a set of choices _must_ be chosen, the
alternatives are listed within braces (``{'' and ``}''):

{DESCRIBE | DESC} TBL_NAME [COL_NAME | WILD]

An ellipsis (`...') indicates the omission of a section of a statement,
typically to provide a shorter version of more complex syntax. For
example, *Note `SELECT ... INTO OUTFILE': select. is shorthand for the
form of *Note `SELECT': select. statement that has an `INTO OUTFILE'
clause following other parts of the statement.

An ellipsis can also indicate that the preceding syntax element of a
statement may be repeated. In the following example, multiple
RESET_OPTION values may be given, with each of those after the first
preceded by commas:

RESET RESET_OPTION [,RESET_OPTION] ...

Commands for setting shell variables are shown using Bourne shell
syntax. For example, the sequence to set the `CC' environment variable
and run the `configure' command looks like this in Bourne shell syntax:

shell> CC=gcc ./configure

If you are using `csh' or `tcsh', you must issue commands somewhat
differently:

shell> setenv CC gcc
shell> ./configure

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2.3 Overview of the MySQL Database Management System
====================================================

* Menu:

* what-is-mysql:: What is MySQL?
* history:: History of MySQL
* features:: The Main Features of MySQL

File: manual.info, Node: what-is-mysql, Next: history, Prev: what-is, Up: what-is

2.3.1 What is MySQL?
--------------------

MySQL, the most popular Open Source SQL database management system, is
developed, distributed, and supported by Oracle Corporation.

The MySQL Web site (http://www.mysql.com/) provides the latest
information about MySQL software.

* MySQL is a database management system.

A database is a structured collection of data. It may be anything
from a simple shopping list to a picture gallery or the vast
amounts of information in a corporate network. To add, access, and
process data stored in a computer database, you need a database
management system such as MySQL Server. Since computers are very
good at handling large amounts of data, database management
systems play a central role in computing, as standalone utilities,
or as parts of other applications.

* MySQL is a relational database management system.

A relational database stores data in separate tables rather than
putting all the data in one big storeroom. This adds speed and
flexibility. The SQL part of `MySQL' stands for `Structured Query
Language.' SQL is the most common standardized language used to
access databases and is defined by the ANSI/ISO SQL Standard. The
SQL standard has been evolving since 1986 and several versions
exist. In this manual, `SQL-92' refers to the standard released in
1992, `SQL:1999' refers to the standard released in 1999, and
`SQL:2003' refers to the current version of the standard. We use
the phrase `the SQL standard' to mean the current version of the
SQL Standard at any time.

* MySQL software is Open Source.

Open Source means that it is possible for anyone to use and modify
the software. Anybody can download the MySQL software from the
Internet and use it without paying anything. If you wish, you may
study the source code and change it to suit your needs. The MySQL
software uses the GPL (GNU General Public License),
`http://www.fsf.org/licenses/', to define what you may and may not
do with the software in different situations. If you feel
uncomfortable with the GPL or need to embed MySQL code into a
commercial application, you can buy a commercially licensed
version from us. See the MySQL Licensing Overview for more
information (http://www.mysql.com/company/legal/licensing/).

* The MySQL Database Server is very fast, reliable, and easy to use.

If that is what you are looking for, you should give it a try.
MySQL Server also has a practical set of features developed in
close cooperation with our users. You can find a performance
comparison of MySQL Server with other database managers on our
benchmark page. See *Note mysql-benchmarks::.

MySQL Server was originally developed to handle large databases
much faster than existing solutions and has been successfully used
in highly demanding production environments for several years.
Although under constant development, MySQL Server today offers a
rich and useful set of functions. Its connectivity, speed, and
security make MySQL Server highly suited for accessing databases
on the Internet.

* MySQL Server works in client/server or embedded systems.

The MySQL Database Software is a client/server system that
consists of a multi-threaded SQL server that supports different
backends, several different client programs and libraries,
administrative tools, and a wide range of application programming
interfaces (APIs).

We also provide MySQL Server as an embedded multi-threaded library
that you can link into your application to get a smaller, faster,
easier-to-manage standalone product.

* A large amount of contributed MySQL software is available.

It is very likely that your favorite application or language
supports the MySQL Database Server.

The official way to pronounce `MySQL' is `My Ess Que Ell' (not `my
sequel'), but we do not mind if you pronounce it as `my sequel' or in
some other localized way.

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2.3.2 History of MySQL
----------------------

We started out with the intention of using the `mSQL' database system
to connect to our tables using our own fast low-level (ISAM) routines.
However, after some testing, we came to the conclusion that `mSQL' was
not fast enough or flexible enough for our needs. This resulted in a
new SQL interface to our database but with almost the same API
interface as `mSQL'. This API was designed to enable third-party code
that was written for use with `mSQL' to be ported easily for use with
MySQL.

MySQL is named after co-founder Monty Widenius's daughter, My.

The name of the MySQL Dolphin (our logo) is `Sakila,' which was chosen
from a huge list of names suggested by users in our `Name the Dolphin'
contest. The winning name was submitted by Ambrose Twebaze, an Open
Source software developer from Swaziland, Africa. According to Ambrose,
the feminine name Sakila has its roots in SiSwati, the local language
of Swaziland. Sakila is also the name of a town in Arusha, Tanzania,
near Ambrose's country of origin, Uganda.

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2.3.3 The Main Features of MySQL
--------------------------------

This section describes some of the important characteristics of the
MySQL Database Software. See also *Note development-history::. In most
respects, the roadmap applies to all versions of MySQL. For information
about features as they are introduced into MySQL on a series-specific
basis, see the `In a Nutshell' section of the appropriate Manual:

* MySQL 5.0: *Note MySQL 5.0 in a Nutshell: mysql-nutshell.

* MySQL 5.1: MySQL 5.1 in a Nutshell
(http://dev.mysql.com/doc/refman/5.1/en/mysql-nutshell.html)

* MySQL 5.5: MySQL 5.5 in a Nutshell
(http://dev.mysql.com/doc/refman/5.5/en/mysql-nutshell.html)

Internals and Portability:

* Written in C and C++.

* Tested with a broad range of different compilers.

* Works on many different platforms. See *Note supported-os::.

* For portability, uses `CMake' in MySQL 5.5 and up. Previous series
use GNU Automake, Autoconf, and Libtool.

* Tested with Purify (a commercial memory leakage detector) as well
as with Valgrind, a GPL tool
(`http://developer.kde.org/~sewardj/').

* Uses multi-layered server design with independent modules.

* Designed to be fully multi-threaded using kernel threads, to
easily use multiple CPUs if they are available.

* Provides transactional and nontransactional storage engines.

* Uses very fast B-tree disk tables (`MyISAM') with index
compression.

* Designed to make it relatively easy to add other storage engines.
This is useful if you want to provide an SQL interface for an
in-house database.

* Uses a very fast thread-based memory allocation system.

* Executes very fast joins using an optimized nested-loop join.

* Implements in-memory hash tables, which are used as temporary
tables.

* Implements SQL functions using a highly optimized class library
that should be as fast as possible. Usually there is no memory
allocation at all after query initialization.

* Provides the server as a separate program for use in a
client/server networked environment, and as a library that can be
embedded (linked) into standalone applications. Such applications
can be used in isolation or in environments where no network is
available.

Data Types:

* Many data types: signed/unsigned integers 1, 2, 3, 4, and 8 bytes
long, *Note `FLOAT': numeric-types, *Note `DOUBLE': numeric-types,
*Note `CHAR': char, *Note `VARCHAR': char, *Note `BINARY':
binary-varbinary, *Note `VARBINARY': binary-varbinary, *Note
`TEXT': blob, *Note `BLOB': blob, *Note `DATE': datetime, *Note
`TIME': time, *Note `DATETIME': datetime, *Note `TIMESTAMP':
datetime, *Note `YEAR': year, *Note `SET': set, *Note `ENUM':
enum, and OpenGIS spatial types. See *Note data-types::.

* Fixed-length and variable-length string types.

Statements and Functions:

* Full operator and function support in the *Note `SELECT': select.
list and `WHERE' clause of queries. For example:

mysql> SELECT CONCAT(first_name, ' ', last_name)
-> FROM citizen
-> WHERE income/dependents > 10000 AND age > 30;

* Full support for SQL `GROUP BY' and `ORDER BY' clauses. Support
for group functions (`COUNT()', `AVG()', `STD()', `SUM()', `MAX()',
`MIN()', and `GROUP_CONCAT()').

* Support for `LEFT OUTER JOIN' and `RIGHT OUTER JOIN' with both
standard SQL and ODBC syntax.

* Support for aliases on tables and columns as required by standard
SQL.

* Support for *Note `DELETE': delete, *Note `INSERT': insert, *Note
`REPLACE': replace, and *Note `UPDATE': update. to return the
number of rows that were changed (affected), or to return the
number of rows matched instead by setting a flag when connecting
to the server.

* Support for MySQL-specific *Note `SHOW': show. statements that
retrieve information about databases, storage engines, tables, and
indexes. MySQL 5.0 adds support for the `INFORMATION_SCHEMA'
database, implemented according to standard SQL.

* An *Note `EXPLAIN': explain. statement to show how the optimizer
resolves a query.

* Independence of function names from table or column names. For
example, `ABS' is a valid column name. The only restriction is
that for a function call, no spaces are permitted between the
function name and the ``('' that follows it. See *Note
reserved-words::.

* You can refer to tables from different databases in the same
statement.

Security:

* A privilege and password system that is very flexible and secure,
and that enables host-based verification.

* Password security by encryption of all password traffic when you
connect to a server.

Scalability and Limits:

* Support for large databases. We use MySQL Server with databases
that contain 50 million records. We also know of users who use
MySQL Server with 200,000 tables and about 5,000,000,000 rows.

* Support for up to 64 indexes per table (32 before MySQL 4.1.2).
Each index may consist of 1 to 16 columns or parts of columns. The
maximum index width is 1000 bytes (767 for `InnoDB'); before MySQL
4.1.2, the limit is 500 bytes. An index may use a prefix of a
column for *Note `CHAR': char, *Note `VARCHAR': char, *Note
`BLOB': blob, or *Note `TEXT': blob. column types.

Connectivity:

* Clients can connect to MySQL Server using several protocols:

* Clients can connect using TCP/IP sockets on any platform.

* On Windows systems in the NT family (NT, 2000, XP, 2003, or
Vista), clients can connect using named pipes if the server
is started with the `--enable-named-pipe' option. In MySQL
4.1 and higher, Windows servers also support shared-memory
connections if started with the `--shared-memory' option.
Clients can connect through shared memory by using the
`--protocol=memory' option.

* On Unix systems, clients can connect using Unix domain socket
files.

* MySQL client programs can be written in many languages. A client
library written in C is available for clients written in C or C++,
or for any language that provides C bindings.

* APIs for C, C++, Eiffel, Java, Perl, PHP, Python, Ruby, and Tcl
are available, enabling MySQL clients to be written in many
languages. See *Note connectors-apis::.

* The Connector/ODBC (MyODBC) interface provides MySQL support for
client programs that use ODBC (Open Database Connectivity)
connections. For example, you can use MS Access to connect to your
MySQL server. Clients can be run on Windows or Unix. MyODBC
source is available. All ODBC 2.5 functions are supported, as are
many others. See *Note connector-odbc::.

* The Connector/J interface provides MySQL support for Java client
programs that use JDBC connections. Clients can be run on Windows
or Unix. Connector/J source is available. See *Note connector-j::.

* MySQL Connector/NET enables developers to easily create .NET
applications that require secure, high-performance data
connectivity with MySQL. It implements the required ADO.NET
interfaces and integrates into ADO.NET aware tools. Developers can
build applications using their choice of .NET languages. MySQL
Connector/NET is a fully managed ADO.NET driver written in 100%
pure C#. See *Note connector-net::.

Localization:

* The server can provide error messages to clients in many
languages. See *Note error-message-language::.

* Full support for several different character sets, including
`latin1' (cp1252), `german', `big5', `ujis', and more. For
example, the Scandinavian characters ``aa'', ``a"'' and ``o"'' are
permitted in table and column names. Unicode support is available
as of MySQL 4.1.

* All data is saved in the chosen character set.

* Sorting and comparisons are done according to the chosen character
set and collation (using `latin1' and Swedish collation by
default). It is possible to change this when the MySQL server is
started. To see an example of very advanced sorting, look at the
Czech sorting code. MySQL Server supports many different character
sets that can be specified at compile time and runtime.

* As of MySQL 4.1, the server time zone can be changed dynamically,
and individual clients can specify their own time zone. *Note
time-zone-support::.

Clients and Tools:

* MySQL includes several client and utility programs. These include
both command-line programs such as *Note `mysqldump': mysqldump.
and *Note `mysqladmin': mysqladmin, and graphical programs such as
MySQL Administrator and MySQL Query Browser.

* MySQL Server has built-in support for SQL statements to check,
optimize, and repair tables. These statements are available from
the command line through the *Note `mysqlcheck': mysqlcheck.
client. MySQL also includes *Note `myisamchk': myisamchk, a very
fast command-line utility for performing these operations on
`MyISAM' tables. See *Note programs::.

* MySQL programs can be invoked with the `--help' or `-?' option to
obtain online assistance.

File: manual.info, Node: development-history, Next: mysql-nutshell, Prev: what-is, Up: introduction

2.4 MySQL Development History
=============================

This section describes the general MySQL development history, including
major features implemented in or planned for various MySQL releases.
The following sections provide information for each release series.

The current production release series is MySQL 5.1, which was declared
stable for production use as of MySQL 5.1.30, released in November
2008. The previous production release series was MySQL 5.0, which was
declared stable for production use as of MySQL 5.0.15, released in
October 2005. `General Availability status' means that future 5.1 and
5.0 development is limited only to bugfixes. For the older MySQL 4.1,
4.0, and 3.23 series, only critical bugfixes are made.

Before upgrading from one release series to the next, please see the
notes in *Note upgrading::.

The most requested features and the versions in which they were
implemented are summarized in the following table.

Feature MySQL Series
Unions 4.0
Subqueries 4.1
R-trees 4.1 (for the `MyISAM' storage engine)
Stored procedures and 5.0
functions
Views 5.0
Cursors 5.0
XA transactions 5.0
Triggers 5.0 and 5.1
Event scheduler 5.1
Partitioning 5.1
Pluggable storage 5.1
engine API
Plugin API 5.1
InnoDB Plugin 5.1
Row-based replication 5.1
Server log tables 5.1

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2.5 What Is New in MySQL 5.0
============================

The following features are implemented in MySQL 5.0:

* **Note `BIT': numeric-types. Data Type*: Can be used to store
numbers in binary notation. See *Note numeric-type-overview::.

* *Cursors*: Elementary support for server-side cursors. For
information about using cursors within stored routines, see *Note
cursors::. For information about using cursors from within the C
API, see *Note mysql-stmt-attr-set::.

* *Information Schema*: The introduction of the `INFORMATION_SCHEMA'
database in MySQL 5.0 provided a standards-compliant means for
accessing the MySQL Server's metadata; that is, data about the
databases (schemas) on the server and the objects which they
contain. See *Note information-schema::.

* *Instance Manager*: Can be used to start and stop the MySQL
Server, even from a remote host. See *Note instance-manager::.

* *Precision Math*: MySQL 5.0 introduced stricter criteria for
acceptance or rejection of data, and implemented a new library for
fixed-point arithmetic. These contributed to a much higher degree
of accuracy for mathematical operations and greater control over
invalid values. See *Note precision-math::.

* *Storage Engines*: Storage engines added in MySQL 5.0 include
`ARCHIVE' and `FEDERATED'. See *Note archive-storage-engine::, and
*Note federated-storage-engine::.

* *Stored Routines*: MySQL 5.0 added support for stored procedures
and stored functions. See *Note stored-routines::.

* *Triggers*: MySQL 5.0 added limited support for triggers. See
*Note triggers::.

* *Views*: MySQL 5.0 added support for named, updatable views. See
*Note views::.

* *Strict Mode and Standard Error Handling*: MySQL 5.0 added a
strict mode where by it follows standard SQL in a number of ways
in which it did not previously. Support for standard SQLSTATE
error messages was also implemented. See *Note server-sql-mode::.

* **Note `VARCHAR': char. Data Type*: The effective maximum length
of a *Note `VARCHAR': char. column was increased to 65,535 bytes,
and stripping of trailing whitespace was eliminated. (The actual
maximum length of a *Note `VARCHAR': char. is determined by the
maximum row size and the character set you use. The maximum
_effective_ column length is subject to a row size of 65,535
bytes, which is shared among all columns.) See *Note
string-types::.

* *XA Transactions*: See *Note xa::.

* *Performance enhancements*: A number of improvements were made in
MySQL 5.0 to improve the speed of certain types of queries and in
the handling of certain types. These include:

* MySQL 5.0 introduces a new `greedy' optimizer which can
greatly reduce the time required to arrive at a query
execution plan. This is particularly noticeable where several
tables are to be joined and no good join keys can otherwise
be found. Without the greedy optimizer, the complexity of the
search for an execution plan is calculated as `N!', where N
is the number of tables to be joined. The greedy optimizer
reduces this to `N!/(D-1)!', where D is the depth of the
search. Although the greedy optimizer does not guarantee the
best possible of all execution plans (this is currently being
worked on), it can reduce the time spent arriving at an
execution plan for a join involving a great many tables--30,
40, or more--by a factor of as much as 1,000. This should
eliminate most if not all situations where users thought that
the optimizer had hung when trying to perform joins across
many tables.

* Use of the _Index Merge_ method to obtain better optimization
of `AND' and `OR' relations over different keys. (Previously,
these were optimized only where both relations in the `WHERE'
clause involved the same key.) This also applies to other
one-to-one comparison operators (`>', `<', and so on),
including `=' and the `IN' operator. This means that MySQL
can use multiple indexes in retrieving results for conditions
such as `WHERE key1 > 4 OR key2 < 7' and even combinations of
conditions such as `WHERE (key1 > 4 OR key2 < 7) AND (key3 >=
10 OR key4 = 1)'. See *Note index-merge-optimization::.

* A new equality detector finds and optimizes `hidden'
equalities in joins. For example, a `WHERE' clause such as

t1.c1=t2.c2 AND t2.c2=t3.c3 AND t1.c1 < 5

implies these other conditions

t1.c1=t3.c3 AND t2.c2 < 5 AND t3.c3 < 5

These optimizations can be applied with any combination of
`AND' and `OR' operators. See *Note
nested-join-optimization::, and *Note
outer-join-simplification::.

* Optimization of `NOT IN' and `NOT BETWEEN' relations,
reducing or eliminating table scans for queries making use of
them by mean of range analysis. The performance of MySQL with
regard to these relations now matches its performance with
regard to `IN' and `BETWEEN'.

* The *Note `VARCHAR': char. data type as implemented in MySQL
5.0 is more efficient than in previous versions, due to the
elimination of the old (and nonstandard) removal of trailing
spaces during retrieval.

* The addition of a true *Note `BIT': numeric-types. column
type; this type is much more efficient for storage and
retrieval of Boolean values than the workarounds required in
MySQL in versions previous to 5.0.

* *Performance Improvements in the `InnoDB' Storage Engine*:

* New compact storage format which can save up to 20% of
the disk space required in previous MySQL/`InnoDB'
versions.

* Faster recovery from a failed or aborted *Note `ALTER
TABLE': alter-table.

* Faster implementation of *Note `TRUNCATE TABLE':
truncate-table.

(See *Note innodb-storage-engine::.)

* *Performance Improvements in the *Note `NDBCLUSTER':
mysql-cluster. Storage Engine*:

* Faster handling of queries that use `IN' and `BETWEEN'.

* *Condition pushdown*: In cases involving the comparison
of an unindexed column with a constant, this condition is
`pushed down' to the cluster where it is evaluated in
all partitions simultaneously, eliminating the need to
send nonmatching records over the network. This can make
such queries 10 to 100 times faster than in MySQL 4.1
Cluster.

See *Note explain::, for more information.

(See *Note mysql-cluster::.)

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2.6 MySQL Information Sources
=============================

* Menu:

* mailing-lists:: MySQL Mailing Lists
* forums:: MySQL Community Support at the MySQL Forums
* irc:: MySQL Community Support on Internet Relay Chat (IRC)
* mysql-enterprise-information:: MySQL Enterprise

This section lists sources of additional information that you may find
helpful, such as the MySQL mailing lists and user forums, and Internet
Relay Chat.

File: manual.info, Node: mailing-lists, Next: forums, Prev: information-sources, Up: information-sources

2.6.1 MySQL Mailing Lists
-------------------------

* Menu:

* mailing-list-use:: Guidelines for Using the Mailing Lists

This section introduces the MySQL mailing lists and provides guidelines
as to how the lists should be used. When you subscribe to a mailing
list, you receive all postings to the list as email messages. You can
also send your own questions and answers to the list.

To subscribe to or unsubscribe from any of the mailing lists described
in this section, visit `http://lists.mysql.com/'. For most of them, you
can select the regular version of the list where you get individual
messages, or a digest version where you get one large message per day.

Please _do not_ send messages about subscribing or unsubscribing to any
of the mailing lists, because such messages are distributed
automatically to thousands of other users.

Your local site may have many subscribers to a MySQL mailing list. If
so, the site may have a local mailing list, so that messages sent from
`lists.mysql.com' to your site are propagated to the local list. In
such cases, please contact your system administrator to be added to or
dropped from the local MySQL list.

If you wish to have traffic for a mailing list go to a separate mailbox
in your mail program, set up a filter based on the message headers. You
can use either the `List-ID:' or `Delivered-To:' headers to identify
list messages.

The MySQL mailing lists are as follows:

* `announce'

The list for announcements of new versions of MySQL and related
programs. This is a low-volume list to which all MySQL users
should subscribe.

* `mysql'

The main list for general MySQL discussion. Please note that some
topics are better discussed on the more-specialized lists. If you
post to the wrong list, you may not get an answer.

* `bugs'

The list for people who want to stay informed about issues
reported since the last release of MySQL or who want to be
actively involved in the process of bug hunting and fixing. See
*Note bug-reports::.

* `internals'

The list for people who work on the MySQL code. This is also the
forum for discussions on MySQL development and for posting patches.

* `mysqldoc'

The list for people who work on the MySQL documentation.

* `benchmarks'

The list for anyone interested in performance issues. Discussions
concentrate on database performance (not limited to MySQL), but
also include broader categories such as performance of the kernel,
file system, disk system, and so on.

* `packagers'

The list for discussions on packaging and distributing MySQL.
This is the forum used by distribution maintainers to exchange
ideas on packaging MySQL and on ensuring that MySQL looks and
feels as similar as possible on all supported platforms and
operating systems.

* `java'

The list for discussions about the MySQL server and Java. It is
mostly used to discuss JDBC drivers such as MySQL Connector/J.

* `win32'

The list for all topics concerning the MySQL software on Microsoft
operating systems, such as Windows 9x, Me, NT, 2000, XP, and 2003.

* `myodbc'

The list for all topics concerning connecting to the MySQL server
with ODBC.

* `gui-tools'

The list for all topics concerning MySQL graphical user interface
tools such as `MySQL Administrator' and `MySQL Query Browser'.

* `cluster'

The list for discussion of MySQL Cluster.

* `dotnet'

The list for discussion of the MySQL server and the .NET platform.
It is mostly related to MySQL Connector/Net.

* `plusplus'

The list for all topics concerning programming with the C++ API
for MySQL.

* `perl'

The list for all topics concerning Perl support for MySQL with
`DBD::mysql'.

If you're unable to get an answer to your questions from a MySQL
mailing list or forum, one option is to purchase support from Oracle.
This puts you in direct contact with MySQL developers.

The following MySQL mailing lists are in languages other than English.
These lists are not operated by Oracle.

* `<mysql-france-subscribe@yahoogroups.com>'

A French mailing list.

* `<list@tinc.net>'

A Korean mailing list. To subscribe, email `subscribe mysql
your@email.address' to this list.

* `<mysql-de-request@lists.4t2.com>'

A German mailing list. To subscribe, email `subscribe mysql-de
your@email.address' to this list. You can find information about
this mailing list at `http://www.4t2.com/mysql/'.

* `<mysql-br-request@listas.linkway.com.br>'

A Portuguese mailing list. To subscribe, email `subscribe mysql-br
your@email.address' to this list.

* `<mysql-alta@elistas.net>'

A Spanish mailing list. To subscribe, email `subscribe mysql
your@email.address' to this list.

File: manual.info, Node: mailing-list-use, Prev: mailing-lists, Up: mailing-lists

2.6.1.1 Guidelines for Using the Mailing Lists
..............................................

Please do not post mail messages from your browser with HTML mode
turned on. Many users do not read mail with a browser.

When you answer a question sent to a mailing list, if you consider your
answer to have broad interest, you may want to post it to the list
instead of replying directly to the individual who asked. Try to make
your answer general enough that people other than the original poster
may benefit from it. When you post to the list, please make sure that
your answer is not a duplication of a previous answer.

Try to summarize the essential part of the question in your reply. Do
not feel obliged to quote the entire original message.

When answers are sent to you individually and not to the mailing list,
it is considered good etiquette to summarize the answers and send the
summary to the mailing list so that others may have the benefit of
responses you received that helped you solve your problem.

File: manual.info, Node: forums, Next: irc, Prev: mailing-lists, Up: information-sources

2.6.2 MySQL Community Support at the MySQL Forums
-------------------------------------------------

The forums at `http://forums.mysql.com' are an important community
resource. Many forums are available, grouped into these general
categories:

* Migration

* MySQL Usage

* MySQL Connectors

* Programming Languages

* Tools

* 3rd-Party Applications

* Storage Engines

* MySQL Technology

* SQL Standards

* Business

File: manual.info, Node: irc, Next: mysql-enterprise-information, Prev: forums, Up: information-sources

2.6.3 MySQL Community Support on Internet Relay Chat (IRC)
----------------------------------------------------------

In addition to the various MySQL mailing lists and forums, you can find
experienced community people on Internet Relay Chat (IRC). These are
the best networks/channels currently known to us:

*freenode* (see `http://www.freenode.net/' for servers)

* `#mysql' is primarily for MySQL questions, but other database and
general SQL questions are welcome. Questions about PHP, Perl, or
C in combination with MySQL are also common.

If you are looking for IRC client software to connect to an IRC
network, take a look at `xChat' (`http://www.xchat.org/'). X-Chat (GPL
licensed) is available for Unix as well as for Windows platforms (a free
Windows build of X-Chat is available at
`http://www.silverex.org/download/').

File: manual.info, Node: mysql-enterprise-information, Prev: irc, Up: information-sources

2.6.4 MySQL Enterprise
----------------------

Oracle offers technical support in the form of MySQL Enterprise. For
organizations that rely on the MySQL DBMS for business-critical
production applications, MySQL Enterprise is a commercial subscription
offering which includes:

* MySQL Enterprise Server

* MySQL Enterprise Monitor

* Monthly Rapid Updates and Quarterly Service Packs

* MySQL Knowledge Base

* 24x7 Technical and Consultative Support

MySQL Enterprise is available in multiple tiers, giving you the
flexibility to choose the level of service that best matches your
needs. For more information, see MySQL Enterprise
(http://www.mysql.com/products/enterprise/).

File: manual.info, Node: bug-reports, Next: compatibility, Prev: information-sources, Up: introduction

2.7 How to Report Bugs or Problems
==================================

Before posting a bug report about a problem, please try to verify that
it is a bug and that it has not been reported already:

* Start by searching the MySQL online manual at
`http://dev.mysql.com/doc/'. We try to keep the manual up to date
by updating it frequently with solutions to newly found problems.
The change history (`http://dev.mysql.com/doc/mysql/en/news.html')
can be particularly useful since it is quite possible that a newer
version contains a solution to your problem.

* If you get a parse error for an SQL statement, please check your
syntax closely. If you cannot find something wrong with it, it is
extremely likely that your current version of MySQL Server doesn't
support the syntax you are using. If you are using the current
version and the manual doesn't cover the syntax that you are
using, MySQL Server doesn't support your statement. In this case,
your options are to implement the syntax yourself or email
<licensing@mysql.com> and ask for an offer to implement it.

If the manual covers the syntax you are using, but you have an
older version of MySQL Server, you should check the MySQL change
history to see when the syntax was implemented. In this case, you
have the option of upgrading to a newer version of MySQL Server.

* For solutions to some common problems, see *Note problems::.

* Search the bugs database at `http://bugs.mysql.com/' to see
whether the bug has been reported and fixed.

* Search the MySQL mailing list archives at
`http://lists.mysql.com/'. See *Note mailing-lists::.

* You can also use http://www.mysql.com/search/ to search all the
Web pages (including the manual) that are located at the MySQL Web
site.

If you cannot find an answer in the manual, the bugs database, or the
mailing list archives, check with your local MySQL expert. If you still
cannot find an answer to your question, please use the following
guidelines for reporting the bug.

Bugs posted in the bugs database at `http://bugs.mysql.com/' that are
corrected for a given release are noted in the change history.

If you have found a sensitive security bug in MySQL, you can send email
to <security@mysql.com>.

To discuss problems with other users, you can use one of the MySQL
mailing lists. *Note mailing-lists::.

Writing a good bug report takes patience, but doing it right the first
time saves time both for us and for yourself. A good bug report,
containing a full test case for the bug, makes it very likely that we
will fix the bug in the next release. This section helps you write your
report correctly so that you do not waste your time doing things that
may not help us much or at all. Please read this section carefully and
make sure that all the information described here is included in your
report.

Preferably, you should test the problem using the latest production or
development version of MySQL Server before posting. Anyone should be
able to repeat the bug by just using `mysql test < script_file' on your
test case or by running the shell or Perl script that you include in
the bug report. Any bug that we are able to repeat has a high chance of
being fixed in the next MySQL release.

It is most helpful when a good description of the problem is included
in the bug report. That is, give a good example of everything you did
that led to the problem and describe, in exact detail, the problem
itself. The best reports are those that include a full example showing
how to reproduce the bug or problem. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

Remember that it is possible for us to respond to a report containing
too much information, but not to one containing too little. People
often omit facts because they think they know the cause of a problem
and assume that some details do not matter. A good principle to follow
is that if you are in doubt about stating something, state it. It is
faster and less troublesome to write a couple more lines in your report
than to wait longer for the answer if we must ask you to provide
information that was missing from the initial report.

The most common errors made in bug reports are (a) not including the
version number of the MySQL distribution that you use, and (b) not
fully describing the platform on which the MySQL server is installed
(including the platform type and version number). These are highly
relevant pieces of information, and in 99 cases out of 100, the bug
report is useless without them. Very often we get questions like, `Why
doesn't this work for me?' Then we find that the feature requested
wasn't implemented in that MySQL version, or that a bug described in a
report has been fixed in newer MySQL versions. Errors often are
platform-dependent. In such cases, it is next to impossible for us to
fix anything without knowing the operating system and the version
number of the platform.

If you compiled MySQL from source, remember also to provide information
about your compiler if it is related to the problem. Often people find
bugs in compilers and think the problem is MySQL-related. Most
compilers are under development all the time and become better version
by version. To determine whether your problem depends on your compiler,
we need to know what compiler you used. Note that every compiling
problem should be regarded as a bug and reported accordingly.

If a program produces an error message, it is very important to include
the message in your report. If we try to search for something from the
archives, it is better that the error message reported exactly matches
the one that the program produces. (Even the lettercase should be
observed.) It is best to copy and paste the entire error message into
your report. You should never try to reproduce the message from memory.

If you have a problem with Connector/ODBC (MyODBC), please try to
generate a trace file and send it with your report. See the MyODBC
section of *Note connectors-apis::.

If your report includes long query output lines from test cases that
you run with the *Note `mysql': mysql. command-line tool, you can make
the output more readable by using the `--vertical' option or the `\G'
statement terminator. The *Note `EXPLAIN SELECT': explain. example
later in this section demonstrates the use of `\G'.

Please include the following information in your report:

* The version number of the MySQL distribution you are using (for
example, MySQL 5.0.19). You can find out which version you are
running by executing *Note `mysqladmin version': mysqladmin. The
*Note `mysqladmin': mysqladmin. program can be found in the `bin'
directory under your MySQL installation directory.

* The manufacturer and model of the machine on which you experience
the problem.

* The operating system name and version. If you work with Windows,
you can usually get the name and version number by double-clicking
your My Computer icon and pulling down the `Help/About Windows'
menu. For most Unix-like operating systems, you can get this
information by executing the command `uname -a'.

* Sometimes the amount of memory (real and virtual) is relevant. If
in doubt, include these values.

* If you are using a source distribution of the MySQL software,
include the name and version number of the compiler that you used.
If you have a binary distribution, include the distribution name.

* If the problem occurs during compilation, include the exact error
messages and also a few lines of context around the offending code
in the file where the error occurs.

* If *Note `mysqld': mysqld. died, you should also report the
statement that crashed *Note `mysqld': mysqld. You can usually get
this information by running *Note `mysqld': mysqld. with query
logging enabled, and then looking in the log after *Note `mysqld':
mysqld. crashes. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* If a database table is related to the problem, include the output
from the `SHOW CREATE TABLE DB_NAME.TBL_NAME' statement in the bug
report. This is a very easy way to get the definition of any table
in a database. The information helps us create a situation
matching the one that you have experienced.

* The SQL mode in effect when the problem occurred can be
significant, so please report the value of the `sql_mode' system
variable. For stored procedure, stored function, and trigger
objects, the relevant `sql_mode' value is the one in effect when
the object was created. For a stored procedure or function, the
*Note `SHOW CREATE PROCEDURE': show-create-procedure. or *Note
`SHOW CREATE FUNCTION': show-create-function. statement shows the
relevant SQL mode, or you can query `INFORMATION_SCHEMA' for the
information:

SELECT ROUTINE_SCHEMA, ROUTINE_NAME, SQL_MODE
FROM INFORMATION_SCHEMA.ROUTINES;

For triggers, you can use this statement:

SELECT EVENT_OBJECT_SCHEMA, EVENT_OBJECT_TABLE, TRIGGER_NAME, SQL_MODE
FROM INFORMATION_SCHEMA.TRIGGERS;

* For performance-related bugs or problems with *Note `SELECT':
select. statements, you should always include the output of
`EXPLAIN SELECT ...', and at least the number of rows that the
*Note `SELECT': select. statement produces. You should also
include the output from `SHOW CREATE TABLE TBL_NAME' for each table
that is involved. The more information you provide about your
situation, the more likely it is that someone can help you.

The following is an example of a very good bug report. The
statements are run using the *Note `mysql': mysql. command-line
tool. Note the use of the `\G' statement terminator for statements
that would otherwise provide very long output lines that are
difficult to read.

mysql> SHOW VARIABLES;
mysql> SHOW COLUMNS FROM ...\G
<OUTPUT FROM SHOW COLUMNS>
mysql> EXPLAIN SELECT ...\G
<OUTPUT FROM EXPLAIN>
mysql> FLUSH STATUS;
mysql> SELECT ...;
<A SHORT VERSION OF THE OUTPUT FROM SELECT,
INCLUDING THE TIME TAKEN TO RUN THE QUERY>
mysql> SHOW STATUS;
<OUTPUT FROM SHOW STATUS>

* If a bug or problem occurs while running *Note `mysqld': mysqld,
try to provide an input script that reproduces the anomaly. This
script should include any necessary source files. The more closely
the script can reproduce your situation, the better. If you can
make a reproducible test case, you should upload it to be attached
to the bug report.

If you cannot provide a script, you should at least include the
output from *Note `mysqladmin variables extended-status
processlist': mysqladmin. in your report to provide some
information on how your system is performing.

* If you cannot produce a test case with only a few rows, or if the
test table is too big to be included in the bug report (more than
10 rows), you should dump your tables using *Note `mysqldump':
mysqldump. and create a `README' file that describes your problem.
Create a compressed archive of your files using `tar' and `gzip' or
`zip', and use FTP to transfer the archive to
`ftp://ftp.mysql.com/pub/mysql/upload/'. Then enter the problem
into our bugs database at `http://bugs.mysql.com/'.

* If you believe that the MySQL server produces a strange result
from a statement, include not only the result, but also your
opinion of what the result should be, and an explanation
describing the basis for your opinion.

* When you provide an example of the problem, it is better to use
the table names, variable names, and so forth that exist in your
actual situation than to come up with new names. The problem could
be related to the name of a table or variable. These cases are
rare, perhaps, but it is better to be safe than sorry. After all,
it should be easier for you to provide an example that uses your
actual situation, and it is by all means better for us. If you
have data that you do not want to be visible to others in the bug
report, you can use FTP to transfer it to
`ftp://ftp.mysql.com/pub/mysql/upload/'. If the information is
really top secret and you do not want to show it even to us, go
ahead and provide an example using other names, but please regard
this as the last choice.

* Include all the options given to the relevant programs, if
possible. For example, indicate the options that you use when you
start the *Note `mysqld': mysqld. server, as well as the options
that you use to run any MySQL client programs. The options to
programs such as *Note `mysqld': mysqld. and *Note `mysql': mysql,
and to the `configure' script, are often key to resolving problems
and are very relevant. It is never a bad idea to include them. If
your problem involves a program written in a language such as Perl
or PHP, please include the language processor's version number, as
well as the version for any modules that the program uses. For
example, if you have a Perl script that uses the `DBI' and
`DBD::mysql' modules, include the version numbers for Perl, `DBI',
and `DBD::mysql'.

* If your question is related to the privilege system, please
include the output of *Note `mysqlaccess': mysqlaccess, the output
of *Note `mysqladmin reload': mysqladmin, and all the error
messages you get when trying to connect. When you test your
privileges, you should first run *Note `mysqlaccess': mysqlaccess.
After this, execute *Note `mysqladmin reload version': mysqladmin.
and try to connect with the program that gives you trouble. *Note
`mysqlaccess': mysqlaccess. can be found in the `bin' directory
under your MySQL installation directory.

* If you have a patch for a bug, do include it. But do not assume
that the patch is all we need, or that we can use it, if you do
not provide some necessary information such as test cases showing
the bug that your patch fixes. We might find problems with your
patch or we might not understand it at all. If so, we cannot use
it.

If we cannot verify the exact purpose of the patch, we will not
use it. Test cases help us here. Show that the patch handles all
the situations that may occur. If we find a borderline case (even
a rare one) where the patch will not work, it may be useless.

* Guesses about what the bug is, why it occurs, or what it depends
on are usually wrong. Even the MySQL team cannot guess such things
without first using a debugger to determine the real cause of a
bug.

* Indicate in your bug report that you have checked the reference
manual and mail archive so that others know you have tried to
solve the problem yourself.

* If the problem is that your data appears corrupt or you get errors
when you access a particular table, you should first check your
tables and then try to repair them with *Note `CHECK TABLE':
check-table. and *Note `REPAIR TABLE': repair-table. or with *Note
`myisamchk': myisamchk. See *Note server-administration::.

If you are running Windows, please verify the value of
`lower_case_table_names' using the `SHOW VARIABLES LIKE
'lower_case_table_names'' statement. This variable affects how the
server handles lettercase of database and table names. Its effect
for a given value should be as described in *Note
identifier-case-sensitivity::.

* If you often get corrupted tables, you should try to find out when
and why this happens. In this case, the error log in the MySQL
data directory may contain some information about what happened.
(This is the file with the `.err' suffix in the name.) See *Note
error-log::. Please include any relevant information from this
file in your bug report. Normally *Note `mysqld': mysqld. should
_never_ crash a table if nothing killed it in the middle of an
update. If you can find the cause of *Note `mysqld': mysqld.
dying, it is much easier for us to provide you with a fix for the
problem. See *Note what-is-crashing::.

* If possible, download and install the most recent version of MySQL
Server and check whether it solves your problem. All versions of
the MySQL software thoroughly tested and should work without
problems. We believe in making everything as backward-compatible
as possible, and you should be able to switch MySQL versions
without difficulty. See *Note which-version::.

File: manual.info, Node: compatibility, Next: credits, Prev: bug-reports, Up: introduction

2.8 MySQL Standards Compliance
==============================

* Menu:

* standards:: What Standards MySQL Follows
* sql-mode:: Selecting SQL Modes
* ansi-mode:: Running MySQL in ANSI Mode
* extensions-to-ansi:: MySQL Extensions to Standard SQL
* differences-from-ansi:: MySQL Differences from Standard SQL
* constraints:: How MySQL Deals with Constraints

This section describes how MySQL relates to the ANSI/ISO SQL standards.
MySQL Server has many extensions to the SQL standard, and here you can
find out what they are and how to use them. You can also find
information about functionality missing from MySQL Server, and how to
work around some of the differences.

The SQL standard has been evolving since 1986 and several versions
exist. In this manual, `SQL-92' refers to the standard released in
1992, `SQL:1999' refers to the standard released in 1999, `SQL:2003'
refers to the standard released in 2003, and `SQL:2008' refers to the
most recent version of the standard, released in 2008. We use the
phrase `the SQL standard' or `standard SQL' to mean the current version
of the SQL Standard at any time.

One of our main goals with the product is to continue to work toward
compliance with the SQL standard, but without sacrificing speed or
reliability. We are not afraid to add extensions to SQL or support for
non-SQL features if this greatly increases the usability of MySQL
Server for a large segment of our user base. The *Note `HANDLER':
handler. interface is an example of this strategy. See *Note handler::.

We continue to support transactional and nontransactional databases to
satisfy both mission-critical 24/7 usage and heavy Web or logging usage.

MySQL Server was originally designed to work with medium-sized
databases (10-100 million rows, or about 100MB per table) on small
computer systems. Today MySQL Server handles terabyte-sized databases,
but the code can also be compiled in a reduced version suitable for
hand-held and embedded devices. The compact design of the MySQL server
makes development in both directions possible without any conflicts in
the source tree.

Currently, we are not targeting real-time support, although MySQL
replication capabilities offer significant functionality.

MySQL supports high-availability database clustering using the *Note
`NDBCLUSTER': mysql-cluster. storage engine. See *Note mysql-cluster::.

XML support is to be implemented in a future version of the database
server.

File: manual.info, Node: standards, Next: sql-mode, Prev: compatibility, Up: compatibility

2.8.1 What Standards MySQL Follows
----------------------------------

Our aim is to support the full ANSI/ISO SQL standard, but without
making concessions to speed and quality of the code.

ODBC levels 0 to 3.51.

File: manual.info, Node: sql-mode, Next: ansi-mode, Prev: standards, Up: compatibility

2.8.2 Selecting SQL Modes
-------------------------

The MySQL server can operate in different SQL modes, and can apply
these modes differentially for different clients. This capability
enables each application to tailor the server's operating mode to its
own requirements.

SQL modes control aspects of server operation such as what SQL syntax
MySQL should support and what kind of data validation checks it should
perform. This makes it easier to use MySQL in different environments
and to use MySQL together with other database servers.

You can set the default SQL mode by starting *Note `mysqld': mysqld.
with the `--sql-mode="MODE_VALUE"' option. You can also change the mode
at runtime by setting the `sql_mode' system variable with a *Note `SET
[GLOBAL|SESSION] sql_mode='MODE_VALUE'': set-option. statement.

For more information on setting the SQL mode, see *Note
server-sql-mode::.

File: manual.info, Node: ansi-mode, Next: extensions-to-ansi, Prev: sql-mode, Up: compatibility

2.8.3 Running MySQL in ANSI Mode
--------------------------------

You can tell *Note `mysqld': mysqld. to run in ANSI mode with the
`--ansi' startup option. Running the server in ANSI mode is the same
as starting it with the following options:

--transaction-isolation=SERIALIZABLE --sql-mode=ANSI

You can achieve the same effect at runtime by executing these two
statements:

SET GLOBAL TRANSACTION ISOLATION LEVEL SERIALIZABLE;
SET GLOBAL sql_mode = 'ANSI';

You can see that setting the `sql_mode' system variable to `'ANSI''
enables all SQL mode options that are relevant for ANSI mode as follows:

mysql> SET GLOBAL sql_mode='ANSI';
mysql> SELECT @@global.sql_mode;
-> 'REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI'

Running the server in ANSI mode with `--ansi' is not quite the same as
setting the SQL mode to `'ANSI''. The `--ansi' option affects the SQL
mode and also sets the transaction isolation level. Setting the SQL
mode to `'ANSI'' has no effect on the isolation level.

See *Note server-options::, and *Note sql-mode::.

File: manual.info, Node: extensions-to-ansi, Next: differences-from-ansi, Prev: ansi-mode, Up: compatibility

2.8.4 MySQL Extensions to Standard SQL
--------------------------------------

MySQL Server supports some extensions that you probably won't find in
other SQL DBMSs. Be warned that if you use them, your code won't be
portable to other SQL servers. In some cases, you can write code that
includes MySQL extensions, but is still portable, by using comments of
the following form:

/*! MYSQL-SPECIFIC CODE */

In this case, MySQL Server parses and executes the code within the
comment as it would any other SQL statement, but other SQL servers will
ignore the extensions. For example, MySQL Server recognizes the
`STRAIGHT_JOIN' keyword in the following statement, but other servers
will not:

SELECT /*! STRAIGHT_JOIN */ col1 FROM table1,table2 WHERE ...

If you add a version number after the ``!'' character, the syntax within
the comment is executed only if the MySQL version is greater than or
equal to the specified version number. The `TEMPORARY' keyword in the
following comment is executed only by servers from MySQL 3.23.02 or
higher:

CREATE /*!32302 TEMPORARY */ TABLE t (a INT);

The following descriptions list MySQL extensions, organized by category.

* Organization of data on disk

MySQL Server maps each database to a directory under the MySQL
data directory, and maps tables within a database to file names in
the database directory. This has a few implications:

* Database and table names are case sensitive in MySQL Server
on operating systems that have case-sensitive file names
(such as most Unix systems). See *Note
identifier-case-sensitivity::.

* You can use standard system commands to back up, rename,
move, delete, and copy tables that are managed by the
`MyISAM' storage engine. For example, it is possible to
rename a `MyISAM' table by renaming the `.MYD', `.MYI', and
`.frm' files to which the table corresponds. (Nevertheless, it
is preferable to use *Note `RENAME TABLE': rename-table. or
`ALTER TABLE ... RENAME' and let the server rename the
files.)

Database and table names cannot contain path name separator
characters (``/'', ``\'').

* General language syntax

* By default, strings can be enclosed by either ``"'' or ``''',
not just by ``'''. (If the `ANSI_QUOTES' SQL mode is enabled,
strings can be enclosed only by ``''' and the server
interprets strings enclosed by ``"'' as identifiers.)

* ``\'' is the escape character in strings.

* In SQL statements, you can access tables from different
databases with the DB_NAME.TBL_NAME syntax. Some SQL servers
provide the same functionality but call this `User space'.
MySQL Server doesn't support tablespaces such as used in
statements like this: `CREATE TABLE ralph.my_table ... IN
my_tablespace'.

* SQL statement syntax

* The *Note `ANALYZE TABLE': analyze-table, *Note `CHECK
TABLE': check-table, *Note `OPTIMIZE TABLE': optimize-table,
and *Note `REPAIR TABLE': repair-table. statements.

* The *Note `CREATE DATABASE': create-database, *Note `DROP
DATABASE': drop-database, and *Note `ALTER DATABASE':
alter-database. statements. See *Note create-database::,
*Note drop-database::, and *Note alter-database::.

* The *Note `DO': do. statement.

* *Note `EXPLAIN SELECT': explain. to obtain a description of
how tables are processed by the query optimizer.

* The *Note `FLUSH': flush. and *Note `RESET': reset.
statements.

* The *Note `SET': set-option. statement. See *Note
set-option::.

* The *Note `SHOW': show. statement. See *Note show::. The
information produced by many of the MySQL-specific *Note
`SHOW': show. statements can be obtained in more standard
fashion by using *Note `SELECT': select. to query
`INFORMATION_SCHEMA'. See *Note information-schema::.

* Use of *Note `LOAD DATA INFILE': load-data. In many cases,
this syntax is compatible with Oracle's *Note `LOAD DATA
INFILE': load-data. See *Note load-data::.

* Use of *Note `RENAME TABLE': rename-table. See *Note
rename-table::.

* Use of *Note `REPLACE': replace. instead of *Note `DELETE':
delete. plus *Note `INSERT': insert. See *Note replace::.

* Use of `CHANGE COL_NAME', `DROP COL_NAME', or *Note `DROP
INDEX': drop-index, `IGNORE' or `RENAME' in *Note `ALTER
TABLE': alter-table. statements. Use of multiple `ADD',
`ALTER', `DROP', or `CHANGE' clauses in an *Note `ALTER
TABLE': alter-table. statement. See *Note alter-table::.

* Use of index names, indexes on a prefix of a column, and use
of `INDEX' or `KEY' in *Note `CREATE TABLE': create-table.
statements. See *Note create-table::.

* Use of `TEMPORARY' or `IF NOT EXISTS' with *Note `CREATE
TABLE': create-table.

* Use of `IF EXISTS' with *Note `DROP TABLE': drop-table. and
*Note `DROP DATABASE': drop-database.

* The capability of dropping multiple tables with a single
*Note `DROP TABLE': drop-table. statement.

* The `ORDER BY' and `LIMIT' clauses of the *Note `UPDATE':
update. and *Note `DELETE': delete. statements.

* `INSERT INTO TBL_NAME SET COL_NAME = ...' syntax.

* The `DELAYED' clause of the *Note `INSERT': insert. and *Note
`REPLACE': replace. statements.

* The `LOW_PRIORITY' clause of the *Note `INSERT': insert,
*Note `REPLACE': replace, *Note `DELETE': delete, and *Note
`UPDATE': update. statements.

* Use of `INTO OUTFILE' or `INTO DUMPFILE' in *Note `SELECT':
select. statements. See *Note select::.

* Options such as `STRAIGHT_JOIN' or `SQL_SMALL_RESULT' in
*Note `SELECT': select. statements.

* You don't need to name all selected columns in the `GROUP BY'
clause. This gives better performance for some very specific,
but quite normal queries. See *Note
group-by-functions-and-modifiers::.

* You can specify `ASC' and `DESC' with `GROUP BY', not just
with `ORDER BY'.

* The ability to set variables in a statement with the `:='
assignment operator:

mysql> SELECT @a:=SUM(total),@b:=COUNT(*),@a/@b AS avg
-> FROM test_table;
mysql> SELECT @t1:=(@t2:=1)+@t3:=4,@t1,@t2,@t3;

* Data types

* The *Note `MEDIUMINT': numeric-types, *Note `SET': set, and
*Note `ENUM': enum. data types, and the various *Note `BLOB':
blob. and *Note `TEXT': blob. data types.

* The `AUTO_INCREMENT', `BINARY', `NULL', `UNSIGNED', and
`ZEROFILL' data type attributes.

* Functions and operators

* To make it easier for users who migrate from other SQL
environments, MySQL Server supports aliases for many
functions. For example, all string functions support both
standard SQL syntax and ODBC syntax.

* MySQL Server understands the `||' and `&&' operators to mean
logical OR and AND, as in the C programming language. In
MySQL Server, `||' and `OR' are synonyms, as are `&&' and
`AND'. Because of this nice syntax, MySQL Server doesn't
support the standard SQL `||' operator for string
concatenation; use `CONCAT()' instead. Because `CONCAT()'
takes any number of arguments, it is easy to convert use of
the `||' operator to MySQL Server.

* Use of `COUNT(DISTINCT VALUE_LIST)' where VALUE_LIST has more
than one element.

* String comparisons are case-insensitive by default, with sort
ordering determined by the collation of the current character
set, which is `latin1' (cp1252 West European) by default. If
you don't like this, you should declare your columns with the
`BINARY' attribute or use the `BINARY' cast, which causes
comparisons to be done using the underlying character code
values rather then a lexical ordering.

* The `%' operator is a synonym for `MOD()'. That is, `N % M'
is equivalent to `MOD(N,M)'. `%' is supported for C
programmers and for compatibility with PostgreSQL.

* The `=', `<>', `<=', `<', `>=', `>', `<<', `>>', `<=>', `AND',
`OR', or `LIKE' operators may be used in expressions in the
output column list (to the left of the `FROM') in *Note
`SELECT': select. statements. For example:

mysql> SELECT col1=1 AND col2=2 FROM my_table;

* The `LAST_INSERT_ID()' function returns the most recent
`AUTO_INCREMENT' value. See *Note information-functions::.

* `LIKE' is permitted on numeric values.

* The `REGEXP' and `NOT REGEXP' extended regular expression
operators.

* `CONCAT()' or `CHAR()' with one argument or more than two
arguments. (In MySQL Server, these functions can take a
variable number of arguments.)

* The `BIT_COUNT()', `CASE', `ELT()', `FROM_DAYS()', `FORMAT()',
`IF()', `PASSWORD()', `ENCRYPT()', `MD5()', `ENCODE()',
`DECODE()', `PERIOD_ADD()', `PERIOD_DIFF()', `TO_DAYS()', and
`WEEKDAY()' functions.

* Use of `TRIM()' to trim substrings. Standard SQL supports
removal of single characters only.

* The `GROUP BY' functions `STD()', `BIT_OR()', `BIT_AND()',
`BIT_XOR()', and `GROUP_CONCAT()'. See *Note
group-by-functions-and-modifiers::.

File: manual.info, Node: differences-from-ansi, Next: constraints, Prev: extensions-to-ansi, Up: compatibility

2.8.5 MySQL Differences from Standard SQL
-----------------------------------------

* Menu:

* ansi-diff-select-into-table:: `SELECT INTO TABLE'
* ansi-diff-update:: `UPDATE'
* ansi-diff-transactions:: Transactions and Atomic Operations
* ansi-diff-foreign-keys:: Foreign Keys
* ansi-diff-comments:: '`--'' as the Start of a Comment

We try to make MySQL Server follow the ANSI SQL standard and the ODBC
SQL standard, but MySQL Server performs operations differently in some
cases:

* For *Note `VARCHAR': char. columns, trailing spaces are removed
when the value is stored. (This is fixed in MySQL 5.0.3). See
*Note bugs::.

* In some cases, *Note `CHAR': char. columns are silently converted
to *Note `VARCHAR': char. columns when you define a table or alter
its structure. (This no longer occurs as of MySQL 5.0.3). See
*Note silent-column-changes::.

* There are several differences between the MySQL and standard SQL
privilege systems. For example, in MySQL, privileges for a table
are not automatically revoked when you delete a table. You must
explicitly issue a *Note `REVOKE': revoke. statement to revoke
privileges for a table. For more information, see *Note revoke::.

* The `CAST()' function does not support cast to *Note `REAL':
numeric-types. or *Note `BIGINT': numeric-types. See *Note
cast-functions::.

* Standard SQL requires that a `HAVING' clause in a *Note `SELECT':
select. statement be able to refer to columns in the `GROUP BY'
clause. This cannot be done before MySQL 5.0.2.

File: manual.info, Node: ansi-diff-select-into-table, Next: ansi-diff-update, Prev: differences-from-ansi, Up: differences-from-ansi

2.8.5.1 `SELECT INTO TABLE'
...........................

MySQL Server doesn't support the `SELECT ... INTO TABLE' Sybase SQL
extension. Instead, MySQL Server supports the *Note `INSERT INTO ...
SELECT': insert-select. standard SQL syntax, which is basically the
same thing. See *Note insert-select::. For example:

INSERT INTO tbl_temp2 (fld_id)
SELECT tbl_temp1.fld_order_id
FROM tbl_temp1 WHERE tbl_temp1.fld_order_id > 100;

Alternatively, you can use *Note `SELECT ... INTO OUTFILE': select. or
*Note `CREATE TABLE ... SELECT': create-table.

You can use *Note `SELECT ... INTO': select. with user-defined
variables. The same syntax can also be used inside stored routines
using cursors and local variables. See *Note select-into-statement::.

File: manual.info, Node: ansi-diff-update, Next: ansi-diff-transactions, Prev: ansi-diff-select-into-table, Up: differences-from-ansi

2.8.5.2 `UPDATE'
................

If you access a column from the table to be updated in an expression,
*Note `UPDATE': update. uses the current value of the column. The
second assignment in the following statement sets `col2' to the current
(updated) `col1' value, not the original `col1' value. The result is
that `col1' and `col2' have the same value. This behavior differs from
standard SQL.

UPDATE t1 SET col1 = col1 + 1, col2 = col1;

File: manual.info, Node: ansi-diff-transactions, Next: ansi-diff-foreign-keys, Prev: ansi-diff-update, Up: differences-from-ansi

2.8.5.3 Transactions and Atomic Operations
..........................................

MySQL Server (version 3.23-max and all versions 4.0 and above) supports
transactions with the `InnoDB' and `BDB' transactional storage engines.
`InnoDB' provides _full_ ACID compliance. See *Note storage-engines::.
For information about `InnoDB' differences from standard SQL with
regard to treatment of transaction errors, see *Note
innodb-error-handling::.

The other nontransactional storage engines in MySQL Server (such as
`MyISAM') follow a different paradigm for data integrity called `atomic
operations.' In transactional terms, `MyISAM' tables effectively always
operate in `autocommit = 1' mode. Atomic operations often offer
comparable integrity with higher performance.

Because MySQL Server supports both paradigms, you can decide whether
your applications are best served by the speed of atomic operations or
the use of transactional features. This choice can be made on a
per-table basis.

As noted, the tradeoff for transactional versus nontransactional
storage engines lies mostly in performance. Transactional tables have
significantly higher memory and disk space requirements, and more CPU
overhead. On the other hand, transactional storage engines such as
`InnoDB' also offer many significant features. MySQL Server's modular
design enables the concurrent use of different storage engines to suit
different requirements and deliver optimum performance in all
situations.

But how do you use the features of MySQL Server to maintain rigorous
integrity even with the nontransactional `MyISAM' tables, and how do
these features compare with the transactional storage engines?

* If your applications are written in a way that is dependent on
being able to call *Note `ROLLBACK': commit. rather than *Note
`COMMIT': commit. in critical situations, transactions are more
convenient. Transactions also ensure that unfinished updates or
corrupting activities are not committed to the database; the
server is given the opportunity to do an automatic rollback and
your database is saved.

If you use nontransactional tables, MySQL Server in almost all
cases enables you to resolve potential problems by including
simple checks before updates and by running simple scripts that
check the databases for inconsistencies and automatically repair
or warn if such an inconsistency occurs. You can normally fix
tables perfectly with no data integrity loss just by using the
MySQL log or even adding one extra log.

* More often than not, critical transactional updates can be
rewritten to be atomic. Generally speaking, all integrity problems
that transactions solve can be done with *Note `LOCK TABLES':
lock-tables. or atomic updates, ensuring that there are no
automatic aborts from the server, which is a common problem with
transactional database systems.

* To be safe with MySQL Server, regardless of whether you use
transactional tables, you only need to have backups and have
binary logging turned on. When that is true, you can recover from
any situation that you could with any other transactional database
system. It is always good to have backups, regardless of which
database system you use.

The transactional paradigm has its advantages and disadvantages. Many
users and application developers depend on the ease with which they can
code around problems where an abort appears to be necessary, or is
necessary. However, even if you are new to the atomic operations
paradigm, or more familiar with transactions, do consider the speed
benefit that nontransactional tables can offer on the order of three to
five times the speed of the fastest and most optimally tuned
transactional tables.

In situations where integrity is of highest importance, MySQL Server
offers transaction-level reliability and integrity even for
nontransactional tables. If you lock tables with *Note `LOCK TABLES':
lock-tables, all updates stall until integrity checks are made. If you
obtain a `READ LOCAL' lock (as opposed to a write lock) for a table
that enables concurrent inserts at the end of the table, reads are
permitted, as are inserts by other clients. The newly inserted records
are not be seen by the client that has the read lock until it releases
the lock. With *Note `INSERT DELAYED': insert-delayed, you can write
inserts that go into a local queue until the locks are released,
without having the client wait for the insert to complete. See *Note
concurrent-inserts::, and *Note insert-delayed::.

`Atomic,' in the sense that we mean it, is nothing magical. It only
means that you can be sure that while each specific update is running,
no other user can interfere with it, and there can never be an
automatic rollback (which can happen with transactional tables if you
are not very careful). MySQL Server also guarantees that there are no
dirty reads.

Following are some techniques for working with nontransactional tables:

* Loops that need transactions normally can be coded with the help
of *Note `LOCK TABLES': lock-tables, and you don't need cursors to
update records on the fly.

* To avoid using *Note `ROLLBACK': commit, you can employ the
following strategy:

1. Use *Note `LOCK TABLES': lock-tables. to lock all the tables
you want to access.

2. Test the conditions that must be true before performing the
update.

3. Update if the conditions are satisfied.

4. Use *Note `UNLOCK TABLES': lock-tables. to release your locks.

This is usually a much faster method than using transactions with
possible rollbacks, although not always. The only situation this
solution doesn't handle is when someone kills the threads in the
middle of an update. In that case, all locks are released but some
of the updates may not have been executed.

* You can also use functions to update records in a single
operation. You can get a very efficient application by using the
following techniques:

* Modify columns relative to their current value.

* Update only those columns that actually have changed.

For example, when we are updating customer information, we update
only the customer data that has changed and test only that none of
the changed data, or data that depends on the changed data, has
changed compared to the original row. The test for changed data is
done with the `WHERE' clause in the *Note `UPDATE': update.
statement. If the record wasn't updated, we give the client a
message: `Some of the data you have changed has been changed by
another user.' Then we show the old row versus the new row in a
window so that the user can decide which version of the customer
record to use.

This gives us something that is similar to column locking but is
actually even better because we only update some of the columns,
using values that are relative to their current values. This means
that typical *Note `UPDATE': update. statements look something
like these:

UPDATE tablename SET pay_back=pay_back+125;

UPDATE customer
SET
customer_date='current_date',
address='new address',
phone='new phone',
money_owed_to_us=money_owed_to_us-125
WHERE
customer_id=id AND address='old address' AND phone='old phone';

This is very efficient and works even if another client has
changed the values in the `pay_back' or `money_owed_to_us' columns.

* In many cases, users have wanted *Note `LOCK TABLES': lock-tables.
or *Note `ROLLBACK': commit. for the purpose of managing unique
identifiers. This can be handled much more efficiently without
locking or rolling back by using an `AUTO_INCREMENT' column and
either the `LAST_INSERT_ID()' SQL function or the *Note
`mysql_insert_id()': mysql-insert-id. C API function. See *Note
information-functions::, and *Note mysql-insert-id::.

You can generally code around the need for row-level locking. Some
situations really do need it, and `InnoDB' tables support row-level
locking. Otherwise, with `MyISAM' tables, you can use a flag
column in the table and do something like the following:

UPDATE TBL_NAME SET row_flag=1 WHERE id=ID;

MySQL returns `1' for the number of affected rows if the row was
found and `row_flag' wasn't `1' in the original row. You can think
of this as though MySQL Server changed the preceding statement to:

UPDATE TBL_NAME SET row_flag=1 WHERE id=ID AND row_flag <> 1;

File: manual.info, Node: ansi-diff-foreign-keys, Next: ansi-diff-comments, Prev: ansi-diff-transactions, Up: differences-from-ansi

2.8.5.4 Foreign Keys
....................

The `InnoDB' storage engine supports checking of foreign key
constraints, including `CASCADE', `ON DELETE', and `ON UPDATE'. See
*Note innodb-foreign-key-constraints::.

For storage engines other than `InnoDB', MySQL Server parses the
`FOREIGN KEY' syntax in *Note `CREATE TABLE': create-table. statements,
but does not use or store it. In the future, the implementation will be
extended to store this information in the table specification file so
that it may be retrieved by *Note `mysqldump': mysqldump. and ODBC. At
a later stage, foreign key constraints will be implemented for `MyISAM'
tables as well.

Foreign key enforcement offers several benefits to database developers:

* Assuming proper design of the relationships, foreign key
constraints make it more difficult for a programmer to introduce
an inconsistency into the database.

* Centralized checking of constraints by the database server makes
it unnecessary to perform these checks on the application side.
This eliminates the possibility that different applications may
not all check the constraints in the same way.

* Using cascading updates and deletes can simplify the application
code.

* Properly designed foreign key rules aid in documenting
relationships between tables.

Do keep in mind that these benefits come at the cost of additional
overhead for the database server to perform the necessary checks.
Additional checking by the server affects performance, which for some
applications may be sufficiently undesirable as to be avoided if
possible. (Some major commercial applications have coded the foreign
key logic at the application level for this reason.)

MySQL gives database developers the choice of which approach to use. If
you don't need foreign keys and want to avoid the overhead associated
with enforcing referential integrity, you can choose another storage
engine instead, such as `MyISAM'. (For example, the `MyISAM' storage
engine offers very fast performance for applications that perform only
*Note `INSERT': insert. and *Note `SELECT': select. operations. In this
case, the table has no holes in the middle and the inserts can be
performed concurrently with retrievals. See *Note concurrent-inserts::.)

If you choose not to take advantage of referential integrity checks,
keep the following considerations in mind:

* In the absence of server-side foreign key relationship checking,
the application itself must handle relationship issues. For
example, it must take care to insert rows into tables in the
proper order, and to avoid creating orphaned child records. It
must also be able to recover from errors that occur in the middle
of multiple-record insert operations.

* If `ON DELETE' is the only referential integrity capability an
application needs, you can achieve a similar effect as of MySQL
Server 4.0 by using multiple-table *Note `DELETE': delete.
statements to delete rows from many tables with a single
statement. See *Note delete::.

* A workaround for the lack of `ON DELETE' is to add the appropriate
*Note `DELETE': delete. statements to your application when you
delete records from a table that has a foreign key. In practice,
this is often as quick as using foreign keys and is more portable.

Be aware that the use of foreign keys can sometimes lead to problems:

* Foreign key support addresses many referential integrity issues,
but it is still necessary to design key relationships carefully to
avoid circular rules or incorrect combinations of cascading
deletes.

* It is not uncommon for a DBA to create a topology of relationships
that makes it difficult to restore individual tables from a
backup. (MySQL alleviates this difficulty by enabling you to
temporarily disable foreign key checks when reloading a table that
depends on other tables. See *Note
innodb-foreign-key-constraints::. As of MySQL 4.1.1, *Note
`mysqldump': mysqldump. generates dump files that take advantage
of this capability automatically when they are reloaded.)

Foreign keys in SQL are used to check and enforce referential
integrity, not to join tables. If you want to get results from multiple
tables from a *Note `SELECT': select. statement, you do this by
performing a join between them:

SELECT * FROM t1 INNER JOIN t2 ON t1.id = t2.id;

See *Note join::, and *Note example-foreign-keys::.

The `FOREIGN KEY' syntax without `ON DELETE ...' is often used by ODBC
applications to produce automatic `WHERE' clauses.

File: manual.info, Node: ansi-diff-comments, Prev: ansi-diff-foreign-keys, Up: differences-from-ansi

2.8.5.5 '`--'' as the Start of a Comment
........................................

Standard SQL uses the C syntax `/* this is a comment */' for comments,
and MySQL Server supports this syntax as well. MySQL also support
extensions to this syntax that enable MySQL-specific SQL to be embedded
in the comment, as described in *Note comments::.

Standard SQL uses ``--'' as a start-comment sequence. MySQL Server uses
``#'' as the start comment character. MySQL Server 3.23.3 and up also
supports a variant of the ``--'' comment style. That is, the ``--''
start-comment sequence must be followed by a space (or by a control
character such as a newline). The space is required to prevent problems
with automatically generated SQL queries that use constructs such as
the following, where we automatically insert the value of the payment
for `payment':

UPDATE account SET credit=credit-payment

Consider about what happens if `payment' has a negative value such as
`-1':

UPDATE account SET credit=credit--1

`credit--1' is a legal expression in SQL, but ``--'' is interpreted as
the start of a comment, part of the expression is discarded. The result
is a statement that has a completely different meaning than intended:

UPDATE account SET credit=credit

The statement produces no change in value at all. This illustrates that
permitting comments to start with ``--'' can have serious consequences.

Using our implementation requires a space following the ``--'' for it
to be recognized as a start-comment sequence in MySQL Server 3.23.3 and
newer. Therefore, `credit--1' is safe to use.

Another safe feature is that the *Note `mysql': mysql. command-line
client ignores lines that start with ``--''.

The following information is relevant only if you are running a MySQL
version earlier than 3.23.3:

If you have an SQL script in a text file that contains ``--'' comments,
you should use the *Note `replace': replace-utility. utility as follows
to convert the comments to use ``#'' characters before executing the
script:

shell> replace " --" " #" < text-file-with-funny-comments.sql \
| mysql DB_NAME

That is safer than executing the script in the usual way:

shell> mysql DB_NAME < text-file-with-funny-comments.sql

You can also edit the script file `in place' to change the ``--''
comments to ``#'' comments:

shell> replace " --" " #" -- text-file-with-funny-comments.sql

Change them back with this command:

shell> replace " #" " --" -- text-file-with-funny-comments.sql

See *Note replace-utility::.

File: manual.info, Node: constraints, Prev: differences-from-ansi, Up: compatibility

2.8.6 How MySQL Deals with Constraints
--------------------------------------

* Menu:

* constraint-primary-key:: `PRIMARY KEY' and `UNIQUE' Index Constraints
* constraint-invalid-data:: Constraints on Invalid Data
* constraint-enum:: `ENUM' and `SET' Constraints

MySQL enables you to work both with transactional tables that permit
rollback and with nontransactional tables that do not. Because of
this, constraint handling is a bit different in MySQL than in other
DBMSs. We must handle the case when you have inserted or updated a lot
of rows in a nontransactional table for which changes cannot be rolled
back when an error occurs.

The basic philosophy is that MySQL Server tries to produce an error for
anything that it can detect while parsing a statement to be executed,
and tries to recover from any errors that occur while executing the
statement. We do this in most cases, but not yet for all.

The options MySQL has when an error occurs are to stop the statement in
the middle or to recover as well as possible from the problem and
continue. By default, the server follows the latter course. This means,
for example, that the server may coerce illegal values to the closest
legal values.

Beginning with MySQL 5.0.2, several SQL mode options are available to
provide greater control over handling of bad data values and whether to
continue statement execution or abort when errors occur. Using these
options, you can configure MySQL Server to act in a more traditional
fashion that is like other DBMSs that reject improper input. The SQL
mode can be set globally at server startup to affect all clients.
Individual clients can set the SQL mode at runtime, which enables each
client to select the behavior most appropriate for its requirements.
See *Note server-sql-mode::.

The following sections describe how MySQL Server handles different
types of constraints.

File: manual.info, Node: constraint-primary-key, Next: constraint-invalid-data, Prev: constraints, Up: constraints

2.8.6.1 `PRIMARY KEY' and `UNIQUE' Index Constraints
....................................................

Normally, errors occurs for data-change statements (such as *Note
`INSERT': insert. or *Note `UPDATE': update.) that would violate
primary-key, unique-key, or foreign-key constraints. If you are using a
transactional storage engine such as `InnoDB', MySQL automatically
rolls back the statement. If you are using a nontransactional storage
engine, MySQL stops processing the statement at the row for which the
error occurred and leaves any remaining rows unprocessed.

MySQL supports an `IGNORE' keyword for *Note `INSERT': insert, *Note
`UPDATE': update, and so forth. If you use it, MySQL ignores
primary-key or unique-key violations and continues processing with the
next row. See the section for the statement that you are using (*Note
insert::, *Note update::, and so forth).

You can get information about the number of rows actually inserted or
updated with the *Note `mysql_info()': mysql-info. C API function. You
can also use the *Note `SHOW WARNINGS': show-warnings. statement. See
*Note mysql-info::, and *Note show-warnings::.

Currently, only `InnoDB' tables support foreign keys. See *Note
innodb-foreign-key-constraints::.

File: manual.info, Node: constraint-invalid-data, Next: constraint-enum, Prev: constraint-primary-key, Up: constraints

2.8.6.2 Constraints on Invalid Data
...................................

Before MySQL 5.0.2, MySQL is forgiving of illegal or improper data
values and coerces them to legal values for data entry. In MySQL 5.0.2
and up, that remains the default behavior, but you can change the
server SQL mode to select more traditional treatment of bad values such
that the server rejects them and aborts the statement in which they
occur. *Note server-sql-mode::.

This section describes the default (forgiving) behavior of MySQL, as
well as the strict SQL mode and how it differs.

If you are not using strict mode, then whenever you insert an
`incorrect' value into a column, such as a `NULL' into a `NOT NULL'
column or a too-large numeric value into a numeric column, MySQL sets
the column to the `best possible value' instead of producing an error:
The following rules describe in more detail how this works:

* If you try to store an out of range value into a numeric column,
MySQL Server instead stores zero, the smallest possible value, or
the largest possible value, whichever is closest to the invalid
value.

* For strings, MySQL stores either the empty string or as much of
the string as can be stored in the column.

* If you try to store a string that doesn't start with a number into
a numeric column, MySQL Server stores 0.

* Invalid values for *Note `ENUM': enum. and *Note `SET': set.
columns are handled as described in *Note constraint-enum::.

* MySQL enables you to store certain incorrect date values into
*Note `DATE': datetime. and *Note `DATETIME': datetime. columns
(such as `'2000-02-31'' or `'2000-02-00''). The idea is that it is
not the job of the SQL server to validate dates. If MySQL can
store a date value and retrieve exactly the same value, MySQL
stores it as given. If the date is totally wrong (outside the
server's ability to store it), the special `zero' date value
`'0000-00-00'' is stored in the column instead.

* If you try to store `NULL' into a column that doesn't take `NULL'
values, an error occurs for single-row *Note `INSERT': insert.
statements. For multiple-row *Note `INSERT': insert. statements
or for *Note `INSERT INTO ... SELECT': insert-select. statements,
MySQL Server stores the implicit default value for the column data
type. In general, this is `0' for numeric types, the empty string
(`''') for string types, and the `zero' value for date and time
types. Implicit default values are discussed in *Note
data-type-defaults::.

* If an *Note `INSERT': insert. statement specifies no value for a
column, MySQL inserts its default value if the column definition
includes an explicit `DEFAULT' clause. If the definition has no
such `DEFAULT' clause, MySQL inserts the implicit default value
for the column data type.

The reason for using the preceding rules in nonstrict mode is that we
can't check these conditions until the statement has begun executing.
We can't just roll back if we encounter a problem after updating a few
rows, because the storage engine may not support rollback. The option
of terminating the statement is not that good; in this case, the update
would be `half done,' which is probably the worst possible scenario. In
this case, it is better to `do the best you can' and then continue as
if nothing happened.

In MySQL 5.0.2 and up, you can select stricter treatment of input
values by using the `STRICT_TRANS_TABLES' or `STRICT_ALL_TABLES' SQL
modes:

SET sql_mode = 'STRICT_TRANS_TABLES';
SET sql_mode = 'STRICT_ALL_TABLES';

`STRICT_TRANS_TABLES' enables strict mode for transactional storage
engines, and also to some extent for nontransactional engines. It works
like this:

* For transactional storage engines, bad data values occurring
anywhere in a statement cause the statement to abort and roll back.

* For nontransactional storage engines, a statement aborts if the
error occurs in the first row to be inserted or updated. (When the
error occurs in the first row, the statement can be aborted to
leave the table unchanged, just as for a transactional table.)
Errors in rows after the first do not abort the statement, because
the table has already been changed by the first row. Instead, bad
data values are adjusted and result in warnings rather than
errors. In other words, with `STRICT_TRANS_TABLES', a wrong value
causes MySQL to roll back all updates done so far, if that can be
done without changing the table. But once the table has been
changed, further errors result in adjustments and warnings.

For even stricter checking, enable `STRICT_ALL_TABLES'. This is the
same as `STRICT_TRANS_TABLES' except that for nontransactional storage
engines, errors abort the statement even for bad data in rows following
the first row. This means that if an error occurs partway through a
multiple-row insert or update for a nontransactional table, a partial
update results. Earlier rows are inserted or updated, but those from
the point of the error on are not. To avoid this for nontransactional
tables, either use single-row statements or else use
`STRICT_TRANS_TABLES' if conversion warnings rather than errors are
acceptable. To avoid problems in the first place, do not use MySQL to
check column content. It is safest (and often faster) to let the
application ensure that it passes only legal values to the database.

With either of the strict mode options, you can cause errors to be
treated as warnings by using *Note `INSERT IGNORE': insert. or `UPDATE
IGNORE' rather than *Note `INSERT': insert. or *Note `UPDATE': update.
without `IGNORE'.

File: manual.info, Node: constraint-enum, Prev: constraint-invalid-data, Up: constraints

2.8.6.3 `ENUM' and `SET' Constraints
....................................

*Note `ENUM': enum. and *Note `SET': set. columns provide an efficient
way to define columns that can contain only a given set of values. See
*Note enum::, and *Note set::. However, before MySQL 5.0.2, *Note
`ENUM': enum. and *Note `SET': set. columns do not provide true
constraints on entry of invalid data:

* *Note `ENUM': enum. columns always have a default value. If you
specify no default value, then it is `NULL' for columns that can
have `NULL', otherwise it is the first enumeration value in the
column definition.

* If you insert an incorrect value into an *Note `ENUM': enum.
column or if you force a value into an *Note `ENUM': enum. column
with `IGNORE', it is set to the reserved enumeration value of `0',
which is displayed as an empty string in string context.

* If you insert an incorrect value into a *Note `SET': set. column,
the incorrect value is ignored. For example, if the column can
contain the values `'a'', `'b'', and `'c'', an attempt to assign
`'a,x,b,y'' results in a value of `'a,b''.

As of MySQL 5.0.2, you can configure the server to use strict SQL mode.
See *Note server-sql-mode::. With strict mode enabled, the definition
of a *Note `ENUM': enum. or *Note `SET': set. column does act as a
constraint on values entered into the column. An error occurs for
values that do not satisfy these conditions:

* An *Note `ENUM': enum. value must be one of those listed in the
column definition, or the internal numeric equivalent thereof. The
value cannot be the error value (that is, 0 or the empty string).
For a column defined as *Note `ENUM('a','b','c')': enum, values
such as `''', `'d'', or `'ax'' are illegal and are rejected.

* A *Note `SET': set. value must be the empty string or a value
consisting only of the values listed in the column definition
separated by commas. For a column defined as *Note
`SET('a','b','c')': set, values such as `'d'' or `'a,b,c,d'' are
illegal and are rejected.

Errors for invalid values can be suppressed in strict mode if you use
*Note `INSERT IGNORE': insert. or `UPDATE IGNORE'. In this case, a
warning is generated rather than an error. For *Note `ENUM': enum, the
value is inserted as the error member (`0'). For *Note `SET': set, the
value is inserted as given except that any invalid substrings are
deleted. For example, `'a,x,b,y'' results in a value of `'a,b''.

File: manual.info, Node: credits, Prev: compatibility, Up: introduction

2.9 Credits
===========

* Menu:

* contributors:: Contributors to MySQL
* documenters-translators:: Documenters and translators
* packages:: Packages that support MySQL
* tools-used-to-create-mysql:: Tools that were used to create MySQL
* supporters:: Supporters of MySQL

The following sections list developers, contributors, and supporters
that have helped to make MySQL what it is today.

File: manual.info, Node: contributors, Next: documenters-translators, Prev: credits, Up: credits

2.9.1 Contributors to MySQL
---------------------------

Although Oracle Corporation and/or its affiliates own all copyrights in
the `MySQL server' and the `MySQL manual', we wish to recognize those
who have made contributions of one kind or another to the `MySQL
distribution'. Contributors are listed here, in somewhat random order:

* Gianmassimo Vigazzola <qwerg@mbox.vol.it> or <qwerg@tin.it>

The initial port to Win32/NT.

* Per Eric Olsson

For constructive criticism and real testing of the dynamic record
format.

* Irena Pancirov <irena@mail.yacc.it>

Win32 port with Borland compiler. `mysqlshutdown.exe' and
`mysqlwatch.exe'.

* David J. Hughes

For the effort to make a shareware SQL database. At TcX, the
predecessor of MySQL AB, we started with `mSQL', but found that it
couldn't satisfy our purposes so instead we wrote an SQL interface
to our application builder Unireg. *Note `mysqladmin': mysqladmin.
and *Note `mysql': mysql. client are programs that were largely
influenced by their `mSQL' counterparts. We have put a lot of
effort into making the MySQL syntax a superset of `mSQL'. Many of
the API's ideas are borrowed from `mSQL' to make it easy to port
free `mSQL' programs to the MySQL API. The MySQL software doesn't
contain any code from `mSQL'. Two files in the distribution
(`client/insert_test.c' and `client/select_test.c') are based on
the corresponding (noncopyrighted) files in the `mSQL'
distribution, but are modified as examples showing the changes
necessary to convert code from `mSQL' to MySQL Server. (`mSQL' is
copyrighted David J. Hughes.)

* Patrick Lynch

For helping us acquire http://www.mysql.com/.

* Fred Lindberg

For setting up qmail to handle the MySQL mailing list and for the
incredible help we got in managing the MySQL mailing lists.

* Igor Romanenko <igor@frog.kiev.ua>

*Note `mysqldump': mysqldump. (previously `msqldump', but ported
and enhanced by Monty).

* Yuri Dario

For keeping up and extending the MySQL OS/2 port.

* Tim Bunce

Author of *Note `mysqlhotcopy': mysqlhotcopy.

* Zarko Mocnik <zarko.mocnik@dem.si>

Sorting for Slovenian language.

* "TAMITO" <tommy@valley.ne.jp>

The `_MB' character set macros and the ujis and sjis character
sets.

* Joshua Chamas <joshua@chamas.com>

Base for concurrent insert, extended date syntax, debugging on NT,
and answering on the MySQL mailing list.

* Yves Carlier <Yves.Carlier@rug.ac.be>

*Note `mysqlaccess': mysqlaccess, a program to show the access
rights for a user.

* Rhys Jones <rhys@wales.com> (And GWE Technologies Limited)

For one of the early JDBC drivers.

* Dr Xiaokun Kelvin ZHU <X.Zhu@brad.ac.uk>

Further development of one of the early JDBC drivers and other
MySQL-related Java tools.

* James Cooper <pixel@organic.com>

For setting up a searchable mailing list archive at his site.

* Rick Mehalick <Rick_Mehalick@i-o.com>

For `xmysql', a graphical X client for MySQL Server.

* Doug Sisk <sisk@wix.com>

For providing RPM packages of MySQL for Red Hat Linux.

* Diemand Alexander V. <axeld@vial.ethz.ch>

For providing RPM packages of MySQL for Red Hat Linux-Alpha.

* Antoni Pamies Olive <toni@readysoft.es>

For providing RPM versions of a lot of MySQL clients for Intel and
SPARC.

* Jay Bloodworth <jay@pathways.sde.state.sc.us>

For providing RPM versions for MySQL 3.21.

* David Sacerdote <davids@secnet.com>

Ideas for secure checking of DNS host names.

* Wei-Jou Chen <jou@nematic.ieo.nctu.edu.tw>

Some support for Chinese(BIG5) characters.

* Wei He <hewei@mail.ied.ac.cn>

A lot of functionality for the Chinese(GBK) character set.

* Jan Pazdziora <adelton@fi.muni.cz>

Czech sorting order.

* Zeev Suraski <bourbon@netvision.net.il>

`FROM_UNIXTIME()' time formatting, `ENCRYPT()' functions, and
`bison' advisor. Active mailing list member.

* Luuk de Boer <luuk@wxs.nl>

Ported (and extended) the benchmark suite to `DBI'/`DBD'. Have
been of great help with `crash-me' and running benchmarks. Some
new date functions. The *Note `mysql_setpermission':
mysql-setpermission. script.

* Alexis Mikhailov <root@medinf.chuvashia.su>

User-defined functions (UDFs); *Note `CREATE FUNCTION':
create-function. and *Note `DROP FUNCTION': drop-function.

* Andreas F. Bobak <bobak@relog.ch>

The `AGGREGATE' extension to user-defined functions.

* Ross Wakelin <R.Wakelin@march.co.uk>

Help to set up InstallShield for MySQL-Win32.

* Jethro Wright III <jetman@li.net>

The `libmysql.dll' library.

* James Pereria <jpereira@iafrica.com>

Mysqlmanager, a Win32 GUI tool for administering MySQL Servers.

* Curt Sampson <cjs@portal.ca>

Porting of MIT-pthreads to NetBSD/Alpha and NetBSD 1.3/i386.

* Martin Ramsch <m.ramsch@computer.org>

Examples in the MySQL Tutorial.

* Steve Harvey

For making *Note `mysqlaccess': mysqlaccess. more secure.

* Konark IA-64 Centre of Persistent Systems Private Limited

`http://www.pspl.co.in/konark/'. Help with the Win64 port of the
MySQL server.

* Albert Chin-A-Young.

Configure updates for Tru64, large file support and better TCP
wrappers support.

* John Birrell

Emulation of `pthread_mutex()' for OS/2.

* Benjamin Pflugmann

Extended `MERGE' tables to handle `INSERTS'. Active member on the
MySQL mailing lists.

* Jocelyn Fournier

Excellent spotting and reporting innumerable bugs (especially in
the MySQL 4.1 subquery code).

* Marc Liyanage

Maintaining the Mac OS X packages and providing invaluable
feedback on how to create Mac OS X packages.

* Robert Rutherford

Providing invaluable information and feedback about the QNX port.

* Previous developers of NDB Cluster

Lots of people were involved in various ways summer students,
master thesis students, employees. In total more than 100 people
so too many to mention here. Notable name is Ataullah Dabaghi who
up until 1999 contributed around a third of the code base. A
special thanks also to developers of the AXE system which provided
much of the architectural foundations for NDB Cluster with blocks,
signals and crash tracing functionality. Also credit should be
given to those who believed in the ideas enough to allocate of
their budgets for its development from 1992 to present time.

* Google Inc.

We wish to recognize Google Inc. for contributions to the MySQL
distribution: Mark Callaghan's SMP Performance patches and other
patches.

Other contributors, bugfinders, and testers: James H. Thompson,
Maurizio Menghini, Wojciech Tryc, Luca Berra, Zarko Mocnik, Wim Bonis,
Elmar Haneke, <jehamby@lightside>, <psmith@BayNetworks.com>,
<duane@connect.com.au>, Ted Deppner <ted@psyber.com>, Mike Simons,
Jaakko Hyvatti.

And lots of bug report/patches from the folks on the mailing list.

A big tribute goes to those that help us answer questions on the MySQL
mailing lists:

* Daniel Koch <dkoch@amcity.com>

Irix setup.

* Luuk de Boer <luuk@wxs.nl>

Benchmark questions.

* Tim Sailer <tps@users.buoy.com>

`DBD::mysql' questions.

* Boyd Lynn Gerber <gerberb@zenez.com>

SCO-related questions.

* Richard Mehalick <RM186061@shellus.com>

`xmysql'-related questions and basic installation questions.

* Zeev Suraski <bourbon@netvision.net.il>

Apache module configuration questions (log & auth), PHP-related
questions, SQL syntax-related questions and other general
questions.

* Francesc Guasch <frankie@citel.upc.es>

General questions.

* Jonathan J Smith <jsmith@wtp.net>

Questions pertaining to OS-specifics with Linux, SQL syntax, and
other things that might need some work.

* David Sklar <sklar@student.net>

Using MySQL from PHP and Perl.

* Alistair MacDonald <A.MacDonald@uel.ac.uk>

Is flexible and can handle Linux and perhaps HP-UX.

* John Lyon <jlyon@imag.net>

Questions about installing MySQL on Linux systems, using either
`.rpm' files or compiling from source.

* Lorvid Ltd. <lorvid@WOLFENET.com>

Simple billing/license/support/copyright issues.

* Patrick Sherrill <patrick@coconet.com>

ODBC and VisualC++ interface questions.

* Randy Harmon <rjharmon@uptimecomputers.com>

`DBD', Linux, some SQL syntax questions.

File: manual.info, Node: documenters-translators, Next: packages, Prev: contributors, Up: credits

2.9.2 Documenters and translators
---------------------------------

The following people have helped us with writing the MySQL
documentation and translating the documentation or error messages in
MySQL.

* Paul DuBois

Ongoing help with making this manual correct and understandable.
That includes rewriting Monty's and David's attempts at English
into English as other people know it.

* Kim Aldale

Helped to rewrite Monty's and David's early attempts at English
into English.

* Michael J. Miller Jr. <mke@terrapin.turbolift.com>

For the first MySQL manual. And a lot of spelling/language fixes
for the FAQ (that turned into the MySQL manual a long time ago).

* Yan Cailin

First translator of the MySQL Reference Manual into simplified
Chinese in early 2000 on which the Big5 and HK coded
(`http://mysql.hitstar.com/') versions were based. Personal home
page at linuxdb.yeah.net (http://linuxdb.yeah.net).

* Jay Flaherty <fty@mediapulse.com>

Big parts of the Perl `DBI'/`DBD' section in the manual.

* Paul Southworth <pauls@etext.org>, Ray Loyzaga <yar@cs.su.oz.au>

Proof-reading of the Reference Manual.

* Therrien Gilbert <gilbert@ican.net>, Jean-Marc Pouyot
<jmp@scalaire.fr>

French error messages.

* Petr Snajdr, <snajdr@pvt.net>

Czech error messages.

* Jaroslaw Lewandowski <jotel@itnet.com.pl>

Polish error messages.

* Miguel Angel Fernandez Roiz

Spanish error messages.

* Roy-Magne Mo <rmo@www.hivolda.no>

Norwegian error messages and testing of MySQL 3.21.xx.

* Timur I. Bakeyev <root@timur.tatarstan.ru>

Russian error messages.

* <brenno@dewinter.com> & Filippo Grassilli <phil@hyppo.com>

Italian error messages.

* Dirk Munzinger <dirk@trinity.saar.de>

German error messages.

* Billik Stefan <billik@sun.uniag.sk>

Slovak error messages.

* Stefan Saroiu <tzoompy@cs.washington.edu>

Romanian error messages.

* Peter Feher

Hungarian error messages.

* Roberto M. Serqueira

Portuguese error messages.

* Carsten H. Pedersen

Danish error messages.

* Arjen Lentz

Dutch error messages, completing earlier partial translation (also
work on consistency and spelling).

File: manual.info, Node: packages, Next: tools-used-to-create-mysql, Prev: documenters-translators, Up: credits

2.9.3 Packages that support MySQL
---------------------------------

The following is a list of creators/maintainers of some of the most
important API/packages/applications that a lot of people use with MySQL.

We cannot list every possible package here because the list would then
be way to hard to maintain. For other packages, please refer to the
software portal at `http://solutions.mysql.com/software/'.

* Tim Bunce, Alligator Descartes

For the `DBD' (Perl) interface.

* Andreas Koenig <a.koenig@mind.de>

For the Perl interface for MySQL Server.

* Jochen Wiedmann <wiedmann@neckar-alb.de>

For maintaining the Perl `DBD::mysql' module.

* Eugene Chan <eugene@acenet.com.sg>

For porting PHP for MySQL Server.

* Georg Richter

MySQL 4.1 testing and bug hunting. New PHP 5.0 `mysqli' extension
(API) for use with MySQL 4.1 and up.

* Giovanni Maruzzelli <maruzz@matrice.it>

For porting iODBC (Unix ODBC).

* Xavier Leroy <Xavier.Leroy@inria.fr>

The author of LinuxThreads (used by the MySQL Server on Linux).

File: manual.info, Node: tools-used-to-create-mysql, Next: supporters, Prev: packages, Up: credits

2.9.4 Tools that were used to create MySQL
------------------------------------------

The following is a list of some of the tools we have used to create
MySQL. We use this to express our thanks to those that has created them
as without these we could not have made MySQL what it is today.

* Free Software Foundation

From whom we got an excellent compiler (`gcc'), an excellent
debugger (`gdb' and the `libc' library (from which we have borrowed
`strto.c' to get some code working in Linux).

* Free Software Foundation & The XEmacs development team

For a really great editor/environment.

* Julian Seward

Author of `valgrind', an excellent memory checker tool that has
helped us find a lot of otherwise hard to find bugs in MySQL.

* Dorothea Lu"tkehaus and Andreas Zeller

For `DDD' (The Data Display Debugger) which is an excellent
graphical front end to `gdb').

File: manual.info, Node: supporters, Prev: tools-used-to-create-mysql, Up: credits

2.9.5 Supporters of MySQL
-------------------------

Although Oracle Corporation and/or its affiliates own all copyrights in
the `MySQL server' and the `MySQL manual', we wish to recognize the
following companies, which helped us finance the development of the
`MySQL server', such as by paying us for developing a new feature or
giving us hardware for development of the `MySQL server'.

* VA Linux / Andover.net

Funded replication.

* NuSphere

Editing of the MySQL manual.

* Stork Design studio

The MySQL Web site in use between 1998-2000.

* Intel

Contributed to development on Windows and Linux platforms.

* Compaq

Contributed to Development on Linux/Alpha.

* SWSoft

Development on the embedded *Note `mysqld': mysqld. version.

* FutureQuest

The `--skip-show-database' option.

File: manual.info, Node: installing, Next: tutorial, Prev: introduction, Up: Top

3 Installing and Upgrading MySQL
********************************

* Menu:

* installation-overview:: MySQL Installation Overview
* installation-version:: Determining your current MySQL version
* installing-es:: Notes for MySQL Enterprise Server
* installing-cs:: Notes for MySQL Community Server
* getting-mysql:: How to Get MySQL
* verifying-package-integrity:: Verifying Package Integrity Using MD5 Checksums or `GnuPG'
* installation-layouts:: Installation Layouts
* compiler-characteristics:: Compiler-Specific Build Characteristics
* quick-standard-installation:: Standard MySQL Installation from a Binary Distribution
* windows-installation:: Installing MySQL on Microsoft Windows
* macosx-installation:: Installing MySQL on Mac OS X
* linux-installation-rpm:: Installing MySQL from RPM Packages on Linux
* solaris-installation:: Installing MySQL on Solaris
* i5os-installation:: Installing MySQL on i5/OS
* netware-installation:: Installing MySQL on NetWare
* binary-installation:: Installing MySQL from Generic Binaries on Other Unix-Like Systems
* source-installation:: Installing MySQL from Source
* postinstallation:: Postinstallation Setup and Testing
* upgrading-downgrading:: Upgrading or Downgrading MySQL
* operating-system-specific-notes:: Operating System-Specific Notes
* environment-variables:: Environment Variables
* perl-support:: Perl Installation Notes

End of Product Lifecycle

File: manual.info, Node: installation-overview, Next: installation-version, Prev: installing, Up: installing

3.1 MySQL Installation Overview
===============================

This chapter describes how to obtain and install MySQL. You can choose
to install MySQL Enterprise or MySQL Community Server:

* MySQL Enterprise is Oracle Corporation's commercial offering for
modern enterprise businesses. It includes MySQL Enterprise Server
and the services provided by MySQL Network. To install MySQL
Enterprise, see *Note installing-es::.

* MySQL Community Server is for users who are comfortable
configuring and administering MySQL by themselves. To install
MySQL Community Server, see *Note installing-cs::.

If you plan to upgrade an existing version of MySQL to a newer version
rather than install MySQL for the first time, see *Note upgrading::,
for information about upgrade procedures and about issues that you
should consider before upgrading.

If you are interested in migrating to MySQL from another database
system, you may wish to read *Note faqs-migration::, which contains
answers to some common questions concerning migration issues.

File: manual.info, Node: installation-version, Next: installing-es, Prev: installation-overview, Up: installing

3.2 Determining your current MySQL version
==========================================

To determine the version and release of your currently installed MySQL
installation, there are a number of options.

* Using a command client (`mysql'), the server version of the MySQL
server to which you are connected is shown once you are connected.
The server version information includes `community' or `enterprise'
accordingly.

For example, here is the output from a MySQL Community Server
edition installed on Linux:

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.0.27-standard MySQL Community Edition - Standard (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

This is an example of the output from MySQL Enterprise Server on
Windows:

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.0.28-enterprise-gpl-nt MySQL Enterprise Server (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

* You may also determine the version information using the version
variables. Both the version and version_comment variables contain
version information for the server to which you are connected. Use
the *Note `SHOW VARIABLES': show-variables. statement to obtain
the information you want, as shown in this example:

*Note*:

You can also obtain server version information in the *Note
`mysql': mysql. client using the *Note `SELECT': select.
`VERSION()' statement. In addition, MySQL Administrator also shows
the server version in the `Server Information' tab. However, in
both of these cases, only the value of `version' is shown.

* The `STATUS' command displays the version as well as version
comment information. For example:

mysql> STATUS;
--------------
./client/mysql Ver 14.12 Distrib 5.0.29, for pc-linux-gnu (i686) using readline 5.0

Connection id: 8
Current database:
Current user: mc@localhost
SSL: Not in use
Current pager: /usr/bin/less
Using outfile: ''
Using delimiter: ;
Server version: 5.0.27-standard MySQL Community Edition - Standard (GPL)
Protocol version: 10
Connection: Localhost via UNIX socket
Server characterset: latin1
Db characterset: latin1
Client characterset: latin1
Conn. characterset: latin1
UNIX socket: /tmp/mysql.sock
Uptime: 1 day 3 hours 58 min 43 sec

Threads: 2 Questions: 17 Slow queries: 0 Opens: 11 Flush tables: 1 Open tables: 6 Queries per second avg: 0.000
--------------

File: manual.info, Node: installing-es, Next: installing-cs, Prev: installation-version, Up: installing

3.3 Notes for MySQL Enterprise Server
=====================================

* Menu:

* installing-es-disttypes:: Enterprise Server Distribution Types
* installing-es-upgrade:: Upgrading MySQL Enterprise Server

To obtain MySQL Enterprise, visit `http://enterprise.mysql.com' if
you're a customer. Otherwise, visit
http://www.mysql.com/products/enterprise/. The platforms that are
officially supported for MySQL Enterprise are listed at
http://www.mysql.com/support/supportedplatforms.html.

MySQL Enterprise Server is available for download in the form of
_Quarterly Service Pack (QSP)_ or _Monthly Rapid Update (MRU)_ binary
releases.

To install MySQL Enterprise Server, you should use the latest available
Quarterly Service Pack (QSP). This includes an accumulation of the bug
fixes provided in all predecessor QSP and MRU releases.

MRU releases are provided on a monthly basis and represent the most
current Enterprise Server bug fixes. Each MRU is an accumulation of the
bug fixes included in its predecessor. Customers should standardize on
the latest MRU release only if it includes a needed bug fix.

File: manual.info, Node: installing-es-disttypes, Next: installing-es-upgrade, Prev: installing-es, Up: installing-es

3.3.1 Enterprise Server Distribution Types
------------------------------------------

Enterprise Server releases will be created for the following packages
from the MySQL 5.0 tree:

* `mysql-enterprise': Released under a commercial license and
includes the following storage engines: `MyISAM', `MEMORY',
`MERGE', `InnoDB', `ARCHIVE', `BLACKHOLE', `EXAMPLE', `FEDERATED'.

* `mysql-enterprise-gpl': Same as `mysql-enterprise', but released
under the GPL.

* `mysql-cluster': `mysql-enterprise' plus MySQL Cluster (*Note
`NDB': mysql-cluster.).

* `mysql-classic': Released under a commercial license, does not
include `InnoDB'.

* `mysql-community': Same as `mysql-enterprise-gpl', but available
for the community, and released every 6 months.

To satisfy different user requirements, we provide several servers.
*Note `mysqld': mysqld. is an optimized server that is a smaller,
faster binary. *Note `mysqld-debug': mysqld. is compiled with debugging
support but is otherwise configured identically to the nondebug server.

Each of these servers is compiled from the same source distribution,
though with different configuration options. All native MySQL clients
can connect to servers from either MySQL version.

File: manual.info, Node: installing-es-upgrade, Prev: installing-es-disttypes, Up: installing-es

3.3.2 Upgrading MySQL Enterprise Server
---------------------------------------

When upgrading to MySQL Enterprise from Community Server you need only
follow the installation process to install and upgrade the packages to
the latest version provided by MySQL Enterprise. You will also need to
install the latest MySQL Enterprise Service Pack and any outstanding
MySQL Hot-fix packs.

Be aware, however, that you must take into account any of the changes
when moving between major releases. You should also check the release
notes for details on major changes between revisions of MySQL
Enterprise Server (see *Note news::).

You should also review the notes and advice contained within *Note
upgrading::.

File: manual.info, Node: installing-cs, Next: getting-mysql, Prev: installing-es, Up: installing

3.4 Notes for MySQL Community Server
====================================

* Menu:

* installing-cs-overview:: Overview of MySQL Community Server Installation
* supported-os:: Operating Systems Supported by MySQL Community Server
* which-version:: Choosing Which MySQL Distribution to Install

File: manual.info, Node: installing-cs-overview, Next: supported-os, Prev: installing-cs, Up: installing-cs

3.4.1 Overview of MySQL Community Server Installation
-----------------------------------------------------

1. Determine whether MySQL runs and is supported on your platform

Not all platforms are equally suitable for running MySQL, and not
all platforms on which MySQL is known to run are officially
supported by Oracle Corporation. For a list of platforms on which
MySQL Community Server runs, see *Note supported-os::.

2. Choose which distribution to install

Several versions of MySQL are available, and most are available in
multiple distribution formats. You can choose from prepackaged
distributions containing binary (precompiled) programs or source
code. When in doubt, use a binary distribution. We also provide
public access to our current source trees for those who want to
see our most recent developments and to help us test new code. To
determine which version and type of distribution you should use,
see *Note which-version::.

3. Download the distribution that you want to install

For download instructions, see *Note getting-mysql::. To verify
the integrity of the distribution, use the instructions in *Note
verifying-package-integrity::.

4. Install the distribution

To install MySQL from a binary distribution, use the instructions
in *Note quick-standard-installation::. To install MySQL from a
source distribution or from the current development source tree,
use the instructions in *Note source-installation::.

If you encounter installation difficulties, see *Note
operating-system-specific-notes::, for information on solving
problems for particular platforms.

5. Perform any necessary postinstallation setup

After installing MySQL, read *Note postinstallation::, which
contains important information about making sure the MySQL server
is working properly. It also describes how to secure the initial
MySQL user accounts, _which have no passwords_ until you assign
passwords. The information in this section applies whether you
install MySQL using a binary or source distribution.

6. Perform setup for running benchmarks (optional)

If you want to use the MySQL benchmark scripts, Perl support for
MySQL must be available. See *Note perl-support::, for more
information.

The sections immediately following this one contain necessary
information about choosing, downloading, and verifying your
distribution. The instructions in later sections of the chapter
describe how to install the distribution that you choose. For binary
distributions, see the instructions in *Note
quick-standard-installation::. To build MySQL from source, use the
instructions in *Note source-installation::.

File: manual.info, Node: supported-os, Next: which-version, Prev: installing-cs-overview, Up: installing-cs

3.4.2 Operating Systems Supported by MySQL Community Server
-----------------------------------------------------------

This section lists the operating systems on which MySQL Community
Server is known to run.

*Important*:

Oracle Corporation does not necessarily provide official support for
all the platforms listed in this section. For information about those
platforms that are officially supported, see
http://www.mysql.com/support/supportedplatforms.html on the MySQL Web
site.

We use GNU Autoconf, so it is possible to port MySQL to all modern
systems that have a C++ compiler and a working implementation of POSIX
threads. (Thread support is needed for the server. To compile only the
client code, the only requirement is a C++ compiler.)

MySQL has been reported to compile successfully on the following
combinations of operating system and thread package.

* AIX 4.x and 5.x with native threads. See *Note ibm-aix::. AIX 5.3
should be upgraded to technology level 7 (5300-07).

* Amiga.

* FreeBSD 5.x and up with native threads.

* HP-UX 11.x with native threads. See *Note hp-ux-11-x::.

* Linux. MySQL builds on all fairly recent Linux distributions with
`glibc' 2.3. See *Note linux::.

* Mac OS X. See *Note macosx-installation::.

* NetBSD 1.3/1.4 Intel and NetBSD 1.3 Alpha. See *Note netbsd::.

* Novell NetWare 6.0 and 6.5. See *Note netware-installation::.

* SCO OpenServer 5.0.X with a recent port of the FSU Pthreads
package. See *Note sco::.

* SCO Openserver 6.0.x. See *Note sco-openserver::.

* SCO UnixWare 7.1.x. See *Note sco-unixware::.

* SGI Irix 6.x with native threads. See *Note sgi-irix::.

* Solaris 2.5 and above with native threads on SPARC and x86. See
*Note solaris::.

* Tru64 Unix. See *Note alpha-dec-unix::.

* Windows 2000, XP, Windows Server 2003, Windows Vista, and Windows
Server 2008. See *Note windows-installation::.

MySQL has also been known to run on other systems in the past. See
*Note operating-system-specific-notes::. Some porting effort might be
required for current versions of MySQL on these systems.

Not all platforms are equally well suited for running MySQL. How well a
certain platform is suited for a high-load mission-critical MySQL
server is determined by the following factors:

* General stability of the thread library

A platform may have an excellent reputation otherwise, but MySQL
is only as stable as the thread library it calls, even if
everything else is perfect.

* The capability of the kernel and the thread library to take
advantage of symmetric multi-processor (SMP) systems

When a process creates a thread, it should be possible for that
thread to run on a CPU different from the original process.

* Multi-threading and handling of mutexes

The capability of the kernel and the thread library to run many
threads that acquire and release a mutex over a short critical
region frequently without excessive context switches. If the
implementation of `pthread_mutex_lock()' does not easily yield CPU
time, this hurts MySQL tremendously. If this issue is not taken
care of, adding extra CPUs actually makes MySQL slower.

* File system stability and performance

MySQL's stability and performance are directly affected by those
of the operating platform's file system. In particular, where
large tables are in use, performance is affected by the ability of
the file system to deal with large files at all and to deal with
them efficiently.

* Expertise with the platform

If we know a platform well, we enable platform-specific
optimizations and fixes at compile time. We can also provide
advice on configuring your system optimally for MySQL. This is
also affected by the amount of testing we have done internally for
similar configurations, as well as by the number of users that
have run MySQL successfully on the platform in similar
configurations. If these figures are high, the likelihood of
encountering platform-specific surprises is much smaller.

File: manual.info, Node: which-version, Prev: supported-os, Up: installing-cs

3.4.3 Choosing Which MySQL Distribution to Install
--------------------------------------------------

* Menu:

* choosing-version:: Choosing Which Version of MySQL to Install
* choosing-distribution-format:: Choosing a Distribution Format
* many-versions:: How and When Updates Are Released
* mysql-binaries:: MySQL Binaries Compiled by Oracle Corporation

When preparing to install MySQL, you should decide which version to
use. MySQL development occurs in several release series, and you can
pick the one that best fits your needs. After deciding which version to
install, you can choose a distribution format. Releases are available
in binary or source format.

File: manual.info, Node: choosing-version, Next: choosing-distribution-format, Prev: which-version, Up: which-version

3.4.3.1 Choosing Which Version of MySQL to Install
..................................................

The first decision to make is whether you want to use a production
(stable) release or a development release. In the MySQL development
process, multiple release series co-exist, each at a different stage of
maturity.

Production Releases

* MySQL 5.5: Latest General Availability (Production) release

* MySQL 5.1: Previous stable (production-quality) release

* MySQL 5.0: Older stable release nearing the end of the product
lifecycle

Development Release

* MySQL 5.6: Current release under development (pre-Production)

MySQL 4.1, 4.0, and 3.23 are old releases that are no longer supported.

See http://www.mysql.com/about/legal/lifecycle/ for information about
support policies and schedules.

Normally, if you are beginning to use MySQL for the first time or
trying to port it to some system for which there is no binary
distribution, use the most recent General Availability series listed in
the preceding descriptions. All MySQL releases, even those from
development series, are checked with the MySQL benchmarks and an
extensive test suite before being issued.

If you are running an older system and want to upgrade, but do not want
to take the chance of having a nonseamless upgrade, you should upgrade
to the latest version in the same release series you are using (where
only the last part of the version number is newer than yours). We have
tried to fix only fatal bugs and make only small, relatively `safe'
changes to that version.

If you want to use new features not present in the production release
series, you can use a version from a development series. Be aware that
development releases are not as stable as production releases.

We do not use a complete code freeze because this prevents us from
making bugfixes and other fixes that must be done. We may add small
things that should not affect anything that currently works in a
production release. Naturally, relevant bugfixes from an earlier series
propagate to later series.

If you want to use the very latest sources containing all current
patches and bugfixes, you can use one of our source code repositories
(see *Note installing-development-tree::). These are not `releases' as
such, but are available as previews of the code on which future
releases are to be based.

The naming scheme in MySQL 5.0 uses release names that consist of three
numbers and a suffix; for example, *mysql-5.0.14-rc*. The numbers
within the release name are interpreted as follows:

* The first number (*5*) is the major version and describes the file
format. All MySQL 5 releases have the same file format.

* The second number (*0*) is the release level. Taken together, the
major version and release level constitute the release series
number.

* The third number (*14*) is the version number within the release
series. This is incremented for each new release. Usually you want
the latest version for the series you have chosen.

For each minor update, the last number in the version string is
incremented. When there are major new features or minor
incompatibilities with previous versions, the second number in the
version string is incremented. When the file format changes, the first
number is increased.

Release names also include a suffix to indicates the stability level of
the release. Releases within a series progress through a set of
suffixes to indicate how the stability level improves. The possible
suffixes are:

* *alpha* indicates that the release is for preview purposes only.
Known bugs should be documented in the News section (see *Note
news::). Most alpha releases implement new commands and
extensions. Active development that may involve major code
changes can occur in an alpha release. However, we do conduct
testing before issuing a release.

* *beta* indicates that the release is appropriate for use with new
development. Within beta releases, the features and compatibility
should remain consistent. However, beta releases may contain
numerous and major unaddressed bugs.

No APIs, externally visible structures, or columns for SQL
statements will change during future beta, release candidate, or
production releases.

* *rc* indicates a Release Candidate. Release candidates are
believed to be stable, having passed all of MySQL's internal
testing, and with all known fatal runtime bugs fixed. However, the
release has not been in widespread use long enough to know for
sure that all bugs have been identified. Only minor fixes are
added. (A release candidate is what formerly was known as a gamma
release.)

* If there is no suffix, it indicates that the release is a General
Availability (GA) or Production release. GA releases are stable,
having successfully passed through all earlier release stages and
are believed to be reliable, free of serious bugs, and suitable
for use in production systems. Only critical bugfixes are applied
to the release.

All releases of MySQL are run through our standard tests and benchmarks
to ensure that they are relatively safe to use. Because the standard
tests are extended over time to check for all previously found bugs,
the test suite keeps getting better.

All releases have been tested at least with these tools:

* An internal test suite

The `mysql-test' directory contains an extensive set of test
cases. We run these tests for every server binary. See *Note
mysql-test-suite::, for more information about this test suite.

* The MySQL benchmark suite

This suite runs a range of common queries. It is also a test to
determine whether the latest batch of optimizations actually made
the code faster. See *Note mysql-benchmarks::.

We also perform additional integration and nonfunctional testing of the
latest MySQL version in our internal production environment.
Integration testing is done with different connectors, storage engines,
replication modes, backup, partitioning, stored programs, and so forth
in various combinations. Additional nonfunctional testing is done in
areas of performance, concurrency, stress, high volume, upgrade and
downgrade.

File: manual.info, Node: choosing-distribution-format, Next: many-versions, Prev: choosing-version, Up: which-version

3.4.3.2 Choosing a Distribution Format
......................................

After choosing which version of MySQL to install, you should decide
whether to use a binary distribution or a source distribution. In most
cases, you should probably use a binary distribution, if one exists for
your platform. Binary distributions are available in native format for
many platforms, such as RPM files for Linux or PKG package installers
for Mac OS X or Solaris. Distributions also are available as Zip
archives or compressed `tar' files.

Reasons to choose a binary distribution include the following:

* Binary distributions generally are easier to install than source
distributions.

* To satisfy different user requirements, we provide several servers
in binary distributions. *Note `mysqld': mysqld. is an optimized
server that is a smaller, faster binary. *Note `mysqld-debug':
mysqld. is compiled with debugging support.

Each of these servers is compiled from the same source
distribution, though with different configuration options. All
native MySQL clients can connect to servers from either MySQL
version.

Under some circumstances, you may be better off installing MySQL from a
source distribution:

* You want to install MySQL at some explicit location. The standard
binary distributions are ready to run at any installation
location, but you might require even more flexibility to place
MySQL components where you want.

* You want to configure *Note `mysqld': mysqld. to ensure that
features are available that might not be included in the standard
binary distributions. Here is a list of the most common extra
options that you may want to use to ensure feature availability:

* `--with-berkeley-db' (not available on all platforms)

* `--with-libwrap'

* `--with-named-z-libs' (this is done for some of the binaries)

* `--with-debug[=full]'

* You want to configure *Note `mysqld': mysqld. without some
features that are included in the standard binary distributions.
For example, distributions normally are compiled with support for
all character sets. If you want a smaller MySQL server, you can
recompile it with support for only the character sets you need.

* You want to use the latest sources from one of the Bazaar
repositories to have access to all current bugfixes. For example,
if you have found a bug and reported it to the MySQL development
team, the bugfix is committed to the source repository and you can
access it there. The bugfix does not appear in a release until a
release actually is issued.

* You want to read (or modify) the C and C++ code that makes up
MySQL. For this purpose, you should get a source distribution,
because the source code is always the ultimate manual.

* Source distributions contain more tests and examples than binary
distributions.

File: manual.info, Node: many-versions, Next: mysql-binaries, Prev: choosing-distribution-format, Up: which-version

3.4.3.3 How and When Updates Are Released
.........................................

MySQL is evolving quite rapidly and we want to share new developments
with other MySQL users. We try to produce a new release whenever we
have new and useful features that others also seem to have a need for.

We also try to help users who request features that are easy to
implement. We take note of what our licensed users want, and we
especially take note of what our support customers want and try to help
them in this regard.

No one is _required_ to download a new release. The `News' section
helps you determine whether the new release has something you really
want. See *Note news::.

We use the following policy when updating MySQL:

* Enterprise Server releases are meant to appear every 18 months,
supplemented by quarterly service packs and monthly rapid updates.
Community Server releases are meant to appear 2-3 times per year.

* Releases are issued within each series. For each release, the last
number in the version is one more than the previous release within
the same series.

* Binary distributions for some platforms are made by us for major
releases. Other people may make binary distributions for other
systems, but probably less frequently.

* We make fixes available as soon as we have identified and
corrected small or noncritical but annoying bugs. The fixes are
available in source form immediately from our public Bazaar
repositories, and are included in the next release.

* If by any chance a security vulnerability or critical bug is found
in a release, our policy is to fix it in a new release as soon as
possible. (We would like other companies to do this, too!)

File: manual.info, Node: mysql-binaries, Prev: many-versions, Up: which-version

3.4.3.4 MySQL Binaries Compiled by Oracle Corporation
.....................................................

Oracle Corporation provides a set of binary distributions of MySQL. In
addition to binaries provided in platform-specific package formats, we
offer binary distributions for a number of platforms in the form of
compressed `tar' files (`.tar.gz' files). See *Note
quick-standard-installation::. For Windows distributions, see *Note
windows-installation::.

If you want to compile MySQL from a source distribution, see *Note
source-installation::. To compile a debug version of MySQL, see *Note
source-configuration-options:: for options that enable debugging.

File: manual.info, Node: getting-mysql, Next: verifying-package-integrity, Prev: installing-cs, Up: installing

3.5 How to Get MySQL
====================

Check our downloads page at `http://dev.mysql.com/downloads/' for
information about the current version of MySQL and for downloading
instructions. For a complete up-to-date list of MySQL download mirror
sites, see `http://dev.mysql.com/downloads/mirrors.html'. You can also
find information there about becoming a MySQL mirror site and how to
report a bad or out-of-date mirror.

To obtain the latest development source, see *Note
installing-development-tree::.

File: manual.info, Node: verifying-package-integrity, Next: installation-layouts, Prev: getting-mysql, Up: installing

3.6 Verifying Package Integrity Using MD5 Checksums or `GnuPG'
==============================================================

* Menu:

* verifying-md5-checksum:: Verifying the MD5 Checksum
* checking-gpg-signature:: Signature Checking Using `GnuPG'
* checking-rpm-signature:: Signature Checking Using `RPM'

After you have downloaded the MySQL package that suits your needs and
before you attempt to install it, you should make sure that it is
intact and has not been tampered with. There are three means of
integrity checking:

* MD5 checksums

* Cryptographic signatures using `GnuPG', the GNU Privacy Guard

* For RPM packages, the built-in RPM integrity verification mechanism

The following sections describe how to use these methods.

If you notice that the MD5 checksum or GPG signatures do not match,
first try to download the respective package one more time, perhaps
from another mirror site. If you repeatedly cannot successfully verify
the integrity of the package, please notify us about such incidents,
including the full package name and the download site you have been
using, at <webmaster@mysql.com> or <build@mysql.com>. Do not report
downloading problems using the bug-reporting system.

File: manual.info, Node: verifying-md5-checksum, Next: checking-gpg-signature, Prev: verifying-package-integrity, Up: verifying-package-integrity

3.6.1 Verifying the MD5 Checksum
--------------------------------

After you have downloaded a MySQL package, you should make sure that
its MD5 checksum matches the one provided on the MySQL download pages.
Each package has an individual checksum that you can verify with the
following command, where PACKAGE_NAME is the name of the package you
downloaded:

shell> md5sum PACKAGE_NAME

Example:

shell> md5sum mysql-standard-5.0.93-linux-i686.tar.gz
aaab65abbec64d5e907dcd41b8699945 mysql-standard-5.0.93-linux-i686.tar.gz

You should verify that the resulting checksum (the string of
hexadecimal digits) matches the one displayed on the download page
immediately below the respective package.

*Note*:

Make sure to verify the checksum of the _archive file_ (for example,
the `.zip' or `.tar.gz' file) and not of the files that are contained
inside of the archive.

Note that not all operating systems support the `md5sum' command. On
some, it is simply called `md5', and others do not ship it at all. On
Linux, it is part of the *GNU Text Utilities* package, which is
available for a wide range of platforms. You can download the source
code from `http://www.gnu.org/software/textutils/' as well. If you
have OpenSSL installed, you can use the command `openssl md5
PACKAGE_NAME' instead. A Windows implementation of the `md5' command
line utility is available from `http://www.fourmilab.ch/md5/'.
`winMd5Sum' is a graphical MD5 checking tool that can be obtained from
`http://www.nullriver.com/index/products/winmd5sum'.

File: manual.info, Node: checking-gpg-signature, Next: checking-rpm-signature, Prev: verifying-md5-checksum, Up: verifying-package-integrity

3.6.2 Signature Checking Using `GnuPG'
--------------------------------------

Another method of verifying the integrity and authenticity of a package
is to use cryptographic signatures. This is more reliable than using
MD5 checksums, but requires more work.

We sign MySQL downloadable packages with `GnuPG' (GNU Privacy Guard).
`GnuPG' is an Open Source alternative to the well-known Pretty Good
Privacy (`PGP') by Phil Zimmermann. See `http://www.gnupg.org/' for more
information about `GnuPG' and how to obtain and install it on your
system. Most Linux distributions ship with `GnuPG' installed by
default. For more information about `GnuPG', see
`http://www.openpgp.org/'.

To verify the signature for a specific package, you first need to
obtain a copy of our public GPG build key, which you can download from
`http://keyserver.pgp.com/'. The key that you want to obtain is named
`build@mysql.com'. Alternatively, you can cut and paste the key
directly from the following text:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.5 (GNU/Linux)
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=Mski

-----END PGP PUBLIC KEY BLOCK-----

To import the build key into your personal public GPG keyring, use `gpg
--import'. For example, if you have saved the key in a file named
`mysql_pubkey.asc', the import command looks like this:

shell> gpg --import mysql_pubkey.asc
gpg: key 5072E1F5: public key "MySQL Package signing key (www.mysql.com) <build@mysql.com>" imported
gpg: Total number processed: 1
gpg: imported: 1
gpg: no ultimately trusted keys found

You can also download the key from the public keyserver using the
public key id, `5072E1F5':

shell> gpg --recv-keys 5072E1F5
gpg: requesting key 5072E1F5 from hkp server subkeys.pgp.net
gpg: key 5072E1F5: "MySQL Package signing key (www.mysql.com) <build@mysql.com>" 2 new signatures
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg: new signatures: 2

If you want to import the key into your RPM configuration to validate
RPM install packages, you should be able to import the key directly:

shell> rpm --import mysql_pubkey.asc

If you experience problems, try exporting the key from `gpg' and
importing:

shell> gpg --export -a 5072e1f5 > 5072e1f5.asc
shell> rpm --import 5072e1f5.asc

Alternatively, `rpm' also supports loading the key directly from a URL,
and you cas use this manual page:

shell> rpm --import http://dev.mysql.com/doc/refman/5.0/en/checking-gpg-signature.html

After you have downloaded and imported the public build key, download
your desired MySQL package and the corresponding signature, which also
is available from the download page. The signature file has the same
name as the distribution file with an `.asc' extension, as shown by the
examples in the following table.

File Type File Name
Distribution file `mysql-standard-5.0.93-linux-i686.tar.gz'
Signature file `mysql-standard-5.0.93-linux-i686.tar.gz.asc'

Make sure that both files are stored in the same directory and then run
the following command to verify the signature for the distribution file:

shell> gpg --verify PACKAGE_NAME.asc

Example:

shell> gpg --verify mysql-standard-5.0.93-linux-i686.tar.gz.asc
gpg: Signature made Tue 12 Jul 2005 23:35:41 EST using DSA key ID 5072E1F5
gpg: Good signature from "MySQL Package signing key (www.mysql.com) <build@mysql.com>"

The `Good signature' message indicates that everything is all right.
You can ignore any `insecure memory' warning you might obtain.

See the GPG documentation for more information on how to work with
public keys.

File: manual.info, Node: checking-rpm-signature, Prev: checking-gpg-signature, Up: verifying-package-integrity

3.6.3 Signature Checking Using `RPM'
------------------------------------

For RPM packages, there is no separate signature. RPM packages have a
built-in GPG signature and MD5 checksum. You can verify a package by
running the following command:

shell> rpm --checksig PACKAGE_NAME.rpm

Example:

shell> rpm --checksig MySQL-server-5.0.93-0.glibc23.i386.rpm
MySQL-server-5.0.93-0.glibc23.i386.rpm: md5 gpg OK

*Note*:

If you are using RPM 4.1 and it shows the error `(GPG) NOT OK (MISSING
KEYS: GPG#5072e1f5)' even though you have imported the MySQL public
build key into your own GPG keyring, you need to import the key into
the RPM keyring first. RPM 4.1 no longer uses your personal GPG keyring
(or GPG itself). Rather, it maintains its own keyring because it is a
system-wide application and a user's GPG public keyring is a
user-specific file. To import the MySQL public key into the RPM keyring,
first obtain the key as described in *Note checking-gpg-signature::.
Then use `rpm --import' to import the key. For example, if you have
saved the public key in a file named `mysql_pubkey.asc', import it
using this command:

shell> rpm --import mysql_pubkey.asc

If you need to obtain the MySQL public key, see *Note
checking-gpg-signature::.

File: manual.info, Node: installation-layouts, Next: compiler-characteristics, Prev: verifying-package-integrity, Up: installing

3.7 Installation Layouts
========================

This section describes the default layout of the directories created by
installing binary or source distributions provided by Oracle
Corporation. A distribution provided by another vendor might use a
layout different from those shown here.

For MySQL 5.0 on Windows, the default installation directory is
`C:\Program Files\MySQL\MySQL Server 5.0'. (Some Windows users prefer
to install in `C:\mysql', the directory that formerly was used as the
default. However, the layout of the subdirectories remains the same.)
The installation directory has the following subdirectories:

*MySQL Installation Layout for Windows*

Directory Contents of Directory
`bin' Client programs and the *Note `mysqld':
mysqld. server
`data' Log files, databases
`examples' Example programs and scripts
`include' Include (header) files
`lib' Libraries
`scripts' Utility scripts
`share' Miscellaneous support files, including error
messages, character set files, sample
configuration files, SQL for database
installation

Installations created from our Linux RPM distributions result in files
under the following system directories:

*MySQL Installation Layout for Linux RPM*

Directory Contents of Directory
`/usr/bin' Client programs and scripts
`/usr/sbin' The *Note `mysqld': mysqld. server
`/var/lib/mysql' Log files, databases
`/usr/share/info' Manual in Info format
`/usr/share/man' Unix man pages
`/usr/include/mysql' Include (header) files
`/usr/lib/mysql' Libraries
`/usr/share/mysql' Miscellaneous support files, including error
messages, character set files, sample
configuration files, SQL for database
installation
`/usr/share/sql-bench' Benchmarks

On Unix, a `tar' file binary distribution is installed by unpacking it
at the installation location you choose (typically `/usr/local/mysql')
and creates the following directories in that location:

*MySQL Installation Layout for Generic Unix/Linux Binary Package*

Directory Contents of Directory
`bin' Client programs and the *Note `mysqld':
mysqld. server
`data' Log files, databases
`docs' Manual in Info format
`man' Unix manual pages
`include' Include (header) files
`lib' Libraries
`scripts' *Note `mysql_install_db': mysql-install-db.
`share/mysql' Miscellaneous support files, including error
messages, character set files, sample
configuration files, SQL for database
installation
`sql-bench' Benchmarks

By default, when you install MySQL after compiling it from a source
distribution, the installation step installs files under `/usr/local'.
Components are installed in the directories shown in the following
table. To configure particular installation locations, use the options
described at *Note source-configuration-options::.

*MySQL Layout for Installation from Source*

Directory Contents of Directory
`bin' Client programs and scripts
`include/mysql' Include (header) files
`Docs' Manual in Info format
`man' Unix manual pages
`lib/mysql' Libraries
`libexec' The *Note `mysqld': mysqld. server
`share/mysql' Miscellaneous support files, including error
messages, character set files, sample
configuration files, SQL for database
installation
`sql-bench' Benchmarks
`var' Log files, databases

Within its installation directory, the layout of a source installation
differs from that of a binary installation in the following ways:

* The *Note `mysqld': mysqld. server is installed in the `libexec'
directory rather than in the `bin' directory.

* The data directory is `var' rather than `data'.

* *Note `mysql_install_db': mysql-install-db. is installed in the
`bin' directory rather than in the `scripts' directory.

* The header file and library directories are `include/mysql' and
`lib/mysql' rather than `include' and `lib'.

To create your own binary installation from a compiled source
distribution, execute the `scripts/make_binary_distribution' script from
the top directory of the source distribution.

File: manual.info, Node: compiler-characteristics, Next: quick-standard-installation, Prev: installation-layouts, Up: installing

3.8 Compiler-Specific Build Characteristics
===========================================

In some cases, the compiler used to build MySQL affects the features
available for use. The notes in this section apply for binary
distributions provided by Oracle Corporation or that you compile
yourself from source.

*`icc' (Intel C++ Compiler) Builds*

A server built with `icc' has these characteristics:

* SSL support is not included.

File: manual.info, Node: quick-standard-installation, Next: windows-installation, Prev: compiler-characteristics, Up: installing

3.9 Standard MySQL Installation from a Binary Distribution
==========================================================

The next several sections cover the installation of MySQL on platforms
where we offer packages using the native packaging format of the
respective platform. (This is also known as performing a binary
installation.) However, binary distributions of MySQL are available for
many other platforms as well. See *Note binary-installation::, for
generic installation instructions for these packages that apply to all
platforms.

See *Note installing-cs::, for more information on what other binary
distributions are available and how to obtain them.

File: manual.info, Node: windows-installation, Next: macosx-installation, Prev: quick-standard-installation, Up: installing

3.10 Installing MySQL on Microsoft Windows
==========================================

* Menu:

* windows-choosing-package:: Choosing An Installation Package
* windows-using-installer:: Installing MySQL with the Automated Installer
* mysql-config-wizard:: MySQL Server Instance Configuration Wizard
* windows-install-archive:: Installing MySQL from a Noinstall Zip Archive
* windows-troubleshooting:: Troubleshooting a MySQL Installation Under Windows
* windows-upgrading:: Upgrading MySQL on Windows
* windows-postinstallation:: Windows Postinstallation Procedures
* windows-source-build:: Installing MySQL from Source on Windows

A native Windows distribution of MySQL has been available since version
3.21 and represents a sizable percentage of the daily downloads of
MySQL. This section describes the process for installing MySQL on
Windows.

*Note*:

If you are upgrading MySQL from an existing installation older than
MySQL 4.1.5, you must first perform the procedure described in *Note
windows-upgrading::.

To run MySQL on Windows, you need the following:

* A Windows operating system such as 2000, XP, Vista, Server 2008,
or newer. Only 32-bit and 64-bit versions of Windows 2000 and
later are supported. Windows 95/98/ME and versions of Windows
older than these are no longer supported.

A Windows operating system permits you to run the MySQL server as
a service. See *Note windows-start-service::.

Generally, you should install MySQL on Windows using an account
that has administrator rights. Otherwise, you may encounter
problems with certain operations such as editing the `PATH'
environment variable or accessing the `Service Control Manager'.

* TCP/IP protocol support.

* Enough space on the hard drive to unpack, install, and create the
databases in accordance with your requirements (generally a
minimum of 200 megabytes is recommended.)

For a list of limitations within the Windows version of MySQL, see
*Note limits-windows::.

There may also be other requirements, depending on how you plan to use
MySQL:

* If you plan to connect to the MySQL server using ODBC, you need a
Connector/ODBC driver. See *Note connectors-apis::.

* If you need tables with a size larger than 4GB, install MySQL on
an NTFS or newer file system. Do not forget to use `MAX_ROWS' and
`AVG_ROW_LENGTH' when you create tables. See *Note create-table::.

MySQL for Windows is available in several distribution formats:

* Binary distributions are available that contain a setup program
that installs everything you need so that you can start the server
immediately. Another binary distribution format contains an
archive that you simply unpack in the installation location and
then configure yourself. For details, see *Note
windows-choosing-package::.

* The source distribution contains all the code and support files
for building the executables using the Visual Studio compiler
system.

Generally speaking, you should use a binary distribution that includes
an installer. It is simpler to use than the others, and you need no
additional tools to get MySQL up and running. The installer for the
Windows version of MySQL, combined with a GUI Configuration Wizard,
automatically installs MySQL, creates an option file, starts the
server, and secures the default user accounts.

*Caution*:

Using virus scanning software such as Norton/Symantec Anti-Virus on
directories containing MySQL data and temporary tables can cause
issues, both in terms of the performance of MySQL and the
virus-scanning software mis-identifying the contents of the files as
containing spam. This is because of the fingerprinting mechanism used
by the virus scanning software, and the way in which MySQL rapidly
updates different files, which may be identified as a potential
security risk.

After installing MySQL Server, it is recommended that you disable virus
scanning on the main directory (`datadir') being used to store your
MySQL table data. There is usually a system built into the virus
scanning software to permit certain directories to be specifically
ignored during virus scanning.

In addition, by default, MySQL creates temporary files in the standard
Windows temporary directory. To prevent the temporary files also being
scanned, you should configure a separate temporary directory for MySQL
temporary files and add this to the virus scanning exclusion list. To
do this, add a configuration option for the `tmpdir' parameter to your
`my.ini' configuration file. For more information, see *Note
windows-create-option-file::.

The following section describes how to install MySQL on Windows using a
binary distribution. To use an installation package that does not
include an installer, follow the procedure described in *Note
windows-install-archive::. To install using a source distribution, see
*Note windows-source-build::.

MySQL distributions for Windows can be downloaded from
`http://dev.mysql.com/downloads/'. See *Note getting-mysql::.

File: manual.info, Node: windows-choosing-package, Next: windows-using-installer, Prev: windows-installation, Up: windows-installation

3.10.1 Choosing An Installation Package
---------------------------------------

For MySQL 5.0, there are three installation packages to choose from
when installing MySQL on Windows:

* The Essentials package

This package has a file name similar to
`mysql-essential-5.0.93-win32.msi' and contains the minimum set of
files needed to install MySQL on Windows, including the
Configuration Wizard. This package does not include optional
components such as the embedded server and benchmark suite.

* The Complete package

This package has a file name similar to `mysql-5.0.93-win32.zip'
and contains all files needed for a complete Windows installation,
including the Configuration Wizard. This package includes optional
components such as the embedded server and benchmark suite.

* The no-install archive

This package has a file name similar to
`mysql-noinstall-5.0.93-win32.zip' and contains all the files
found in the Complete install package, with the exception of the
Configuration Wizard. This package does not include an automated
installer, and must be manually installed and configured.

The Essentials package is recommended for most users. It is provided as
an `.msi' file for use with the Windows Installer. The Complete and
Noinstall distributions are packaged as Zip archives. To use them, you
must have a tool that can unpack `.zip' files.

Your choice of install package affects the installation process you
must follow. If you choose to install either the Essentials or Complete
install packages, see *Note windows-using-installer::. If you choose to
install MySQL from the Noinstall archive, see *Note
windows-install-archive::.

File: manual.info, Node: windows-using-installer, Next: mysql-config-wizard, Prev: windows-choosing-package, Up: windows-installation

3.10.2 Installing MySQL with the Automated Installer
----------------------------------------------------

* Menu:

* windows-install-wizard:: Using the MySQL Installation Wizard

New MySQL users can use the MySQL Installation Wizard and MySQL
Configuration Wizard to install MySQL on Windows. These are designed to
install and configure MySQL in such a way that new users can
immediately get started using MySQL.

The MySQL Installation Wizard and MySQL Configuration Wizard are
available in the Essentials and Complete install packages. They are
recommended for most standard MySQL installations. Exceptions include
users who need to install multiple instances of MySQL on a single
server host and advanced users who want complete control of server
configuration.

File: manual.info, Node: windows-install-wizard, Prev: windows-using-installer, Up: windows-using-installer

3.10.2.1 Using the MySQL Installation Wizard
............................................

* Menu:

* mysql-install-wizard-starting:: Downloading and Starting the MySQL Installation Wizard
* mysql-install-wizard-install-type:: Choosing an Installation Type
* mysql-install-wizard-custom-install:: The Custom Installation Dialog
* mysql-install-wizard-confirmation-dialog:: The Confirmation Dialog
* mysql-install-wizard-changes:: Changes Made by MySQL Installation Wizard
* mysql-install-wizard-upgrading:: Upgrading MySQL with the Installation Wizard

MySQL Installation Wizard is an installer for the MySQL server that
uses the latest installer technologies for Microsoft Windows. The MySQL
Installation Wizard, in combination with the MySQL Configuration
Wizard, enables a user to install and configure a MySQL server that is
ready for use immediately after installation.

The MySQL Installation Wizard is the standard installer for all MySQL
server distributions, version 4.1.5 and higher. Users of previous
versions of MySQL need to shut down and remove their existing MySQL
installations manually before installing MySQL with the MySQL
Installation Wizard. See *Note mysql-install-wizard-upgrading::, for
more information on upgrading from a previous version.

The Microsoft Windows Installer (MSI) is the standard for application
installations on Windows 2000 and later versions. The MySQL
Installation Wizard makes use of this technology to provide a smoother
and more flexible installation process.

The Microsoft Windows Installer Engine was updated with the release of
Windows XP; those using a previous version of Windows can reference
this Microsoft Knowledge Base article
(http://support.microsoft.com/default.aspx?scid=kb;EN-US;292539) for
information on upgrading to the latest version of the Windows Installer
Engine.

In addition, Microsoft has introduced the WiX (Windows Installer XML)
toolkit, which is the first highly acknowledged Open Source project
from Microsoft. We have switched to WiX because it is an Open Source
project and it enables us to handle the complete Windows installation
process in a flexible manner using scripts.

Improving the MySQL Installation Wizard depends on the support and
feedback of users. If you find that the MySQL Installation Wizard is
lacking some feature important to you, or if you discover a bug, please
report it in our bugs database using the instructions given in *Note
bug-reports::.

File: manual.info, Node: mysql-install-wizard-starting, Next: mysql-install-wizard-install-type, Prev: windows-install-wizard, Up: windows-install-wizard

3.10.2.2 Downloading and Starting the MySQL Installation Wizard
...............................................................

MySQL installation packages can be downloaded from
`http://dev.mysql.com/downloads/'. If the package you download is
contained within a Zip archive, you need to extract the archive first.

*Note*:

If you are installing on Windows Vista or newer, it is best to open a
network port for MySQL to use before beginning the installation. To do
this, first ensure that you are logged in as an Administrator, then go
to the `Control Panel' and double-click the `Windows Firewall' icon.
Choose the `Allow a program through Windows Firewall' option and click
the `Add port' button. Enter `MySQL' into the `Name' text box and
`3306' (or other port of your choice) into the `Port number' text box.
Also ensure that the `TCP' protocol radio button is selected. If you
wish, you can also limit access to the MySQL server by choosing the
`Change scope' button. Confirm your choices by clicking the `OK'
button. If you do not open a port prior to installation, you cannot
configure the MySQL server immediately after installation.
Additionally, when running the MySQL Installation Wizard on Windows
Vista or newer, ensure that you are logged in as a user with
administrative rights.

The process for starting the wizard depends on the contents of the
installation package you download. If there is a `setup.exe' file
present, double-click it to start the installation process. If there is
an `.msi' file present, double-click it to start the installation
process.

MySQL Installer Main Screen (Windows)

File: manual.info, Node: mysql-install-wizard-install-type, Next: mysql-install-wizard-custom-install, Prev: mysql-install-wizard-starting, Up: windows-install-wizard

3.10.2.3 Choosing an Installation Type
......................................

There are three installation types available: *Typical*, *Complete*, and
*Custom*.

MySQL Installer Setup type (Windows)

The *Typical* installation type installs the MySQL server, the *Note
`mysql': mysql. command-line client, and the command-line utilities.
The command-line clients and utilities include *Note `mysqldump':
mysqldump, *Note `myisamchk': myisamchk, and several other tools to
help you manage the MySQL server.

The *Complete* installation type installs all components included in
the installation package. The full installation package includes
components such as the embedded server library, the benchmark suite,
support scripts, and documentation.

The *Custom* installation type gives you complete control over which
packages you wish to install and the installation path that is used. See
*Note mysql-install-wizard-custom-install::, for more information on
performing a custom install.

If you choose the *Typical* or *Complete* installation types and click
the `Next' button, you advance to the confirmation screen to verify
your choices and begin the installation. If you choose the *Custom*
installation type and click the `Next' button, you advance to the
custom installation dialog, described in *Note
mysql-install-wizard-custom-install::.

File: manual.info, Node: mysql-install-wizard-custom-install, Next: mysql-install-wizard-confirmation-dialog, Prev: mysql-install-wizard-install-type, Up: windows-install-wizard

3.10.2.4 The Custom Installation Dialog
.......................................

If you wish to change the installation path or the specific components
that are installed by the MySQL Installation Wizard, choose the *Custom*
installation type.

MySQL Installer Custom Installation (Windows)

A tree view on the left side of the custom install dialog lists all
available components. Components that are not installed have a red `X'
icon; components that are installed have a gray icon. To change whether
a component is installed, click that component's icon and choose a new
option from the drop-down list that appears.

You can change the default installation path by clicking the
`Change...' button to the right of the displayed installation path.

After choosing your installation components and installation path,
click the `Next' button to advance to the confirmation dialog.

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3.10.2.5 The Confirmation Dialog
................................

Once you choose an installation type and optionally choose your
installation components, you advance to the confirmation dialog. Your
installation type and installation path are displayed for you to review.

MySQL Installer Installation Summary (Windows)

To install MySQL if you are satisfied with your settings, click the
`Install' button. To change your settings, click the `Back' button. To
exit the MySQL Installation Wizard without installing MySQL, click the
`Cancel' button.

After installation is complete, you have the option of registering with
the MySQL Web site. Registration gives you access to post in the MySQL
forums at forums.mysql.com (http://forums.mysql.com), along with the
ability to report bugs at bugs.mysql.com (http://bugs.mysql.com) and to
subscribe to our newsletter. The final screen of the installer provides
a summary of the installation and gives you the option to launch the
MySQL Configuration Wizard, which you can use to create a configuration
file, install the MySQL service, and configure security settings.

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3.10.2.6 Changes Made by MySQL Installation Wizard
..................................................

Once you click the `Install' button, the MySQL Installation Wizard
begins the installation process and makes certain changes to your
system which are described in the sections that follow.

*Changes to the Registry*

The MySQL Installation Wizard creates one Windows registry key in a
typical install situation, located in
`HKEY_LOCAL_MACHINE\SOFTWARE\MySQL AB'.

The MySQL Installation Wizard creates a key named after the major
version of the server that is being installed, such as `MySQL Server
5.0'. It contains two string values, `Location' and `Version'. The
`Location' string contains the path to the installation directory. In a
default installation it contains `C:\Program Files\MySQL\MySQL Server
5.0\'. The `Version' string contains the release number. For example,
for an installation of MySQL Server 5.0.93, the key contains a value of
`5.0.93'.

These registry keys are used to help external tools identify the
installed location of the MySQL server, preventing a complete scan of
the hard-disk to determine the installation path of the MySQL server.
The registry keys are not required to run the server, and if you
install MySQL using the `noinstall' Zip archive, the registry keys are
not created.

*Changes to the Start Menu*

The MySQL Installation Wizard creates a new entry in the Windows
`Start' menu under a common MySQL menu heading named after the major
version of MySQL that you have installed. For example, if you install
MySQL 5.0, the MySQL Installation Wizard creates a `MySQL Server 5.0'
section in the `Start' menu.

The following entries are created within the new `Start' menu section:

* `MySQL Command Line Client': This is a shortcut to the *Note
`mysql': mysql. command-line client and is configured to connect
as the `root' user. The shortcut prompts for a `root' user
password when you connect.

* `MySQL Server Instance Config Wizard': This is a shortcut to the
MySQL Configuration Wizard. Use this shortcut to configure a newly
installed server, or to reconfigure an existing server.

* `MySQL Documentation': This is a link to the MySQL server
documentation that is stored locally in the MySQL server
installation directory. This option is not available when the
MySQL server is installed using the Essentials installation
package.

*Changes to the File System*

The MySQL Installation Wizard by default installs the MySQL 5.0 server
to `C:\PROGRAM FILES\MySQL\MySQL Server 5.0', where PROGRAM FILES is
the default location for applications in your system, and 5.0 is the
major version of your MySQL server. This is the recommended location
for the MySQL server, replacing the former default location `C:\mysql'.

By default, all MySQL applications are stored in a common directory at
`C:\PROGRAM FILES\MySQL', where PROGRAM FILES is the default location
for applications in your Windows installation. A typical MySQL
installation on a developer machine might look like this:

C:\Program Files\MySQL\MySQL Server 5.0
C:\Program Files\MySQL\MySQL Workbench 5.1 OSS

This approach makes it easier to manage and maintain all MySQL
applications installed on a particular system.

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3.10.2.7 Upgrading MySQL with the Installation Wizard
.....................................................

The MySQL Installation Wizard can perform server upgrades automatically
using the upgrade capabilities of MSI. That means you do not need to
remove a previous installation manually before installing a new
release. The installer automatically shuts down and removes the
previous MySQL service before installing the new version.

Automatic upgrades are available only when upgrading between
installations that have the same major and minor version numbers. For
example, you can upgrade automatically from MySQL 5.0.5 to MySQL 5.0.6,
but not from MySQL 4.1 to MySQL 5.0.

See *Note windows-upgrading::.

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3.10.3 MySQL Server Instance Configuration Wizard
-------------------------------------------------

* Menu:

* mysql-config-wizard-starting:: Starting the MySQL Server Instance Configuration Wizard
* mysql-config-wizard-maintenance:: Choosing a Maintenance Option
* mysql-config-wizard-configuration-type:: Choosing a Configuration Type
* mysql-config-wizard-server-type:: The Server Type Dialog
* mysql-config-wizard-database-usage:: The Database Usage Dialog
* mysql-config-wizard-tablespace:: The InnoDB Tablespace Dialog
* mysql-config-wizard-connections:: The Concurrent Connections Dialog
* mysql-config-wizard-networking:: The Networking and Strict Mode Options Dialog
* mysql-config-wizard-character-set:: The Character Set Dialog
* mysql-config-wizard-service:: The Service Options Dialog
* mysql-config-wizard-security:: The Security Options Dialog
* mysql-config-wizard-confirmation:: The Confirmation Dialog

The MySQL Server Instance Configuration Wizard helps automate the
process of configuring your server. It creates a custom MySQL
configuration file (`my.ini' or `my.cnf') by asking you a series of
questions and then applying your responses to a template to generate the
configuration file that is tuned to your installation.

The MySQL Server Instance Configuration Wizard is included with the
MySQL 5.0 server. The MySQL Server Instance Configuration Wizard is
only available for Windows.

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3.10.3.1 Starting the MySQL Server Instance Configuration Wizard
................................................................

The MySQL Server Instance Configuration Wizard is normally started as
part of the installation process. You should only need to run the MySQL
Server Instance Configuration Wizard again when you need to change the
configuration parameters of your server.

If you chose not to open a port prior to installing MySQL on Windows
Vista or newer, you can choose to use the MySQL Server Configuration
Wizard after installation. However, you must open a port in the Windows
Firewall. To do this see the instructions given in *Note
mysql-install-wizard-starting::. Rather than opening a port, you also
have the option of adding MySQL as a program that bypasses the Windows
Firewall. One or the other option is sufficient--you need not do both.
Additionally, when running the MySQL Server Configuration Wizard on
Windows Vista or newer, ensure that you are logged in as a user with
administrative rights.

MySQL Server Instance Configuration Wizard

You can launch the MySQL Configuration Wizard by clicking the `MySQL
Server Instance Config Wizard' entry in the `MySQL' section of the
Windows `Start' menu.

Alternatively, you can navigate to the `bin' directory of your MySQL
installation and launch the `MySQLInstanceConfig.exe' file directly.

The MySQL Server Instance Configuration Wizard places the `my.ini' file
in the installation directory for the MySQL server. This helps
associate configuration files with particular server instances.

To ensure that the MySQL server knows where to look for the `my.ini'
file, an argument similar to this is passed to the MySQL server as part
of the service installation:

--defaults-file="C:\PROGRAM FILES\MYSQL\MYSQL SERVER 5.0\my.ini"

Here, C:\PROGRAM FILES\MYSQL\MYSQL SERVER 5.0 is replaced with the
installation path to the MySQL Server. The `--defaults-file' option
instructs the MySQL server to read the specified file for configuration
options when it starts.

Apart from making changes to the `my.ini' file by running the MySQL
Server Instance Configuration Wizard again, you can modify it by
opening it with a text editor and making any necessary changes. You can
also modify the server configuration with the
http://www.mysql.com/products/administrator/ utility. For more
information about server configuration, see *Note server-options::.

MySQL clients and utilities such as the *Note `mysql': mysql. and
*Note `mysqldump': mysqldump. command-line clients are not able to
locate the `my.ini' file located in the server installation directory.
To configure the client and utility applications, create a new `my.ini'
file in the Windows installation directory (for example, `C:\WINDOWS').

Under Windows Server 2003, Windows Server 2000 and Windows XP, MySQL
Server Instance Configuration Wizard will configure MySQL to work as a
Windows service. To start and stop MySQL you use the `Services'
application that is supplied as part of the Windows Administrator Tools.

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3.10.3.2 Choosing a Maintenance Option
......................................

If the MySQL Server Instance Configuration Wizard detects an existing
configuration file, you have the option of either reconfiguring your
existing server, or removing the server instance by deleting the
configuration file and stopping and removing the MySQL service.

To reconfigure an existing server, choose the `Re-configure Instance'
option and click the `Next' button. Any existing configuration file is
not overwritten, but renamed (within the same directory) using a
timestamp (Windows) or sequential number (Linux). To remove the
existing server instance, choose the `Remove Instance' option and click
the `Next' button.

If you choose the `Remove Instance' option, you advance to a
confirmation window. Click the `Execute' button. The MySQL Server
Configuration Wizard stops and removes the MySQL service, and then
deletes the configuration file. The server installation and its `data'
folder are not removed.

If you choose the `Re-configure Instance' option, you advance to the
`Configuration Type' dialog where you can choose the type of
installation that you wish to configure.

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3.10.3.3 Choosing a Configuration Type
......................................

When you start the MySQL Server Instance Configuration Wizard for a new
MySQL installation, or choose the `Re-configure Instance' option for an
existing installation, you advance to the `Configuration Type' dialog.

MySQL Server Instance Configuration Wizard: Configuration Type

There are two configuration types available: `Detailed Configuration'
and `Standard Configuration'. The `Standard Configuration' option is
intended for new users who want to get started with MySQL quickly
without having to make many decisions about server configuration. The
`Detailed Configuration' option is intended for advanced users who want
more fine-grained control over server configuration.

If you are new to MySQL and need a server configured as a single-user
developer machine, the `Standard Configuration' should suit your needs.
Choosing the `Standard Configuration' option causes the MySQL
Configuration Wizard to set all configuration options automatically
with the exception of `Service Options' and `Security Options'.

The `Standard Configuration' sets options that may be incompatible with
systems where there are existing MySQL installations. If you have an
existing MySQL installation on your system in addition to the
installation you wish to configure, the `Detailed Configuration' option
is recommended.

To complete the `Standard Configuration', please refer to the sections
on `Service Options' and `Security Options' in *Note
mysql-config-wizard-service::, and *Note
mysql-config-wizard-security::, respectively.

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3.10.3.4 The Server Type Dialog
...............................

There are three different server types available to choose from. The
server type that you choose affects the decisions that the MySQL Server
Instance Configuration Wizard makes with regard to memory, disk, and
processor usage.

MySQL Server Instance Configuration Wizard: Server Type

* `Developer Machine': Choose this option for a typical desktop
workstation where MySQL is intended only for personal use. It is
assumed that many other desktop applications are running. The
MySQL server is configured to use minimal system resources.

* `Server Machine': Choose this option for a server machine where
the MySQL server is running alongside other server applications
such as FTP, email, and Web servers. The MySQL server is
configured to use a moderate portion of the system resources.

* `Dedicated MySQL Server Machine': Choose this option for a server
machine that is intended to run only the MySQL server. It is
assumed that no other applications are running. The MySQL server
is configured to use all available system resources.

*Note*:

By selecting one of the preconfigured configurations, the values and
settings of various options in your `my.cnf' or `my.ini' will be
altered accordingly. The default values and options as described in the
reference manual may therefore be different to the options and values
that were created during the execution of the configuration wizard.

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3.10.3.5 The Database Usage Dialog
..................................

The `Database Usage' dialog enables you to indicate the storage engines
that you expect to use when creating MySQL tables. The option you
choose determines whether the `InnoDB' storage engine is available and
what percentage of the server resources are available to `InnoDB'.

MySQL Server Instance Configuration Wizard: Usage Dialog

* `Multifunctional Database': This option enables both the `InnoDB'
and `MyISAM' storage engines and divides resources evenly between
the two. This option is recommended for users who use both storage
engines on a regular basis.

* `Transactional Database Only': This option enables both the
`InnoDB' and `MyISAM' storage engines, but dedicates most server
resources to the `InnoDB' storage engine. This option is
recommended for users who use `InnoDB' almost exclusively and make
only minimal use of `MyISAM'.

* `Non-Transactional Database Only': This option disables the
`InnoDB' storage engine completely and dedicates all server
resources to the `MyISAM' storage engine. This option is
recommended for users who do not use `InnoDB'.

The Configuration Wizard uses a template to generate the server
configuration file. The `Database Usage' dialog sets one of the
following option strings:

Multifunctional Database: MIXED
Transactional Database Only: INNODB
Non-Transactional Database Only: MYISAM

When these options are processed through the default template
(my-template.ini) the result is:

Multifunctional Database:
default-storage-engine=InnoDB
_myisam_pct=50

Transactional Database Only:
default-storage-engine=InnoDB
_myisam_pct=5

Non-Transactional Database Only:
default-storage-engine=MyISAM
_myisam_pct=100
skip-innodb

The `_myisam_pct' value is used to calculate the percentage of
resources dedicated to `MyISAM'. The remaining resources are allocated
to `InnoDB'.

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3.10.3.6 The InnoDB Tablespace Dialog
.....................................

Some users may want to locate the `InnoDB' tablespace files in a
different location than the MySQL server data directory. Placing the
tablespace files in a separate location can be desirable if your system
has a higher capacity or higher performance storage device available,
such as a RAID storage system.

MySQL Server Instance Configuration Wizard: InnoDB Data Tablespace

To change the default location for the `InnoDB' tablespace files,
choose a new drive from the drop-down list of drive letters and choose
a new path from the drop-down list of paths. To create a custom path,
click the `...' button.

If you are modifying the configuration of an existing server, you must
click the `Modify' button before you change the path. In this situation
you must move the existing tablespace files to the new location
manually before starting the server.

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3.10.3.7 The Concurrent Connections Dialog
..........................................

To prevent the server from running out of resources, it is important to
limit the number of concurrent connections to the MySQL server that can
be established. The `Concurrent Connections' dialog enables you to
choose the expected usage of your server, and sets the limit for
concurrent connections accordingly. It is also possible to set the
concurrent connection limit manually.

MySQL Server Instance Configuration Wizard: Connections

* `Decision Support (DSS)/OLAP': Choose this option if your server
does not require a large number of concurrent connections. The
maximum number of connections is set at 100, with an average of 20
concurrent connections assumed.

* `Online Transaction Processing (OLTP)': Choose this option if your
server requires a large number of concurrent connections. The
maximum number of connections is set at 500.

* `Manual Setting': Choose this option to set the maximum number of
concurrent connections to the server manually. Choose the number
of concurrent connections from the drop-down box provided, or
enter the maximum number of connections into the drop-down box if
the number you desire is not listed.

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3.10.3.8 The Networking and Strict Mode Options Dialog
......................................................

Use the `Networking Options' dialog to enable or disable TCP/IP
networking and to configure the port number that is used to connect to
the MySQL server.

MySQL Server Instance Configuration Wizard: Network Configuration

TCP/IP networking is enabled by default. To disable TCP/IP networking,
uncheck the box next to the `Enable TCP/IP Networking' option.

Port 3306 is used by default. To change the port used to access MySQL,
choose a new port number from the drop-down box or type a new port
number directly into the drop-down box. If the port number you choose
is in use, you are prompted to confirm your choice of port number.

Set the `Server SQL Mode' to either enable or disable strict mode.
Enabling strict mode (default) makes MySQL behave more like other
database management systems. _If you run applications that rely on
MySQL's old `forgiving' behavior, make sure to either adapt those
applications or to disable strict mode._ For more information about
strict mode, see *Note server-sql-mode::.

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3.10.3.9 The Character Set Dialog
.................................

The MySQL server supports multiple character sets and it is possible to
set a default server character set that is applied to all tables,
columns, and databases unless overridden. Use the `Character Set'
dialog to change the default character set of the MySQL server.

MySQL Server Instance Configuration Wizard: Character Set

* `Standard Character Set': Choose this option if you want to use
`latin1' as the default server character set. `latin1' is used for
English and many Western European languages.

* `Best Support For Multilingualism': Choose this option if you want
to use `utf8' as the default server character set. This is a
Unicode character set that can store characters from many
different languages.

* `Manual Selected Default Character Set / Collation': Choose this
option if you want to pick the server's default character set
manually. Choose the desired character set from the provided
drop-down list.

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3.10.3.10 The Service Options Dialog
....................................

On Windows platforms, the MySQL server can be installed as a Windows
service. When installed this way, the MySQL server can be started
automatically during system startup, and even restarted automatically
by Windows in the event of a service failure.

The MySQL Server Instance Configuration Wizard installs the MySQL
server as a service by default, using the service name `MySQL'. If you
do not wish to install the service, uncheck the box next to the
`Install As Windows Service' option. You can change the service name by
picking a new service name from the drop-down box provided or by
entering a new service name into the drop-down box.

*Note*:

Service names can include any legal character except forward (`/') or
backward (`\') slashes, and must be less than 256 characters long.

*Warning*:

If you are installing multiple versions of MySQL onto the same machine,
you _must_ choose a different service name for each version that you
install. If you do not choose a different service for each installed
version then the service manager information will be inconsistent and
this will cause problems when you try to uninstall a previous version.

If you have already installed multiple versions using the same service
name, you must manually edit the contents of the
`HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services' parameters
within the Windows registry to update the association of the service
name with the correct server version.

Typically, when installing multiple versions you create a service name
based on the version information. For example, you might install MySQL
5.x as `mysql5', or specific versions such as MySQL 5.0.56 as
`mysql50056'.

To install the MySQL server as a service but not have it started
automatically at startup, uncheck the box next to the `Launch the MySQL
Server Automatically' option.

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3.10.3.11 The Security Options Dialog
.....................................

_It is strongly recommended that you set a `root' password for your
MySQL server_, and the MySQL Server Instance Configuration Wizard
requires by default that you do so. If you do not wish to set a `root'
password, uncheck the box next to the `Modify Security Settings' option.

MySQL Server Instance Configuration Wizard: Security

To set the `root' password, enter the desired password into both the
`New root password' and `Confirm' boxes. If you are reconfiguring an
existing server, you need to enter the existing `root' password into the
`Current root password' box.

To permit `root' logins from across the network, check the box next to
the `Enable root access from remote machines' option. This decreases
the security of your `root' account.

To create an anonymous user account, check the box next to the `Create
An Anonymous Account' option. Creating an anonymous account can
decrease server security and cause login and permission difficulties.
For this reason, it is not recommended.

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3.10.3.12 The Confirmation Dialog
.................................

The final dialog in the MySQL Server Instance Configuration Wizard is
the `Confirmation Dialog'. To start the configuration process, click the
`Execute' button. To return to a previous dialog, click the `Back'
button. To exit the MySQL Server Instance Configuration Wizard without
configuring the server, click the `Cancel' button.

MySQL Server Instance Configuration Wizard: Confirmation

After you click the `Execute' button, the MySQL Server Instance
Configuration Wizard performs a series of tasks and displays the
progress onscreen as the tasks are performed.

The MySQL Server Instance Configuration Wizard first determines
configuration file options based on your choices using a template
prepared by MySQL developers and engineers. This template is named
`my-template.ini' and is located in your server installation directory.

The MySQL Configuration Wizard then writes these options to the
corresponding configuration file.

If you chose to create a service for the MySQL server, the MySQL Server
Instance Configuration Wizard creates and starts the service. If you
are reconfiguring an existing service, the MySQL Server Instance
Configuration Wizard restarts the service to apply your configuration
changes.

If you chose to set a `root' password, the MySQL Configuration Wizard
connects to the server, sets your new `root' password, and applies any
other security settings you may have selected.

After the MySQL Server Instance Configuration Wizard has completed its
tasks, it displays a summary. Click the `Finish' button to exit the
MySQL Server Configuration Wizard.

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3.10.4 Installing MySQL from a Noinstall Zip Archive
----------------------------------------------------

* Menu:

* windows-extract-archive:: Extracting the Install Archive
* windows-create-option-file:: Creating an Option File
* windows-select-server:: Selecting a MySQL Server Type
* windows-server-first-start:: Starting the Server for the First Time
* windows-start-command-line:: Starting MySQL from the Windows Command Line
* mysql-installation-windows-path:: Customizing the PATH for MySQL Tools
* windows-start-service:: Starting MySQL as a Windows Service
* windows-testing:: Testing The MySQL Installation

Users who are installing from the Noinstall package can use the
instructions in this section to manually install MySQL. The process for
installing MySQL from a Zip archive is as follows:

1. Extract the archive to the desired install directory

2. Create an option file

3. Choose a MySQL server type

4. Start the MySQL server

5. Secure the default user accounts

This process is described in the sections that follow.

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3.10.4.1 Extracting the Install Archive
.......................................

To install MySQL manually, do the following:

1. If you are upgrading from a previous version please refer to *Note
windows-upgrading::, before beginning the upgrade process.

2. Make sure that you are logged in as a user with administrator
privileges.

3. Choose an installation location. Traditionally, the MySQL server
is installed in `C:\mysql'. The MySQL Installation Wizard installs
MySQL under `C:\Program Files\MySQL'. If you do not install MySQL
at `C:\mysql', you must specify the path to the install directory
during startup or in an option file. See *Note
windows-create-option-file::.

4. Extract the install archive to the chosen installation location
using your preferred Zip archive tool. Some tools may extract the
archive to a folder within your chosen installation location. If
this occurs, you can move the contents of the subfolder into the
chosen installation location.

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3.10.4.2 Creating an Option File
................................

If you need to specify startup options when you run the server, you can
indicate them on the command line or place them in an option file. For
options that are used every time the server starts, you may find it
most convenient to use an option file to specify your MySQL
configuration. This is particularly true under the following
circumstances:

* The installation or data directory locations are different from
the default locations (`C:\Program Files\MySQL\MySQL Server 5.0'
and `C:\Program Files\MySQL\MySQL Server 5.0\data').

* You need to tune the server settings.

When the MySQL server starts on Windows, it looks for option files in
several locations, such as the Windows directory, `C:\', and the MySQL
installation directory (for the full list of locations, see *Note
option-files::). The Windows directory typically is named something
like `C:\WINDOWS'. You can determine its exact location from the value
of the `WINDIR' environment variable using the following command:

shell> echo %WINDIR%

MySQL looks for options in each location first in the `my.ini' file,
and then in the `my.cnf' file. However, to avoid confusion, it is best
if you use only one file. If your PC uses a boot loader where `C:' is
not the boot drive, your only option is to use the `my.ini' file.
Whichever option file you use, it must be a plain text file.

You can also make use of the example option files included with your
MySQL distribution; see *Note option-files-preconfigured::.

An option file can be created and modified with any text editor, such
as Notepad. For example, if MySQL is installed in `E:\mysql' and the
data directory is in `E:\mydata\data', you can create an option file
containing a `[mysqld]' section to specify values for the `basedir' and
`datadir' options:

[mysqld]
# set basedir to your installation path
basedir=E:/mysql
# set datadir to the location of your data directory
datadir=E:/mydata/data

Note that Windows path names are specified in option files using
(forward) slashes rather than backslashes. If you do use backslashes,
double them:

[mysqld]
# set basedir to your installation path
basedir=E:\\mysql
# set datadir to the location of your data directory
datadir=E:\\mydata\\data

The rules for use of backslash in option file values are given in *Note
option-files::.

On Windows, the MySQL installer places the data directory directly
under the directory where you install MySQL. If you would like to use a
data directory in a different location, you should copy the entire
contents of the `data' directory to the new location. For example, if
MySQL is installed in `C:\Program Files\MySQL\MySQL Server 5.0', the
data directory is by default in `C:\Program Files\MySQL\MySQL Server
5.0\data'. If you want to use `E:\mydata' as the data directory instead,
you must do two things:

1. Move the entire `data' directory and all of its contents from
`C:\Program Files\MySQL\MySQL Server 5.0\data' to `E:\mydata'.

2. Use a `--datadir' option to specify the new data directory
location each time you start the server.

File: manual.info, Node: windows-select-server, Next: windows-server-first-start, Prev: windows-create-option-file, Up: windows-install-archive

3.10.4.3 Selecting a MySQL Server Type
......................................

The following table shows the available servers for Windows in MySQL
5.0.

Binary Description
*Note Optimized binary with named-pipe support
`mysqld-nt':
mysqld.
*Note Optimized binary without named-pipe support
`mysqld':
mysqld.
*Note Like *Note `mysqld-nt': mysqld, but compiled with full
`mysqld-debug':debugging and automatic memory allocation checking
mysqld.

All of the preceding binaries are optimized for modern Intel
processors, but should work on any Intel i386-class or higher processor.

Each of the servers in a distribution support the same set of storage
engines. The *Note `SHOW ENGINES': show-engines. statement displays
which engines a given server supports.

All Windows MySQL 5.0 servers have support for symbolic linking of
database directories.

MySQL supports TCP/IP on all Windows platforms. MySQL servers on
Windows support named pipes as indicated in the following list.
However, the default is to use TCP/IP regardless of platform. (Named
pipes are slower than TCP/IP in many Windows configurations.)

Use of named pipes is subject to these conditions:

* Named pipes are enabled only if you start the server with the
`--enable-named-pipe' option. It is necessary to use this option
explicitly because some users have experienced problems with
shutting down the MySQL server when named pipes were used.

* Named-pipe connections are permitted only by the *Note
`mysqld-nt': mysqld. and *Note `mysqld-debug': mysqld. servers.

*Note*:

Most of the examples in this manual use *Note `mysqld': mysqld. as the
server name. If you choose to use a different server, such as *Note
`mysqld-nt': mysqld, make the appropriate substitutions in the commands
that are shown in the examples.

File: manual.info, Node: windows-server-first-start, Next: windows-start-command-line, Prev: windows-select-server, Up: windows-install-archive

3.10.4.4 Starting the Server for the First Time
...............................................

This section gives a general overview of starting the MySQL server. The
following sections provide more specific information for starting the
MySQL server from the command line or as a Windows service.

The information here applies primarily if you installed MySQL using the
`Noinstall' version, or if you wish to configure and test MySQL
manually rather than with the GUI tools.

The examples in these sections assume that MySQL is installed under the
default location of `C:\Program Files\MySQL\MySQL Server 5.0'. Adjust
the path names shown in the examples if you have MySQL installed in a
different location.

Clients have two options. They can use TCP/IP, or they can use a named
pipe if the server supports named-pipe connections.

MySQL for Windows also supports shared-memory connections if the server
is started with the `--shared-memory' option. Clients can connect
through shared memory by using the `--protocol=MEMORY' option.

For information about which server binary to run, see *Note
windows-select-server::.

Testing is best done from a command prompt in a console window (or `DOS
window'). In this way you can have the server display status messages
in the window where they are easy to see. If something is wrong with
your configuration, these messages make it easier for you to identify
and fix any problems.

To start the server, enter this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --console

For a server that includes `InnoDB' support, you should see the
messages similar to those following as it starts (the path names and
sizes may differ):

InnoDB: The first specified datafile c:\ibdata\ibdata1 did not exist:
InnoDB: a new database to be created!
InnoDB: Setting file c:\ibdata\ibdata1 size to 209715200
InnoDB: Database physically writes the file full: wait...
InnoDB: Log file c:\iblogs\ib_logfile0 did not exist: new to be created
InnoDB: Setting log file c:\iblogs\ib_logfile0 size to 31457280
InnoDB: Log file c:\iblogs\ib_logfile1 did not exist: new to be created
InnoDB: Setting log file c:\iblogs\ib_logfile1 size to 31457280
InnoDB: Log file c:\iblogs\ib_logfile2 did not exist: new to be created
InnoDB: Setting log file c:\iblogs\ib_logfile2 size to 31457280
InnoDB: Doublewrite buffer not found: creating new
InnoDB: Doublewrite buffer created
InnoDB: creating foreign key constraint system tables
InnoDB: foreign key constraint system tables created
011024 10:58:25 InnoDB: Started

When the server finishes its startup sequence, you should see something
like this, which indicates that the server is ready to service client
connections:

mysqld: ready for connections
Version: '5.0.93' socket: '' port: 3306

The server continues to write to the console any further diagnostic
output it produces. You can open a new console window in which to run
client programs.

If you omit the `--console' option, the server writes diagnostic output
to the error log in the data directory (`C:\Program Files\MySQL\MySQL
Server 5.0\data' by default). The error log is the file with the `.err'
extension.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

File: manual.info, Node: windows-start-command-line, Next: mysql-installation-windows-path, Prev: windows-server-first-start, Up: windows-install-archive

3.10.4.5 Starting MySQL from the Windows Command Line
.....................................................

The MySQL server can be started manually from the command line. This
can be done on any version of Windows.

To start the *Note `mysqld': mysqld. server from the command line, you
should start a console window (or `DOS window') and enter this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld"

The path to *Note `mysqld': mysqld. may vary depending on the install
location of MySQL on your system.

You can stop the MySQL server by executing this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" -u root shutdown

*Note*:

If the MySQL `root' user account has a password, you need to invoke
*Note `mysqladmin': mysqladmin. with the `-p' option and supply the
password when prompted.

This command invokes the MySQL administrative utility *Note
`mysqladmin': mysqladmin. to connect to the server and tell it to shut
down. The command connects as the MySQL `root' user, which is the
default administrative account in the MySQL grant system. Note that
users in the MySQL grant system are wholly independent from any login
users under Windows.

If *Note `mysqld': mysqld. doesn't start, check the error log to see
whether the server wrote any messages there to indicate the cause of
the problem. The error log is located in the `C:\Program
Files\MySQL\MySQL Server 5.0\data' directory. It is the file with a
suffix of `.err'. You can also try to start the server as *Note `mysqld
--console': mysqld.; in this case, you may get some useful information
on the screen that may help solve the problem.

The last option is to start *Note `mysqld': mysqld. with the
`--standalone' and `--debug' options. In this case, *Note `mysqld':
mysqld. writes a log file `C:\mysqld.trace' that should contain the
reason why *Note `mysqld': mysqld. doesn't start. See MySQL Internals:
Porting (http://forge.mysql.com/wiki/MySQL_Internals_Porting).

Use *Note `mysqld --verbose --help': mysqld. to display all the options
that *Note `mysqld': mysqld. supports.

File: manual.info, Node: mysql-installation-windows-path, Next: windows-start-service, Prev: windows-start-command-line, Up: windows-install-archive

3.10.4.6 Customizing the PATH for MySQL Tools
.............................................

To make it easier to invoke MySQL programs, you can add the path name
of the MySQL `bin' directory to your Windows system `PATH' environment
variable:

* On the Windows desktop, right-click the `My Computer' icon, and
select `Properties'.

* Next select the `Advanced' tab from the `System Properties' menu
that appears, and click the `Environment Variables' button.

* Under `System Variables', select `Path', and then click the `Edit'
button. The `Edit System Variable' dialogue should appear.

*Note*:

There must be a semicolon separating this path from any values
present in this field.

Dismiss this dialogue, and each dialogue in turn, by clicking `OK'
until all of the dialogues that were opened have been dismissed.
You should now be able to invoke any MySQL executable program by
typing its name at the DOS prompt from any directory on the system,
without having to supply the path. This includes the servers, the
*Note `mysql': mysql. client, and all MySQL command-line utilities
such as *Note `mysqladmin': mysqladmin. and *Note `mysqldump':
mysqldump.

You should not add the MySQL `bin' directory to your Windows
`PATH' if you are running multiple MySQL servers on the same
machine.

*Warning*:

You must exercise great care when editing your system `PATH' by hand;
accidental deletion or modification of any portion of the existing
`PATH' value can leave you with a malfunctioning or even unusable
system.

File: manual.info, Node: windows-start-service, Next: windows-testing, Prev: mysql-installation-windows-path, Up: windows-install-archive

3.10.4.7 Starting MySQL as a Windows Service
............................................

On Windows, the recommended way to run MySQL is to install it as a
Windows service, whereby MySQL starts and stops automatically when
Windows starts and stops. A MySQL server installed as a service can
also be controlled from the command line using `NET' commands, or with
the graphical `Services' utility. Generally, to install MySQL as a
Windows service you should be logged in using an account that has
administrator rights.

The `Services' utility (the Windows `Service Control Manager') can be
found in the Windows Control Panel (under `Administrative Tools' on
Windows 2000, XP, Vista, and Server 2003). To avoid conflicts, it is
advisable to close the `Services' utility while performing server
installation or removal operations from the command line.

Before installing MySQL as a Windows service, you should first stop the
current server if it is running by using the following command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin"
-u root shutdown

*Note*:

If the MySQL `root' user account has a password, you need to invoke
*Note `mysqladmin': mysqladmin. with the `-p' option and supply the
password when prompted.

Install the server as a service using this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --install

The service-installation command does not start the server.
Instructions for that are given later in this section.

To make it easier to invoke MySQL programs, you can add the path name
of the MySQL `bin' directory to your Windows system `PATH' environment
variable:

* On the Windows desktop, right-click the `My Computer' icon, and
select `Properties'.

* Next select the `Advanced' tab from the `System Properties' menu
that appears, and click the `Environment Variables' button.

* Under `System Variables', select `Path', and then click the `Edit'
button. The `Edit System Variable' dialogue should appear.

* Place your cursor at the end of the text appearing in the space
marked `Variable Value'. (Use the `End' key to ensure that your
cursor is positioned at the very end of the text in this space.)
Then enter the complete path name of your MySQL `bin' directory
(for example, `C:\Program Files\MySQL\MySQL Server 5.0\bin'), Note
that there should be a semicolon separating this path from any
values present in this field. Dismiss this dialogue, and each
dialogue in turn, by clicking `OK' until all of the dialogues that
were opened have been dismissed. You should now be able to invoke
any MySQL executable program by typing its name at the DOS prompt
from any directory on the system, without having to supply the
path. This includes the servers, the *Note `mysql': mysql. client,
and all MySQL command-line utilities such as *Note `mysqladmin':
mysqladmin. and *Note `mysqldump': mysqldump.

You should not add the MySQL `bin' directory to your Windows
`PATH' if you are running multiple MySQL servers on the same
machine.

*Warning*:

The following additional arguments can be used in MySQL 5.0 when
installing the service:

* You can specify a service name immediately following the
`--install' option. The default service name is `MySQL'.

* If a service name is given, it can be followed by a single option.
By convention, this should be `--defaults-file=FILE_NAME' to
specify the name of an option file from which the server should
read options when it starts.

The use of a single option other than `--defaults-file' is possible
but discouraged. `--defaults-file' is more flexible because it
enables you to specify multiple startup options for the server by
placing them in the named option file. Also, in MySQL 5.0, use of
an option different from `--defaults-file' is not supported until
5.0.3.

* As of MySQL 5.0.1, you can also specify a `--local-service' option
following the service name. This causes the server to run using the
`LocalService' Windows account that has limited system privileges.
This account is available only for Windows XP or newer. If both
`--defaults-file' and `--local-service' are given following the
service name, they can be in any order.

For a MySQL server that is installed as a Windows service, the
following rules determine the service name and option files that the
server uses:

* If the service-installation command specifies no service name or
the default service name (`MySQL') following the `--install'
option, the server uses the a service name of `MySQL' and reads
options from the `[mysqld]' group in the standard option files.

* If the service-installation command specifies a service name other
than `MySQL' following the `--install' option, the server uses that
service name. It reads options from the `[mysqld]' group and the
group that has the same name as the service in the standard option
files. This enables you to use the `[mysqld]' group for options
that should be used by all MySQL services, and an option group
with the service name for use by the server installed with that
service name.

* If the service-installation command specifies a `--defaults-file'
option after the service name, the server reads options only from
the `[mysqld]' group of the named file and ignores the standard
option files.

As a more complex example, consider the following command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld"
--install MySQL --defaults-file=C:\my-opts.cnf

Here, the default service name (`MySQL') is given after the `--install'
option. If no `--defaults-file' option had been given, this command
would have the effect of causing the server to read the `[mysqld]'
group from the standard option files. However, because the
`--defaults-file' option is present, the server reads options from the
`[mysqld]' option group, and only from the named file.

You can also specify options as Start parameters in the Windows
`Services' utility before you start the MySQL service.

Once a MySQL server has been installed as a service, Windows starts the
service automatically whenever Windows starts. The service also can be
started immediately from the `Services' utility, or by using a `NET
START MySQL' command. The `NET' command is not case sensitive.

When run as a service, *Note `mysqld': mysqld. has no access to a
console window, so no messages can be seen there. If *Note `mysqld':
mysqld. does not start, check the error log to see whether the server
wrote any messages there to indicate the cause of the problem. The
error log is located in the MySQL data directory (for example,
`C:\Program Files\MySQL\MySQL Server 5.0\data'). It is the file with a
suffix of `.err'.

When a MySQL server has been installed as a service, and the service is
running, Windows stops the service automatically when Windows shuts
down. The server also can be stopped manually by using the `Services'
utility, the `NET STOP MySQL' command, or the *Note `mysqladmin
shutdown': mysqladmin. command.

You also have the choice of installing the server as a manual service
if you do not wish for the service to be started automatically during
the boot process. To do this, use the `--install-manual' option rather
than the `--install' option:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --install-manual

To remove a server that is installed as a service, first stop it if it
is running by executing `NET STOP MySQL'. Then use the `--remove'
option to remove it:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld" --remove

If *Note `mysqld': mysqld. is not running as a service, you can start
it from the command line. For instructions, see *Note
windows-start-command-line::.

Please see *Note windows-troubleshooting::, if you encounter
difficulties during installation.

File: manual.info, Node: windows-testing, Prev: windows-start-service, Up: windows-install-archive

3.10.4.8 Testing The MySQL Installation
.......................................

You can test whether the MySQL server is working by executing any of
the following commands:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqlshow"
shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqlshow" -u root mysql
shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" version status proc
shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysql" test

If *Note `mysqld': mysqld. is slow to respond to TCP/IP connections
from client programs, there is probably a problem with your DNS. In
this case, start *Note `mysqld': mysqld. with the `--skip-name-resolve'
option and use only `localhost' and IP addresses in the `Host' column
of the MySQL grant tables.

You can force a MySQL client to use a named-pipe connection rather than
TCP/IP by specifying the `--pipe' or `--protocol=PIPE' option, or by
specifying `.' (period) as the host name. Use the `--socket' option to
specify the name of the pipe if you do not want to use the default pipe
name.

Note that if you have set a password for the `root' account, deleted
the anonymous account, or created a new user account, then you must use
the appropriate `-u' and `-p' options with the commands shown above to
connect with the MySQL Server. See *Note connecting::.

For more information about *Note `mysqlshow': mysqlshow, see *Note
mysqlshow::.

File: manual.info, Node: windows-troubleshooting, Next: windows-upgrading, Prev: windows-install-archive, Up: windows-installation

3.10.5 Troubleshooting a MySQL Installation Under Windows
---------------------------------------------------------

When installing and running MySQL for the first time, you may encounter
certain errors that prevent the MySQL server from starting. The purpose
of this section is to help you diagnose and correct some of these
errors.

Your first resource when troubleshooting server issues is the error
log. The MySQL server uses the error log to record information relevant
to the error that prevents the server from starting. The error log is
located in the data directory specified in your `my.ini' file. The
default data directory location is `C:\Program Files\MySQL\MySQL Server
5.0\data'. See *Note error-log::.

Another source of information regarding possible errors is the console
messages displayed when the MySQL service is starting. Use the `NET
START MySQL' command from the command line after installing *Note
`mysqld': mysqld. as a service to see any error messages regarding the
starting of the MySQL server as a service. See *Note
windows-start-service::.

The following examples show other common error messages you may
encounter when installing MySQL and starting the server for the first
time:

* If the MySQL server cannot find the `mysql' privileges database or
other critical files, you may see these messages:

System error 1067 has occurred.
Fatal error: Can't open privilege tables: Table 'mysql.host' doesn't exist

These messages often occur when the MySQL base or data directories
are installed in different locations than the default locations
(`C:\Program Files\MySQL\MySQL Server 5.0' and `C:\Program
Files\MySQL\MySQL Server 5.0\data', respectively).

This situation may occur when MySQL is upgraded and installed to a
new location, but the configuration file is not updated to reflect
the new location. In addition, there may be old and new
configuration files that conflict. Be sure to delete or rename any
old configuration files when upgrading MySQL.

If you have installed MySQL to a directory other than `C:\Program
Files\MySQL\MySQL Server 5.0', you need to ensure that the MySQL
server is aware of this through the use of a configuration
(`my.ini') file. The `my.ini' file needs to be located in your
Windows directory, typically `C:\WINDOWS'. You can determine its
exact location from the value of the `WINDIR' environment variable
by issuing the following command from the command prompt:

shell> echo %WINDIR%

An option file can be created and modified with any text editor,
such as Notepad. For example, if MySQL is installed in `E:\mysql'
and the data directory is `D:\MySQLdata', you can create the option
file and set up a `[mysqld]' section to specify values for the
`basedir' and `datadir' options:

[mysqld]
# set basedir to your installation path
basedir=E:/mysql
# set datadir to the location of your data directory
datadir=D:/MySQLdata

Note that Windows path names are specified in option files using
(forward) slashes rather than backslashes. If you do use
backslashes, double them:

[mysqld]
# set basedir to your installation path
basedir=C:\\Program Files\\MySQL\\MySQL Server 5.0
# set datadir to the location of your data directory
datadir=D:\\MySQLdata

The rules for use of backslash in option file values are given in
*Note option-files::.

If you change the `datadir' value in your MySQL configuration
file, you must move the contents of the existing MySQL data
directory before restarting the MySQL server.

See *Note windows-create-option-file::.

* If you reinstall or upgrade MySQL without first stopping and
removing the existing MySQL service and install MySQL using the
MySQL Configuration Wizard, you may see this error:

Error: Cannot create Windows service for MySql. Error: 0

This occurs when the Configuration Wizard tries to install the
service and finds an existing service with the same name.

One solution to this problem is to choose a service name other
than `mysql' when using the configuration wizard. This enables the
new service to be installed correctly, but leaves the outdated
service in place. Although this is harmless, it is best to remove
old services that are no longer in use.

To permanently remove the old `mysql' service, execute the
following command as a user with administrative privileges, on the
command-line:

shell> sc delete mysql
[SC] DeleteService SUCCESS

If the `sc' utility is not available for your version of Windows,
download the `delsrv' utility from
`http://www.microsoft.com/windows2000/techinfo/reskit/tools/existing/delsrv-o.asp'
and use the `delsrv mysql' syntax.

File: manual.info, Node: windows-upgrading, Next: windows-postinstallation, Prev: windows-troubleshooting, Up: windows-installation

3.10.6 Upgrading MySQL on Windows
---------------------------------

This section lists some of the steps you should take when upgrading
MySQL on Windows.

1. Review *Note upgrading::, for additional information on upgrading
MySQL that is not specific to Windows.

2. You should always back up your current MySQL installation before
performing an upgrade. See *Note backup-methods::.

3. Download the latest Windows distribution of MySQL from
`http://dev.mysql.com/downloads/'.

4. Before upgrading MySQL, you must stop the server. If the server is
installed as a service, stop the service with the following
command from the command prompt:

shell> NET STOP MySQL

If you are not running the MySQL server as a service, use *Note
`mysqladmin': mysqladmin. to stop it. For example, before
upgrading from MySQL 4.1 to 5.0, use *Note `mysqladmin':
mysqladmin. from MySQL 4.1 as follows:

shell> "C:\Program Files\MySQL\MySQL Server 4.1\bin\mysqladmin" -u root shutdown

*Note*:

If the MySQL `root' user account has a password, you need to
invoke *Note `mysqladmin': mysqladmin. with the `-p' option and
supply the password when prompted.

5. Before upgrading to MySQL 5.0 from a version previous to 4.1.5, or
from a version of MySQL installed from a Zip archive to a version
of MySQL installed with the MySQL Installation Wizard, you must
first manually remove the previous installation and MySQL service
(if the server is installed as a service).

To remove the MySQL service, use the following command:

shell> C:\mysql\bin\mysqld --remove

*If you do not remove the existing service, the MySQL Installation
Wizard may fail to properly install the new MySQL service.*

6. If you are using the MySQL Installation Wizard, start the wizard
as described in *Note windows-install-wizard::.

7. If you are installing MySQL from a Zip archive, extract the
archive. You may either overwrite your existing MySQL installation
(usually located at `C:\mysql'), or install it into a different
directory, such as `C:\mysql5'. Overwriting the existing
installation is recommended.

8. If you were running MySQL as a Windows service and you had to
remove the service earlier in this procedure, reinstall the
service. (See *Note windows-start-service::.)

9. Restart the server. For example, use `NET START MySQL' if you run
MySQL as a service, or invoke *Note `mysqld': mysqld. directly
otherwise.

10. If you encounter errors, see *Note windows-troubleshooting::.

File: manual.info, Node: windows-postinstallation, Next: windows-source-build, Prev: windows-upgrading, Up: windows-installation

3.10.7 Windows Postinstallation Procedures
------------------------------------------

On Windows, you need not create the data directory and the grant
tables. MySQL Windows distributions include the grant tables with a set
of preinitialized accounts in the `mysql' database under the data
directory. Regarding passwords, if you installed MySQL using the
Windows Installation Wizard, you may have already assigned passwords to
the accounts. (See *Note windows-install-wizard::.) Otherwise, use the
password-assignment procedure given in *Note default-privileges::.

Before setting up passwords, you might want to try running some client
programs to make sure that you can connect to the server and that it is
operating properly. Make sure that the server is running (see *Note
windows-server-first-start::), and then issue the following commands to
verify that you can retrieve information from the server. You may need
to specify directory different from `C:\mysql\bin' on the command line.
If you used the Windows Installation Wizard, the default directory is
`C:\Program Files\MySQL\MySQL Server 5.0', and the *Note `mysql':
mysql. and *Note `mysqlshow': mysqlshow. client programs are in
`C:\Program Files\MySQL\MySQL Server 5.0\bin'. See *Note
windows-install-wizard::, for more information.

Use *Note `mysqlshow': mysqlshow. to see what databases exist:

The list of installed databases may vary, but will always include the
minimum of `mysql' and `information_schema'. In most cases, the `test'
database will also be installed automatically.

The preceding command (and commands for other MySQL programs such as
*Note `mysql': mysql.) may not work if the correct MySQL account does
not exist. For example, the program may fail with an error, or you may
not be able to view all databases. If you installed using the MSI
packages and used the MySQL Server Instance Config Wizard, then the
`root' user will have been created automatically with the password you
supplied. In this case, you should use the `-u root' and `-p' options.
(You will also need to use the `-u root' and `-p' options if you have
already secured the initial MySQL accounts.) With `-p', you will be
prompted for the `root' password. For example:

If you specify a database name, *Note `mysqlshow': mysqlshow. displays
a list of the tables within the database:

Use the *Note `mysql': mysql. program to select information from a
table in the `mysql' database:

C:\> C:\mysql\bin\mysql -e "SELECT Host,Db,User FROM mysql.db"
+------+--------+------+
| host | db | user |
+------+--------+------+
| % | test | |
| % | test_% | |
+------+--------+------+

For more information about *Note `mysqlshow': mysqlshow. and *Note
`mysql': mysql, see *Note mysqlshow::, and *Note mysql::.

If you are running a version of Windows that supports services, you can
set up the MySQL server to run automatically when Windows starts. See
*Note windows-start-service::.

File: manual.info, Node: windows-source-build, Prev: windows-postinstallation, Up: windows-installation

3.10.8 Installing MySQL from Source on Windows
----------------------------------------------

* Menu:

* windows-source-build-cmake:: Building MySQL from the Standard Source Distribution
* windows-vc-plus-plus-build:: Building MySQL from a Windows Source Distribution
* windows-source-install:: Installing MySQL from a Source Build on Windows
* windows-source-testbuild:: Testing a Windows Source Build
* windows-sourcetree-build:: Creating a Windows Source Package from the Bazaar Repository

These instructions describe how to build binaries from source for MySQL
5.0 on Windows. Instructions are provided for building binaries from a
standard source distribution or from the Bazaar tree that contains the
latest development source.

*Note*:

The instructions here are strictly for users who want to test MySQL on
Microsoft Windows from the latest source distribution or from the
Bazaar tree. For production use, we do not advise using a MySQL server
built by yourself from source. Normally, it is best to use precompiled
binary distributions of MySQL that are built specifically for optimal
performance on Windows by Oracle Corporation. Instructions for
installing binary distributions are available in *Note
windows-installation::.

To build MySQL on Windows from source, you must satisfy the following
system, compiler, and resource requirements:

* Windows 2000, Windows XP, or newer version.

Windows Vista is supported when using Visual Studio 2005 provided
you have installed the following updates:

* Microsoft Visual Studio 2005 Professional Edition - ENU
Service Pack 1 (KB926601)
(http://support.microsoft.com/?kbid=926601)

* Security Update for Microsoft Visual Studio 2005 Professional
Edition - ENU (KB937061)
(http://support.microsoft.com/?kbid=937061)

* Update for Microsoft Visual Studio 2005 Professional Edition
- ENU (KB932232) (http://support.microsoft.com/?kbid=932232)

* To build from the standard source distribution, you will need
`CMake', which can be downloaded from `http://www.cmake.org'.
After installing, modify your `PATH' environment variable to
include the directory where `cmake' is located.

* Microsoft Visual C++ 2005 Express Edition, Visual Studio .Net 2003
(7.1), or Visual Studio 2005 (8.0) compiler system.

* If you are using Visual C++ 2005 Express Edition, you must also
install an appropriate Platform SDK. More information and links to
downloads for various Windows platforms is available from
`http://www.microsoft.com/downloads/details.aspx?familyid=0baf2b35-c656-4969-ace8-e4c0c0716adb'.

* If you are compiling from a Bazaar tree or making changes to the
parser, you need `bison' for Windows, which can be downloaded from
`http://gnuwin32.sourceforge.net/packages/bison.htm'. Download
the package labeled `Complete package, excluding sources'. After
installing the package, modify your `PATH' environment variable to
include the directory where `bison' is located.

* Cygwin might be necessary if you want to run the test script or
package the compiled binaries and support files into a Zip
archive. (Cygwin is needed only to test or package the
distribution, not to build it.) Cygwin is available from
`http://cygwin.com'.

* 3GB to 5GB of disk space.

There are three solutions available for building from the source code
on Windows:

* Build from the standard MySQL source distribution. For this you
will need `CMake' and Visual C++ Express Edition or Visual Studio.
Using this method you can select the storage engines that are
included in your build. To use this method, see *Note
windows-source-build-cmake::.

* Build from the MySQL Windows source distribution. The Windows
source distribution includes ready-made Visual Studio solution
files that enable support for all storage engines (except *Note
`NDB': mysql-cluster.). To build using using method you only need
Visual C++ Express Edition or Visual Studio. To use this method,
see *Note windows-vc-plus-plus-build::.

* Build directly from the Bazaar source repository. For this you
will need `CMake', Visual C++ Express Edition or Visual Studio,
and `bison'. For this method you need to create the distribution
on a Unix system and then copy the generated files to your Windows
build environment. To use this method, see *Note
windows-sourcetree-build::.

If you find something not working as expected, or you have suggestions
about ways to improve the current build process on Windows, please send
a message to the `win32' mailing list. See *Note mailing-lists::.

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3.10.8.1 Building MySQL from the Standard Source Distribution
.............................................................

You can build MySQL on Windows by using a combination of `cmake' and
Microsoft Visual Studio .NET 2003 (7.1), Microsoft Visual Studio 2005
(8.0) or Microsoft Visual C++ 2005 Express Edition. You must have the
appropriate Microsoft Platform SDK installed.

*Note*:

To compile from the source code using `CMake' you must use the standard
source distribution (for example, `mysql-5.0.93.tar.gz'). You build
from the same distribution as used to build MySQL on Unix, Linux and
other platforms. Do _not_ use the Windows Source distributions as they
do not contain the necessary configuration script and other files.

Follow this procedure to build MySQL:

1. If you are installing from a packaged source distribution, create
a work directory (for example, `C:\workdir'), and unpack the source
distribution there using `WinZip' or another Windows tool that can
read `.zip' files. This directory is the work directory in the
following instructions.

2. If you are installing from a Bazaar tree, the root directory of
that tree is the work directory in the following instructions.

3. Using a command shell, navigate to the work directory and run the
following command:

C:\workdir>win\configure.js OPTIONS

If you have associated the `.js' file extension with an
application such as a text editor, then you may need to use the
following command to force `configure.js' to be executed as a
script:

C:\workdir>cscript win\configure.js OPTIONS

These options are available for `configure.js':

* `WITH_INNOBASE_STORAGE_ENGINE': Enable the `InnoDB' storage
engine.

* `WITH_PARTITION_STORAGE_ENGINE': Enable user-defined
partitioning.

* `WITH_ARCHIVE_STORAGE_ENGINE': Enable the `ARCHIVE' storage
engine.

* `WITH_BLACKHOLE_STORAGE_ENGINE': Enable the `BLACKHOLE'
storage engine.

* `WITH_EXAMPLE_STORAGE_ENGINE': Enable the `EXAMPLE' storage
engine.

* `WITH_FEDERATED_STORAGE_ENGINE': Enable the `FEDERATED'
storage engine.

* `MYSQL_SERVER_SUFFIX=SUFFIX': Server suffix, default none.

* `COMPILATION_COMMENT=COMMENT': Server comment, default
"Source distribution".

* `MYSQL_TCP_PORT=PORT': Server port, default 3306.

* `DISABLE_GRANT_OPTIONS': Disables the the `--bootstrap',
`--skip-grant-tables', and `--init-file' options for *Note
`mysqld': mysqld. This option is available as of MySQL 5.0.36.

For example (type the command on one line):

C:\workdir>win\configure.js WITH_INNOBASE_STORAGE_ENGINE »
WITH_PARTITION_STORAGE_ENGINE MYSQL_SERVER_SUFFIX=-pro

4. From the work directory, execute the `win\build-vs8.bat' or
`win\build-vs71.bat' file, depending on the version of Visual
Studio you have installed. The script invokes `CMake', which
generates the `mysql.sln' solution file you will need to build
MySQL using Visual Studio..

You can also use `win\build-vs8_x64.bat' to build the 64-bit
version of MySQL. However, you cannot build the 64-bit version
with Visual Studio Express Edition. You must use Visual Studio
2005 (8.0) or higher.

5. From the work directory, open the generated `mysql.sln' file with
Visual Studio and select the proper configuration using the
`Configuration' menu. The menu provides `Debug', `Release',
`RelwithDebInfo', `MinRelInfo' options. Then select `Solution' >
`Build' to build the solution.

The build process will take some time. Please be patient.

Remember the configuration that you use in this step. It is
important later when you run the test script because that script
needs to know which configuration you used.

6. You should test you build before installation. See *Note
windows-source-testbuild::.

7. To install, use the instructions in *Note windows-source-install::.

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3.10.8.2 Building MySQL from a Windows Source Distribution
..........................................................

The Windows source distribution includes the necessary solution file
and the `vcproj' files required to build each component. Using this
method you are not able to select the storage engines that are included
in your build.

*Note*:

VC++ workspace files for MySQL 4.1 and above are compatible with
Microsoft Visual Studio 7.1 and tested by us before each release.

Follow this procedure to build MySQL:

1. Create a work directory (for example, `C:\workdir').

2. Unpack the source distribution in the aforementioned directory
using `WinZip' or another Windows tool that can read `.zip' files.

3. Start Visual Studio .Net 2003 (7.1).

4. From the `File' menu, select `Open Solution...'.

5. Open the `mysql.sln' solution you find in the work directory.

6. From the `Build' menu, select `Configuration Manager...'.

7. In the `Active Solution Configuration' pop-up menu, select the
configuration to use. You likely want to use one of `nt' (normal
server), `Max nt' (more engines and features), or `Debug'
configuration.

8. From the `Build' menu, select `Build Solution'.

9. Debug versions of the programs and libraries are placed in the
`client_debug' and `lib_debug' directories. Release versions of
the programs and libraries are placed in the `client_release' and
`lib_release' directories.

10. You should test you build before installation. See *Note
windows-source-testbuild::.

11. To install, use the instructions in *Note windows-source-install::.

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3.10.8.3 Installing MySQL from a Source Build on Windows
........................................................

When you are satisfied that the program you have built is working
correctly, stop the server. Now you can install the distribution. There
are two ways to do this, either by using the supplied installation
script or by copying the files individually by hand.

To use the script method you must have Cygwin installed as the script
is a Shell script. To execute the installation process, run the *Note
`make_win_bin_dist': make-win-bin-dist. script in the `scripts'
directory of the MySQL source distribution (see *Note
make-win-bin-dist::). This is a shell script, so you must have Cygwin
installed if you want to use it. It creates a Zip archive of the built
executables and support files that you can unpack to your desired
installation location.

It is also possible to install MySQL by copying directories and files
manually:

1. Create the directories where you want to install MySQL. For
example, to install into `C:\mysql', use these commands:

shell> mkdir C:\mysql
shell> mkdir C:\mysql\bin
shell> mkdir C:\mysql\data
shell> mkdir C:\mysql\share
shell> mkdir C:\mysql\scripts

If you want to compile other clients and link them to MySQL, you
should also create several additional directories:

shell> mkdir C:\mysql\include
shell> mkdir C:\mysql\lib
shell> mkdir C:\mysql\lib\debug
shell> mkdir C:\mysql\lib\opt

If you want to benchmark MySQL, create this directory:

shell> mkdir C:\mysql\sql-bench

Benchmarking requires Perl support. See *Note perl-support::.

2. From the work directory, copy into the `C:\mysql' directory the
following directories:

shell> cd \workdir
C:\workdir> copy client_release\*.exe C:\mysql\bin
C:\workdir> copy client_debug\mysqld.exe C:\mysql\bin\mysqld-debug.exe
C:\workdir> xcopy scripts\*.* C:\mysql\scripts /E
C:\workdir> xcopy share\*.* C:\mysql\share /E

If you want to compile other clients and link them to MySQL, you
should also copy several libraries and header files:

C:\workdir> copy lib_debug\mysqlclient.lib C:\mysql\lib\debug
C:\workdir> copy lib_debug\libmysql.* C:\mysql\lib\debug
C:\workdir> copy lib_debug\zlib.* C:\mysql\lib\debug
C:\workdir> copy lib_release\mysqlclient.lib C:\mysql\lib\opt
C:\workdir> copy lib_release\libmysql.* C:\mysql\lib\opt
C:\workdir> copy lib_release\zlib.* C:\mysql\lib\opt
C:\workdir> copy include\*.h C:\mysql\include
C:\workdir> copy libmysql\libmysql.def C:\mysql\include

If you want to benchmark MySQL, you should also do this:

C:\workdir> xcopy sql-bench\*.* C:\mysql\bench /E

After installation, set up and start the server in the same way as for
binary Windows distributions. See *Note windows-installation::.

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3.10.8.4 Testing a Windows Source Build
.......................................

You should test the server that you have built from source before using
the distribution.

To test the server you need to run the built *Note `mysqld': mysqld. By
default, using the source build examples, the MySQL base directory and
data directory are `C:\mysql' and `C:\mysql\data'. If you want to test
your server using the source tree root directory and its data directory
as the base directory and data directory, you need to tell the server
their path names. You can either do this on the command line with the
`--basedir' and `--datadir' options, or by placing appropriate options
in an option file. (See *Note option-files::.) If you have an existing
data directory elsewhere that you want to use, you can specify its path
name instead.

When the server is running in standalone fashion or as a service based
on your configuration, try to connect to it from the *Note `mysql':
mysql. interactive command-line utility.

You can also run the standard test script, `mysql-test-run.pl'. This
script is written in Perl, so you'll need either Cygwin or ActiveState
Perl to run it. You may also need to install the modules required by the
script. To run the test script, change location into the `mysql-test'
directory under the work directory, set the `MTR_VS_CONFIG' environment
variable to the configuration you selected earlier (or use the
`--vs-config' option), and invoke `mysql-test-run.pl'. For example
(using Cygwin and the `bash' shell):

shell> `cd mysql-test'
shell> `export MTR_VS_CONFIG=debug'
shell> `./mysql-test-run.pl --force --timer'
shell> `./mysql-test-run.pl --force --timer --ps-protocol'

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3.10.8.5 Creating a Windows Source Package from the Bazaar Repository
.....................................................................

To create a Windows source package from the current Bazaar source tree,
use the instructions here. This procedure must be performed on a system
running a Unix or Unix-like operating system because some of the
configuration and build steps require tools that work only on Unix. For
example, the following procedure is known to work well on Linux.

1. Copy the Bazaar source tree for MySQL 5.0. For instructions on how
to do this, see *Note installing-development-tree::.

2. Configure and build the distribution so that you have a server
binary to work with. One way to do this is to run the following
command in the top-level directory of your source tree:

shell> ./BUILD/compile-pentium-max

3. After making sure that the build process completed successfully,
run the following utility script from top-level directory of your
source tree:

shell> ./scripts/make_win_src_distribution

This script creates a Windows source package to be used on your
Windows system. You can supply different options to the script
based on your needs. See *Note make-win-src-distribution::, for a
list of permissible options.

By default, *Note `make_win_src_distribution':
make-win-src-distribution. creates a Zip-format archive with the
name `mysql-VERSION-win-src.zip', where VERSION represents the
version of your MySQL source tree.

4. Copy or upload the Windows source package that you have just
created to your Windows machine. To compile it, use the
instructions in *Note windows-vc-plus-plus-build::.

File: manual.info, Node: macosx-installation, Next: linux-installation-rpm, Prev: windows-installation, Up: installing

3.11 Installing MySQL on Mac OS X
=================================

You can install MySQL on Mac OS X 10.3.x (`Panther') or newer using a
Mac OS X binary package in PKG format instead of the binary tarball
distribution. Please note that older versions of Mac OS X (for example,
10.1.x or 10.2.x) are *not* supported by this package.

The package is located inside a disk image (`.dmg') file that you first
need to mount by double-clicking its icon in the Finder. It should then
mount the image and display its contents.

When installing from the package version, you should also install the
MySQL Preference Pane, which will enable you to control the startup and
execution of your MySQL server from System Preferences.

To obtain MySQL, see *Note getting-mysql::.

*Note*:

Before proceeding with the installation, be sure to shut down all
running MySQL server instances by using either the MySQL Manager
Application (on Mac OS X Server) or *Note `mysqladmin shutdown':
mysqladmin. on the command line.

To actually install the MySQL PKG file, double-click the package icon.
This launches the Mac OS X Package Installer, which guides you through
the installation of MySQL.

Due to a bug in the Mac OS X package installer, you may see this error
message in the destination disk selection dialog:

You cannot install this software on this disk. (null)

If this error occurs, simply click the `Go Back' button once to return
to the previous screen. Then click `Continue' to advance to the
destination disk selection again, and you should be able to choose the
destination disk correctly. We have reported this bug to Apple and it is
investigating this problem.

The Mac OS X PKG of MySQL installs itself into
`/usr/local/mysql-VERSION' and also installs a symbolic link,
`/usr/local/mysql', that points to the new location. If a directory
named `/usr/local/mysql' exists, it is renamed to
`/usr/local/mysql.bak' first. Additionally, the installer creates the
grant tables in the `mysql' database by executing *Note
`mysql_install_db': mysql-install-db.

The installation layout is similar to that of a `tar' file binary
distribution; all MySQL binaries are located in the directory
`/usr/local/mysql/bin'. The MySQL socket file is created as
`/tmp/mysql.sock' by default. See *Note installation-layouts::.

MySQL installation requires a Mac OS X user account named `mysql'. A
user account with this name should exist by default on Mac OS X 10.2
and up.

If you are running Mac OS X Server, a version of MySQL should already
be installed. The following table shows the versions of MySQL that ship
with Mac OS X Server versions.

Mac OS X Server MySQL Version
Version
10.2-10.2.2 3.23.51
10.2.3-10.2.6 3.23.53
10.3 4.0.14
10.3.2 4.0.16
10.4.0 4.1.10a

This manual section covers the installation of the official MySQL Mac
OS X PKG only. Make sure to read Apple's help information about
installing MySQL: Run the `Help View' application, select `Mac OS X
Server' help, do a search for `MySQL,' and read the item entitled
`Installing MySQL.'

For preinstalled versions of MySQL on Mac OS X Server, note especially
that you should start *Note `mysqld': mysqld. with `safe_mysqld'
instead of *Note `mysqld_safe': mysqld-safe. if MySQL is older than
version 4.0.

If you previously used Marc Liyanage's MySQL packages for Mac OS X from
`http://www.entropy.ch', you can simply follow the update instructions
for packages using the binary installation layout as given on his pages.

If you are upgrading from Marc's 3.23.x versions or from the Mac OS X
Server version of MySQL to the official MySQL PKG, you also need to
convert the existing MySQL privilege tables to the current format,
because some new security privileges have been added. See *Note
mysql-upgrade::.

If you want MySQL to start automatically during system startup, you
also need to install the MySQL Startup Item. It is part of the Mac OS X
installation disk images as a separate installation package. Simply
double-click the `MySQLStartupItem.pkg' icon and follow the
instructions to install it. The Startup Item need be installed only
once. There is no need to install it each time you upgrade the MySQL
package later.

The Startup Item for MySQL is installed into
`/Library/StartupItems/MySQLCOM'. (Before MySQL 4.1.2, the location was
`/Library/StartupItems/MySQL', but that collided with the MySQL Startup
Item installed by Mac OS X Server.) Startup Item installation adds a
variable `MYSQLCOM=-YES-' to the system configuration file
`/etc/hostconfig'. If you want to disable the automatic startup of
MySQL, simply change this variable to `MYSQLCOM=-NO-'.

On Mac OS X Server, the default MySQL installation uses the variable
`MYSQL' in the `/etc/hostconfig' file. The MySQL Startup Item installer
disables this variable by setting it to `MYSQL=-NO-'. This avoids boot
time conflicts with the `MYSQLCOM' variable used by the MySQL Startup
Item. However, it does not shut down a running MySQL server. You should
do that yourself.

After the installation, you can start up MySQL by running the following
commands in a terminal window. You must have administrator privileges
to perform this task.

If you have installed the Startup Item, use this command:

shell> sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
(ENTER YOUR PASSWORD, IF NECESSARY)
(PRESS CONTROL-D OR ENTER "EXIT" TO EXIT THE SHELL)

If you do not use the Startup Item, enter the following command
sequence:

shell> cd /usr/local/mysql
shell> sudo ./bin/mysqld_safe
(ENTER YOUR PASSWORD, IF NECESSARY)
(PRESS CONTROL-Z)
shell> bg
(PRESS CONTROL-D OR ENTER "EXIT" TO EXIT THE SHELL)

You should be able to connect to the MySQL server, for example, by
running `/usr/local/mysql/bin/mysql'.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

You might want to add aliases to your shell's resource file to make it
easier to access commonly used programs such as *Note `mysql': mysql.
and *Note `mysqladmin': mysqladmin. from the command line. The syntax
for `bash' is:

alias mysql=/usr/local/mysql/bin/mysql
alias mysqladmin=/usr/local/mysql/bin/mysqladmin

For `tcsh', use:

alias mysql /usr/local/mysql/bin/mysql
alias mysqladmin /usr/local/mysql/bin/mysqladmin

Even better, add `/usr/local/mysql/bin' to your `PATH' environment
variable. You can do this by modifying the appropriate startup file for
your shell. For more information, see *Note invoking-programs::.

If you are upgrading an existing installation, note that installing a
new MySQL PKG does not remove the directory of an older installation.
Unfortunately, the Mac OS X Installer does not yet offer the
functionality required to properly upgrade previously installed
packages.

To use your existing databases with the new installation, you'll need
to copy the contents of the old data directory to the new data
directory. Make sure that neither the old server nor the new one is
running when you do this. After you have copied over the MySQL database
files from the previous installation and have successfully started the
new server, you should consider removing the old installation files to
save disk space. Additionally, you should also remove older versions of
the Package Receipt directories located in
`/Library/Receipts/mysql-VERSION.pkg'.

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3.12 Installing MySQL from RPM Packages on Linux
================================================

The recommended way to install MySQL on RPM-based Linux distributions
is by using the RPM packages. The RPMs that we provide to the community
should work on all versions of Linux that support RPM packages and use
`glibc' 2.3. We also provide RPMs with binaries that are statically
linked to a patched version of `glibc' 2.2, but only for the x86
(32-bit) architecture. To obtain RPM packages, see *Note
getting-mysql::.

For non-RPM Linux distributions, you can install MySQL using a
`.tar.gz' package. See *Note binary-installation::.

We do provide some platform-specific RPMs; the difference between a
platform-specific RPM and a generic RPM is that a platform-specific RPM
is built on the targeted platform and is linked dynamically whereas a
generic RPM is linked statically with LinuxThreads.

*Note*:

RPM distributions of MySQL often are provided by other vendors. Be
aware that they may differ in features and capabilities from those
built by us, and that the instructions in this manual do not
necessarily apply to installing them. The vendor's instructions should
be consulted instead.

If you have problems with an RPM file (for example, if you receive the
error `Sorry, the host 'XXXX' could not be looked up'), see *Note
binary-notes-linux::.

In most cases, you need to install only the `MySQL-server' and
`MySQL-client' packages to get a functional MySQL installation. The
other packages are not required for a standard installation.

For upgrades, if your installation was originally produced by
installing multiple RPM packages, it is best to upgrade all the
packages, not just some. For example, if you previously installed the
server and client RPMs, do not upgrade just the server RPM.

If you get a dependency failure when trying to install MySQL packages
(for example, `error: removing these packages would break dependencies:
libmysqlclient.so.10 is needed by ...'), you should also install the
`MySQL-shared-compat' package, which includes both the shared libraries
for backward compatibility (`libmysqlclient.so.12' for MySQL 4.0 and
`libmysqlclient.so.10' for MySQL 3.23).

Some Linux distributions still ship with MySQL 3.23 and they usually
link applications dynamically to save disk space. If these shared
libraries are in a separate package (for example, `MySQL-shared'), it
is sufficient to simply leave this package installed and just upgrade
the MySQL server and client packages (which are statically linked and
do not depend on the shared libraries). For distributions that include
the shared libraries in the same package as the MySQL server (for
example, Red Hat Linux), you could either install our 3.23
`MySQL-shared' RPM, or use the `MySQL-shared-compat' package instead.
(Do not install both.)

The RPM packages shown in the following list are available. The names
shown here use a suffix of `.glibc23.i386.rpm', but particular packages
can have different suffixes, as described later. Packages that have
`community' in the names are Community Server builds, available from
MySQL 5.0.27 on.

* `MySQL-server-VERSION.glibc23.i386.rpm',
`MySQL-server-community-VERSION.glibc23.i386.rpm'

The MySQL server. You need this unless you only want to connect to
a MySQL server running on another machine.

* `MySQL-client-VERSION.glibc23.i386.rpm',
`MySQL-client-community-VERSION.glibc23.i386.rpm'

The standard MySQL client programs. You probably always want to
install this package.

* `MySQL-bench-VERSION.glibc23.i386.rpm'

Tests and benchmarks. Requires Perl and the `DBI' and `DBD::mysql'
modules.

* `MySQL-devel-VERSION.glibc23.i386.rpm',
`MySQL-devel-community-VERSION.glibc23.i386.rpm'

The libraries and include files that are needed if you want to
compile other MySQL clients, such as the Perl modules.

* `MySQL-debuginfo-VERSION.glibc23.i386.rpm',
`MySQL-community-debuginfo-VERSION.glibc23.i386.rpm'

This package contains debugging information. `debuginfo' RPMs are
never needed to use MySQL software; this is true both for the
server and for client programs. However, they contain additional
information that might be needed by a debugger to analyze a crash.

* `MySQL-shared-VERSION.glibc23.i386.rpm',
`MySQL-shared-community-VERSION.glibc23.i386.rpm'

This package contains the shared libraries (`libmysqlclient.so*')
that certain languages and applications need to dynamically load
and use MySQL. It contains single-threaded and thread-safe
libraries. If you install this package, do not install the
`MySQL-shared-compat' package.

* `MySQL-shared-compat-VERSION.glibc23.i386.rpm'

This package includes the shared libraries for MySQL 3.23, 4.0,
and so on, up to the current release. It contains single-threaded
and thread-safe libraries. Install this package instead of
`MySQL-shared' if you have applications installed that are
dynamically linked against older versions of MySQL but you want to
upgrade to the current version without breaking the library
dependencies.

* `MySQL-clustermanagement-communityVERSION.glibc23.i386.rpm',
`MySQL-clusterstorage-communityVERSION.glibc23.i386.rpm',
`MySQL-clustertools-communityVERSION.glibc23.i386.rpm',
`MySQL-clusterextra-communityVERSION.glibc23.i386.rpm'

Packages that contain additional files for MySQL Cluster
installations. These are platform-specific RPMs, in contrast to
the platform-independent `ndb-XXX' RPMs.

*Note*:

The `MySQL-clustertools' RPM requires a working installation of
perl and the `DBI' and `HTML::Template' packages. See *Note
perl-support::, and *Note mysql-cluster-programs-ndb-size-pl::, for
more information.

* `MySQL-ndb-management-VERSION.glibc23.i386.rpm',
`MySQL-ndb-storage-VERSION.glibc23.i386.rpm',
`MySQL-ndb-tools-VERSION.glibc23.i386.rpm',
`MySQL-ndb-extra-VERSION.glibc23.i386.rpm'

Packages that contain additional files for MySQL Cluster
installations. These are platform-independent RPMs, in contrast to
the platform-specific `clusterXXX-community' RPMs.

* `MySQL-test-community-VERSION.glibc23.i386.rpm'

This package includes the MySQL test suite.

* `MySQL-VERSION.src.rpm'

This contains the source code for all of the previous packages. It
can also be used to rebuild the RPMs on other architectures (for
example, Alpha or SPARC).

The suffix of RPM package names (following the VERSION value) has the
following syntax:

[.PLATFORM].CPU.rpm

The PLATFORM and CPU values indicate the type of system for which the
package is built. PLATFORM, if present, indicates the platform, and
CPU indicates the processor type or family.

If the PLATFORM value is missing (for example,
`MySQL-server-VERSION.i386.rpm'), the package is statically linked
against a version of `glibc' 2.2 that has been patched to handle larger
numbers of threads with larger stack sizes than the stock library.

If PLATFORM is present, the package is dynamically linked against
`glibc' 2.3 and the PLATFORM value indicates whether the package is
platform independent or intended for a specific platform, as shown in
the following table.

PLATFORM Value Intended Use
`glibc23' Platform independent, should run on any Linux
distribution that supports `glibc' 2.3
`rhel3', `rhel4' Red Hat Enterprise Linux 3 or 4
`sles9', `sles10' SuSE Linux Enterprise Server 9 or 10

The CPU value indicates the processor type or family for which the
package is built.

CPU Value Intended Processor Type or Family
`i386' x86 processor, 386 and up
`i586' x86 processor, Pentium and up
`x86_64' 64-bit x86 processor
`ia64' Itanium (IA-64) processor

To see all files in an RPM package (for example, a `MySQL-server' RPM),
run a command like this:

shell> rpm -qpl MySQL-server-VERSION.glibc23.i386.rpm

To perform a standard minimal installation, install the server and
client RPMs:

shell> rpm -i MySQL-server-VERSION.glibc23.i386.rpm
shell> rpm -i MySQL-client-VERSION.glibc23.i386.rpm

To install only the client programs, install just the client RPM:

shell> rpm -i MySQL-client-VERSION.glibc23.i386.rpm

RPM provides a feature to verify the integrity and authenticity of
packages before installing them. If you would like to learn more about
this feature, see *Note verifying-package-integrity::.

The server RPM places data under the `/var/lib/mysql' directory. The
RPM also creates a login account for a user named `mysql' (if one does
not exist) to use for running the MySQL server, and creates the
appropriate entries in `/etc/init.d/' to start the server automatically
at boot time. (This means that if you have performed a previous
installation and have made changes to its startup script, you may want
to make a copy of the script so that you do not lose it when you
install a newer RPM.) See *Note automatic-start::, for more information
on how MySQL can be started automatically on system startup.

If you want to install the MySQL RPM on older Linux distributions that
do not support initialization scripts in `/etc/init.d' (directly or
through a symlink), you should create a symbolic link that points to
the location where your initialization scripts actually are installed.
For example, if that location is `/etc/rc.d/init.d', use these commands
before installing the RPM to create `/etc/init.d' as a symbolic link
that points there:

shell> cd /etc
shell> ln -s rc.d/init.d .

However, all current major Linux distributions should support the new
directory layout that uses `/etc/init.d', because it is required for
LSB (Linux Standard Base) compliance.

If the RPM files that you install include `MySQL-server', the *Note
`mysqld': mysqld. server should be up and running after installation.
You should be able to start using MySQL.

If something goes wrong, you can find more information in the binary
installation section. See *Note binary-installation::.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

During RPM installation, a user named `mysql' and a group named `mysql'
are created on the system. This is done using the `useradd',
`groupadd', and `usermod' commands. Those commands require appropriate
administrative privileges, which is ensured for locally managed users
and groups (as listed in the `/etc/passwd' and `/etc/group' files) by
the RPM installation process being run by `root'.

If you log in as the `mysql' user, you may find that MySQL displays
`Invalid (old?) table or database name' errors that mention `.mysqlgui',
`lost+found', `.mysqlgui', `.bash_history', `.fonts.cache-1',
`.lesshst', `.mysql_history', `.profile', `.viminfo', and similar files
created by MySQL or operating system utilities. You can safely ignore
these error messages or remove the files or directories that cause them
if you do not need them.

For nonlocal user management (LDAP, NIS, and so forth), the
administrative tools may require additional authentication (such as a
password), and will fail if the installing user does not provide this
authentication. Even if they fail, the RPM installation will not abort
but succeed, and this is intentional. If they failed, some of the
intended transfer of ownership may be missing, and it is recommended
that the system administrator then manually ensures some appropriate
user andgroup exists and manually transfers ownership following the
actions in the RPM spec file.

File: manual.info, Node: solaris-installation, Next: i5os-installation, Prev: linux-installation-rpm, Up: installing

3.13 Installing MySQL on Solaris
================================

To obtain a binary MySQL distribution for Solaris in tarball or PKG
format, `http://dev.mysql.com/downloads/mysql/5.0.html'.

If you install MySQL using a binary tarball distribution on Solaris,
you may run into trouble even before you get the MySQL distribution
unpacked, as the Solaris `tar' cannot handle long file names. This
means that you may see errors when you try to unpack MySQL.

If this occurs, you must use GNU `tar' (`gtar') to unpack the
distribution.

You can install MySQL on Solaris using a binary package in PKG format
instead of the binary tarball distribution. Before installing using the
binary PKG format, you should create the `mysql' user and group, for
example:

groupadd mysql
useradd -g mysql mysql

Some basic PKG-handling commands follow:

* To add a package:

pkgadd -d PACKAGE_NAME.pkg

* To remove a package:

pkgrm PACKAGE_NAME

* To get a full list of installed packages:

pkginfo

* To get detailed information for a package:

pkginfo -l PACKAGE_NAME

* To list the files belonging to a package:

pkgchk -v PACKAGE_NAME

* To get packaging information for an arbitrary file:

pkgchk -l -p FILE_NAME

For additional information about installing MySQL on Solaris, see *Note
solaris::.

File: manual.info, Node: i5os-installation, Next: netware-installation, Prev: solaris-installation, Up: installing

3.14 Installing MySQL on i5/OS
==============================

The i5/OS POWER MySQL package was created in cooperation with IBM.
MySQL works within the Portable Application Solution Environment (PASE)
on the System i series of hardware and will also provide database
services for the Zend Core for i5/OS.

MySQL for i5/OS is provided both as a `tar' file and as a save file
(`.savf') package that can be downloaded and installed directly without
any additional installation steps required. To install MySQL using the
`tar' file, see *Note binary-installation::.

MySQL is only supported on i5/OS V5R4 or later releases. The i5/OS PASE
must be installed for MySQL to operate. You must be able to login as a
user in `*SECOFR' class.

You should the installation notes and tips for i5/OS before starting
installation. See i5/OS Installation Notes.

*Before Installation:*

*Note*:

The installation package will use an existing configuration if you have
previously installed MySQL (which is identified by looking for the file
`/etc/my.cnf'). The values for the data directory (`DATADIR') and owner
of the MySQL files (`USRPRF') specified during the installation will be
ignored, and the values determined from the `/etc/my.cnf' will be used
instead.

If you want to change these parameters during a new install, you should
temporarily rename `/etc/my.cnf', install MySQL using the new
parameters you want to use, and then merge your previous `/etc/my.cnf'
configuration settings with the new `/etc/my.cnf' file that is created
during installation.

* You must have a user profile with PASE with suitable privileges.
The user should be within the `*SECOFR' class, such as the
`QSECOFR' user ID. You can use the `WRKUSRPRF' command to check
your user profile.

* For network connections to MySQL, you must have TCP/IP enabled.
You should also check the following:

* Ensure that a name has defined for the system. Run the
Configure TCP/IP (`CFGTCP') command and select option 12
(Change TCP/IP domain information) to display this setting.
Make sure that a value is listed in the Host name field.

* Make sure that the system has a loopback entry which
represents the `localhost' or `127.0.0.1'.

* Ensure that the IP address of the IBM i machine is mapped
correctly to the host name.

To install MySQL on i5/OS, follow these steps:

1. On the System i machine, create a save file that will be used to
receive the downloaded installation save file. The file should be
located within the General Purpose Library (`QGPL'):

CRTSAVF FILE(QGPL/MYSQLINST) TESXT('MySQL Save file')

2. Download the MySQL installation save file in 32-bit
(`mysql-5.0.82-i5os-power-32bit.savf') or 64-bit
(`mysql-5.0.82-i5os-power-64bit.savf') from MySQL Downloads
(http://dev.mysql.com/downloads).

3. You need to FTP the downloaded `.savf' file directly into the
`QGPL/MYSQLINST' file on the System i server. You can do this
through FTP using the following steps after logging in to the
System i machine:

ftp> bin
ftp> cd qgpl
ftp> put mysql-5.0.82-i5os-power.savf mysqlinst

4. Log into the System i server using a user in the `*SECOFR' class,
such as the `QSECOFR' user ID.

5. You need to restore the installation library stored in the `.savf'
save file:

RSTLIB MYSQLINST DEV(*SAVF) SAVF(QGPL/MYSQLINST) MBROPT(*ALL) ALWOBJDIF(*ALL)

*Note*:

You can ignore the security changes-type message at the bottom of
the installation panel.

6. Once you have finished restoring the `MYSQLINST' library, check
that all the necessary objects for installation are on the system
by using the Display Library (`DSPLIB') command:

DSPLIB LIB(MYSQLINST)

7. You need to execute the installation command,
`MYSQLINST/INSMYSQL'. You can specify three parameter settings
during installation:

* `DIR('/QOPENSYS/USR/LOCAL/MYSQL')' sets the installation
location for the MySQL files. The directory will be created
if it does not already exist.

* `DATADIR('/QOPENSYS/USR/LOCAL/MYSQL/DATA')' sets the location
of the directory that will be used to store the database
files and binary logs. The default setting is
`/QOpenSys/usr/local/mysql/data'. Note that if the installer
detects an existing installation (due to the existence of
`/etc/my.cnf'), then the existing setting will be used
instead of the default.

* `USRPRF(MYSQL)' sets the user profile that will own the files
that are installed. The profile will be created if it does not
already exist.

*Note*:

You should choose an appropriate user for using the MySQL
server installation. The user will be used whenever you need
to do any administration on the MySQL server.

Once you have set the appropriate parameters, you can begin the
installation.

The installation copies all the necessary files into a directory
matching the `DIR' configuration value; sets the ownership on
those files, sets up the MySQL environment and creates the MySQL
configuration file (in `/etc/my.cnf') completing all the steps in
a typical binary installation process automatically. If this is a
new installation of MySQL, or if the installer detects that this
is a new version (because the `/etc/my.cnf' file does not exist),
then the initial core MySQL databases will also be created during
installation.

Once the installation has been completed, you will get a notice
advising you to set the password for the root user. For more
information, *Note postinstallation::.

8. Once the installation has completed, you can delete the
installation file:

DLTLIB LIB(MYSQLINST)

*Upgrading an existing MySQL instance*

You need to execute the upgrade command, `MYSQLINST/UPGMYSQL'.

*Note*:

You cannot use `MYSQLINST/UPGMYSQL' to upgrade between major versions
of MySQL (for example from 5.0 to 5.1). For information and advice on
migrating between major versions you can use the advice provided in
*Note upgrading-from-previous-series::.

You must specify 6 parameters to perform an upgrade:

* `DIR('/QOpenSys/usr/local/')': Sets the installation location for
the MySQL files. The directory will be created if it does not
already exist. This is the directory that the MySQL server will be
installed into, inside a directory with a name matching the
version and release. For example, if installing MySQL 5.0.82 with
the `DIR' set to `/QOpenSys/usr/local/' would result in
`/QOpenSys/usr/local/mysql-5.0.82-i5os-power64' and a symbolic
link to this directory will be created in
`/QOpenSys/usr/local/mysql'.

* `DATADIR('/QOpenSys/mysql/data')': Sets the location of the
directory that will be upgraded.

* `USRPRF('MYSQL')': Sets the user profile that will own the files
that are installed. The profile will be created if it does not
already exist; if it is created as part of the upgrade process, it
will be disabled initially. You may wish to enable this user
profile so that it can be used to start the MySQL server later. It
is best practice to use the one previously created during the
first installation.

* `MYSQLUSR('root user')': Any user account in the current MySQL
server with `SUPER' privileges.

* `PASSWORD('root user password')': The password for the above
account. This is necessary as the upgrade starts the MySQL server
to upgrade the tables and the password is need to be able to
shutdown the MySQL server.

* `CURINST('path to previous install')': The full path to the
installation that is being upgraded. For example an installation in
`/QOpenSys/usr/local/' will be
`/QOpenSys/usr/local/msyql-5.1.30-i5os-power64'. Failure to
specify this option may result in corruption of your existing data
files.

For example:

MYSQLINST/UPGMYSQL DIR('/QOPENSYS/USR/LOCAL/') DATADIR('/QOPENSYS/MYSQL/DATA') »
USERPRF(MYSQL) MYSQLUSR('ROOT') PASSWORD('ROOT') CURINST('/QOPENSYS/USR/LOCAL/MYSQL-5.1.30-I5OS-POWER64')

You should receive a Program Message indicating `UPGRADE SUCCESSFUL!'
upon completion or an error message if there is a problem.You can view
the upgrade programs progression and the error in the text file
`upgrade.log' in the installation directory.

*To start MySQL*:

1. Log into the System i server using the user profile create or
specified during installation. By default, this is `MYSQL'.

*Note*:

You should start *Note `mysqld_safe': mysqld-safe. using a user
that in the PASE environment has the id=0 (the equivalent of the
standard Unix `root' user). If you do not use a user with this ID
then the system will be unable to change the user when executing
*Note `mysqld': mysqld. as set using `--user' option. If this
happens, *Note `mysqld': mysqld. may be unable to read the files
located within the MySQL data directory and the execution will
fail.

2. Enter the PASE environment using `call qp2term'.

3. Start the MySQL server by changing to the installation directory
and running *Note `mysqld_safe': mysqld-safe, specifying the user
name used to install the server. The installer conveniently
installs a symbolic link to the installation directory
(`mysql-5.0.42-i5os-power-32bit') as `/opt/mysql/mysql':

> cd /opt/mysql/mysql
> bin/mysqld_safe --user=mysql &

You should see a message similar to the following:

Starting mysqld daemon with databases »
from /opt/mysql/mysql-enterprise-5.0.42-i5os-power-32bit/data

If you are having problems starting MySQL server, see *Note
starting-server::.

*To stop MySQL*:

1. Log into the System i server using the user profile create or
specified during installation. By default, this is `MYSQL'.

2. Enter the PASE environment using `call qp2term'.

3. Stop the MySQL server by changing into the installation directory
and running *Note `mysqladmin': mysqladmin, specifying the user
name used to install the server:

> cd /opt/mysql/mysql
> bin/mysqladmin -u root shutdown

If the session that you started and stopped MySQL are the same,
you may get the log output from `mysqld':

STOPPING server from pid file »
/opt/mysql/mysql-enterprise-5.0.42-i5os-power-32bit/data/I5DBX.RCHLAND.IBM.COM.pid
070718 10:34:20 mysqld ended

If the sessions used to start and stop MySQL are different, you
will not receive any confirmation of the shutdown.

_Note and tips_

* A problem has been identified with the installation process on
DBCS systems. If you are having problems install MySQL on a DBCS
system, you need to change your job's coded character set
identifier (`CSSID') to 37 (`EBCDIC') before executing the install
command, `INSMYSQL'. To do this, determine your existing `CSSID'
(using `DSPJOB' and selecting option 2), execute `CHGJOB
CSSID(37)', run `INSMYSQL' to install MySQL and then execute
`CHGJOB' again with your original `CSSID.'

* If you want to use the Perl scripts that are included with MySQL,
you need to download the iSeries Tools for Developers (5799-PTL).
See `http://www-03.ibm.com/servers/enable/site/porting/tools/'.

File: manual.info, Node: netware-installation, Next: binary-installation, Prev: i5os-installation, Up: installing

3.15 Installing MySQL on NetWare
================================

Porting MySQL to NetWare was an effort spearheaded by Novell. Novell
customers should be pleased to note that NetWare 6.5 ships with bundled
MySQL binaries, complete with an automatic commercial use license for
all servers running that version of NetWare.

MySQL for NetWare is compiled using a combination of Metrowerks
CodeWarrior for NetWare and special cross-compilation versions of the
GNU autotools.

The latest binary packages for NetWare can be obtained at
`http://dev.mysql.com/downloads/'. See *Note getting-mysql::.

To host MySQL, the NetWare server must meet these requirements:

* The latest Support Pack of NetWare 6.5
(http://support.novell.com/filefinder/18197/index.html) must be
installed.

* The system must meet Novell's minimum requirements to run the
respective version of NetWare.

* MySQL data and the program binaries must be installed on an NSS
volume; traditional volumes are not supported.

To install MySQL for NetWare, use the following procedure:

1. If you are upgrading from a prior installation, stop the MySQL
server. This is done from the server console, using the following
command:

SERVER: mysqladmin -u root shutdown

*Note*:

If the MySQL `root' user account has a password, you need to
invoke *Note `mysqladmin': mysqladmin. with the `-p' option and
supply the password when prompted.

2. Log on to the target server from a client machine with access to
the location where you are installing MySQL.

3. Extract the binary package Zip file onto the server. Be sure to
allow the paths in the Zip file to be used. It is safe to simply
extract the file to `SYS:\'.

If you are upgrading from a prior installation, you may need to
copy the data directory (for example, `SYS:MYSQL\DATA'), as well as
`my.cnf', if you have customized it. You can then delete the old
copy of MySQL.

4. You might want to rename the directory to something more
consistent and easy to use. The examples in this manual use
`SYS:MYSQL' to refer to the installation directory.

Note that MySQL installation on NetWare does not detect if a
version of MySQL is already installed outside the NetWare release.
Therefore, if you have installed the latest MySQL version from the
Web (for example, MySQL 4.1 or later) in `SYS:\MYSQL', you must
rename the folder before upgrading the NetWare server; otherwise,
files in `SYS:\MySQL' are overwritten by the MySQL version present
in NetWare Support Pack.

5. At the server console, add a search path for the directory
containing the MySQL NLMs. For example:

SERVER: SEARCH ADD SYS:MYSQL\BIN

6. Initialize the data directory and the grant tables, if necessary,
by executing *Note `mysql_install_db': mysql-install-db. at the
server console.

7. Start the MySQL server using *Note `mysqld_safe': mysqld-safe. at
the server console.

8. To finish the installation, you should also add the following
commands to `autoexec.ncf'. For example, if your MySQL
installation is in `SYS:MYSQL' and you want MySQL to start
automatically, you could add these lines:

#Starts the MySQL 5.0.x database server
SEARCH ADD SYS:MYSQL\BIN
MYSQLD_SAFE

If you are running MySQL on NetWare 6.0, we strongly suggest that
you use the `--skip-external-locking' option on the command line:

#Starts the MySQL 5.0.x database server
SEARCH ADD SYS:MYSQL\BIN
MYSQLD_SAFE --skip-external-locking

It is also necessary to use *Note `CHECK TABLE': check-table. and
*Note `REPAIR TABLE': repair-table. instead of *Note `myisamchk':
myisamchk, because *Note `myisamchk': myisamchk. makes use of
external locking. External locking is known to have problems on
NetWare 6.0; the problem has been eliminated in NetWare 6.5. Note
that the use of MySQL on Netware 6.0 is not officially supported.

*Note `mysqld_safe': mysqld-safe. on NetWare provides a screen
presence. When you unload (shut down) the *Note `mysqld_safe':
mysqld-safe. NLM, the screen does not go away by default. Instead,
it prompts for user input:

*<NLM has terminated; Press any key to close the screen>*

If you want NetWare to close the screen automatically instead, use
the `--autoclose' option to *Note `mysqld_safe': mysqld-safe. For
example:

#Starts the MySQL 5.0.x database server
SEARCH ADD SYS:MYSQL\BIN
MYSQLD_SAFE --autoclose

The behavior of *Note `mysqld_safe': mysqld-safe. on NetWare is
described further in *Note mysqld-safe::.

9. When installing MySQL, either for the first time or upgrading from
a previous version, download and install the latest and
appropriate Perl module and PHP extensions for NetWare:

* Perl:
`http://forge.novell.com/modules/xfcontent/downloads.php/perl/Modules/'

* PHP:
`http://forge.novell.com/modules/xfcontent/downloads.php/php/Modules/'

If there was an existing installation of MySQL on the NetWare server,
be sure to check for existing MySQL startup commands in `autoexec.ncf',
and edit or delete them as necessary.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

File: manual.info, Node: binary-installation, Next: source-installation, Prev: netware-installation, Up: installing

3.16 Installing MySQL from Generic Binaries on Other Unix-Like Systems
======================================================================

Oracle provides a set of binary distributions of MySQL. These include
binary distributions in the form of compressed `tar' files (files with a
`.tar.gz' extension) for a number of platforms, as well as binaries in
platform-specific package formats for selected platforms.

This section covers the installation of MySQL from a compressed `tar'
file binary distribution. For other platform-specific package formats,
see the other platform-specific sections. For example, for Windows
distributions, see *Note windows-installation::.

To obtain MySQL, see *Note getting-mysql::.

MySQL compressed `tar' file binary distributions have names of the form
`mysql-VERSION-OS.tar.gz', where `VERSION' is a number (for example,
`5.0.93'), and OS indicates the type of operating system for which the
distribution is intended (for example, `pc-linux-i686' or `winx64').

To install MySQL from a compressed `tar' file binary distribution, your
system must have GNU `gunzip' to uncompress the distribution and a
reasonable `tar' to unpack it. If your `tar' program supports the `z'
option, it can both uncompress and unpack the file.

GNU `tar' is known to work. The standard `tar' provided with some
operating systems is not able to unpack the long file names in the
MySQL distribution. You should download and install GNU `tar', or if
available, use a preinstalled version of GNU tar. Usually this is
available as `gnutar', `gtar', or as `tar' within a GNU or Free
Software directory, such as `/usr/sfw/bin' or `/usr/local/bin'. GNU
`tar' is available from `http://www.gnu.org/software/tar/'.

*Warning*:

If you have previously installed MySQL using your operating system
native package management system, such as `yum' or `apt-get', you may
experience problems installing using a native binary. Make sure your
previous MySQL previous installation has been removed entirely (using
your package management system), and that any additional files, such as
old versions of your data files, have also been removed. You should
also check the existence of configuration files such as `/etc/my.cnf'
or the `/etc/mysql' directory have been deleted.

If you run into problems and need to file a bug report, please use the
instructions in *Note bug-reports::.

To install and use a MySQL binary distribution, the basic command
sequence looks like this:

shell> groupadd mysql
shell> useradd -r -g mysql mysql
shell> cd /usr/local
shell> tar zxvf /PATH/TO/MYSQL-VERSION-OS.tar.gz
shell> ln -s FULL-PATH-TO-MYSQL-VERSION-OS mysql
shell> cd mysql
shell> chown -R mysql .
shell> chgrp -R mysql .
shell> scripts/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql data
# Next command is optional
shell> cp support-files/my-medium.cnf /etc/my.cnf
shell> bin/mysqld_safe --user=mysql &
# Next command is optional
shell> cp support-files/mysql.server /etc/init.d/mysql.server

A more detailed version of the preceding description for installing a
binary distribution follows.

*Note*:

This procedure assumes that you have `root' (administrator) access to
your system. Alternatively, you can prefix each command using the
`sudo' (Linux) or `pfexec' (OpenSolaris) command.

The procedure does not set up any passwords for MySQL accounts. After
following the procedure, proceed to *Note postinstallation::.

Create a `mysql' User and Group

If your system does not already have a user and group for *Note
`mysqld': mysqld. to run as, you may need to create one. The following
commands add the `mysql' group and the `mysql' user. The syntax for
`useradd' and `groupadd' may differ slightly on different versions of
Unix, or they may have different names such as `adduser' and `addgroup'.

shell> groupadd mysql
shell> useradd -r -g mysql mysql

*Note*:

Because the user is required only for ownership purposes, not login
purposes, the `useradd' command uses the `-r' option to create a user
that does not have login permissions to your server. Omit this option
to permit logins for the user (or if your `useradd' does not support
the option).

You might want to call the user and group something else instead of
`mysql'. If so, substitute the appropriate name in the preceding
commands and in the following steps.

Obtain and Unpack the Distribution

Pick the directory under which you want to unpack the distribution and
change location into it. The example here unpacks the distribution
under `/usr/local'. The instructions, therefore, assume that you have
permission to create files and directories in `/usr/local'. If that
directory is protected, you must perform the installation as `root'.

shell> cd /usr/local

Obtain a distribution file using the instructions in *Note
getting-mysql::. For a given release, binary distributions for all
platforms are built from the same MySQL source distribution.

Unpack the distribution, which creates the installation directory.
Then create a symbolic link to that directory. `tar' can uncompress
and unpack the distribution if it has `z' option support:

shell> tar zxvf /PATH/TO/MYSQL-VERSION-OS.tar.gz
shell> ln -s FULL-PATH-TO-MYSQL-VERSION-OS mysql

The `tar' command creates a directory named `mysql-VERSION-OS'. The
`ln' command makes a symbolic link to that directory. This enables you
to refer more easily to the installation directory as
`/usr/local/mysql'.

If your `tar' does not have `z' option support, use `gunzip' to unpack
the distribution and `tar' to unpack it. Replace the preceding `tar'
command with the following alternative command to uncompress and
extract the distribution:

shell> gunzip < /PATH/TO/MYSQL-VERSION-OS.tar.gz | tar xvf -

Perform Postinstallation Setup

The remainder of the installation process involves setting up the
configuration file, creating the core databases, and starting the MySQL
server. For instructions, see *Note postinstallation::.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

File: manual.info, Node: source-installation, Next: postinstallation, Prev: binary-installation, Up: installing

3.17 Installing MySQL from Source
=================================

* Menu:

* installing-source-distribution:: Installing MySQL from a Standard Source Distribution
* installing-development-tree:: Installing MySQL from a Development Source Tree
* source-configuration-options:: MySQL Source-Configuration Options
* compilation-problems:: Dealing with Problems Compiling MySQL
* compile-and-link-options:: Compiling and Linking an Optimized `mysqld' Server

Building MySQL from the source code enables you to customize build
parameters, compiler optimizations, and installation location. For a
list of systems on which MySQL is known to run, see *Note
supported-os::.

Before you proceed with an installation from source, check whether we
produce a precompiled binary distribution for your platform and whether
it works for you. We put a great deal of effort into ensuring that our
binaries are built with the best possible options for optimal
performance. Instructions for installing binary distributions are
available in *Note binary-installation::.

To obtain a source distribution for MySQL, see *Note getting-mysql::.
MySQL source distributions are available as compressed `tar' files, Zip
archives, or RPM packages. Distribution files have names of the form
`mysql-VERSION.tar.gz', `mysql-VERSION.zip', or `mysql-VERSION.rpm',
where VERSION is a number like `5.0.93'.

To perform a MySQL installation using the source code:

* To build MySQL from source on Unix-like systems, including Linux,
commercial Unix, BSD, Mac OS X and others using a `.tar.gz' or
RPM-based source code distribution, see *Note
installing-source-distribution::.

* To build MySQL from source on Windows (Windows XP or newer
required), see *Note windows-source-build::.

* For information on building from one of our development trees, see
*Note installing-development-tree::.

* For information on using the `configure' command to specify the
source build parameters, including links to platform specific
parameters that you might need, see *Note
source-configuration-options::.

To install MySQL from source, your system must have the following tools:

* GNU `gunzip' to uncompress the distribution and a reasonable `tar'
to unpack it (if you use a `.tar.gz' distribution), or `WinZip' or
another tool that can read `.zip' files (if you use a `.zip'
distribution).

GNU `tar' is known to work. The standard `tar' provided with some
operating systems is not able to unpack the long file names in the
MySQL distribution. You should download and install GNU `tar', or
if available, use a preinstalled version of GNU tar. Usually this
is available as `gnutar', `gtar', or as `tar' within a GNU or Free
Software directory, such as `/usr/sfw/bin' or `/usr/local/bin'.
GNU `tar' is available from `http://www.gnu.org/software/tar/'.

* A working ANSI C++ compiler. GCC 3.2 or later, Sun Studio 10 or
later, Visual Studio 2005 or later, and many current
vendor-supplied compilers are known to work.

* A good `make' program. Although some platforms come with their own
`make' implementations, it is highly recommended that you use GNU
`make' 3.75 or newer. It may already be available on your system as
`gmake'. GNU `make' is available from
`http://www.gnu.org/software/make/'.

* `libtool' 1.5, available from
`http://www.gnu.org/software/libtool/'. 1.5.24 or later is
recommended.

If you are using a version of `gcc' recent enough to understand the
`-fno-exceptions' option, it is _very important_ that you use this
option. Otherwise, you may compile a binary that crashes randomly.
Also use `-felide-constructors' and `-fno-rtti' along with
`-fno-exceptions'. When in doubt, do the following:

CFLAGS="-O3" CXX=gcc CXXFLAGS="-O3 -felide-constructors \
-fno-exceptions -fno-rtti" ./configure \
--prefix=/usr/local/mysql --enable-assembler \
--with-mysqld-ldflags=-all-static

On most systems, this gives you a fast and stable binary.

If you run into problems and need to file a bug report, please use the
instructions in *Note bug-reports::.

File: manual.info, Node: installing-source-distribution, Next: installing-development-tree, Prev: source-installation, Up: source-installation

3.17.1 Installing MySQL from a Standard Source Distribution
-----------------------------------------------------------

To install MySQL from source, first configure, build, and install from
a source package. Then follow the same postinstallation setup sequence
as for a binary installation.

If you start from a source RPM, use the following command to make a
binary RPM that you can install. If you do not have `rpmbuild', use
`rpm' instead.

shell> rpmbuild --rebuild --clean MySQL-VERSION.src.rpm

The result is one or more binary RPM packages that you install as
indicated in *Note linux-installation-rpm::.

The sequence for installation from a compressed `tar' file source
distribution is similar to the process for installing from a generic
binary distribution that is detailed in *Note binary-installation::.
For a MySQL `.tar.gz' source distribution, the basic installation
command sequence looks like this:

# Preconfiguration setup
shell> groupadd mysql
shell> useradd -g mysql mysql
# Beginning of source-build specific instructions
shell> tar zxvf mysql-VERSION.tar.gz
shell> cd mysql-VERSION
shell> ./configure --prefix=/usr/local/mysql
shell> make
shell> make install
# End of source-build specific instructions
# Postinstallation setup
shell> cd /usr/local/mysql
shell> chown -R mysql .
shell> chgrp -R mysql .
shell> bin/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql var
# Next command is optional
shell> cp support-files/my-medium.cnf /etc/my.cnf
shell> bin/mysqld_safe --user=mysql &
# Next command is optional
shell> cp support-files/mysql.server /etc/init.d/mysql.server

*Note*:

This procedure does not set up any passwords for MySQL accounts. After
following the procedure, proceed to *Note postinstallation::, for
postinstallation setup and testing.

A more detailed version of the preceding description for installing
MySQL from a source distribution follows:

1. Add a login user and group for *Note `mysqld': mysqld. to run as:

shell> groupadd mysql
shell> useradd -g mysql mysql

These commands add the `mysql' group and the `mysql' user. The
syntax for `useradd' and `groupadd' may differ slightly on
different versions of Unix, or they may have different names such
as `adduser' and `addgroup'.

You might want to call the user and group something else instead
of `mysql'. If so, substitute the appropriate name in the
following steps.

2. Perform the following steps as the `mysql' user, except as noted.

3. Pick the directory under which you want to unpack the distribution
and change location into it.

4. Obtain a distribution file using the instructions in *Note
getting-mysql::.

5. Unpack the distribution into the current directory. `tar' can
uncompress and unpack the distribution if it has `z' option
support:

shell> tar zxvf /PATH/TO/MYSQL-VERSION.tar.gz

This command creates a directory named `mysql-VERSION'.

If your `tar' does not have `z' option support, use `gunzip' to
unpack the distribution and `tar' to unpack it:

shell> gunzip < /PATH/TO/MYSQL-VERSION.tar.gz | tar xvf -

6. Change location into the top-level directory of the unpacked
distribution:

shell> cd mysql-VERSION

Note that currently you must configure and build MySQL from this
top-level directory. You cannot build it in a different directory.

7. Configure the release and compile everything:

shell> ./configure --prefix=/usr/local/mysql
shell> make

When you run `configure', you might want to specify other options.
For example, if you need to debug *Note `mysqld': mysqld. or a
MySQL client, run `configure' with the `--with-debug' option, and
then recompile and link your clients with the new client library.
See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

Run `./configure --help' for a list of options. *Note
source-configuration-options::, discusses some of the more useful
options.

If `configure' fails and you are going to send mail to a MySQL
mailing list to ask for assistance, please include any lines from
`config.log' that you think can help solve the problem. Also
include the last couple of lines of output from `configure'. To
file a bug report, please use the instructions in *Note
bug-reports::.

If the compile fails, see *Note compilation-problems::, for help.

8. Install the distribution:

shell> make install

You might need to run this command as `root'.

If you want to set up an option file, use one of those present in
the `support-files' directory as a template. For example:

shell> cp support-files/my-medium.cnf /etc/my.cnf

You might need to run this command as `root'.

If you want to configure support for `InnoDB' tables, you should
edit the `/etc/my.cnf' file, removing the `#' character before the
option lines that start with `innodb_...', and modify the option
values to be what you want. See *Note option-files::, and *Note
innodb-configuration::.

9. Change location into the installation directory:

shell> cd /usr/local/mysql

10. If you ran the `make install' command as `root', the installed
files will be owned by `root'. Ensure that the installation is
accessible to `mysql' by executing the following commands as
`root' in the installation directory:

shell> chown -R mysql .
shell> chgrp -R mysql .

The first command changes the owner attribute of the files to the
`mysql' user. The second changes the group attribute to the
`mysql' group.

11. If you have not installed MySQL before, you must create the MySQL
data directory and initialize the grant tables:

shell> bin/mysql_install_db --user=mysql

If you run the command as `root', include the `--user' option as
shown. If you run the command while logged in as `mysql', you can
omit the `--user' option.

The command should create the data directory and its contents with
`mysql' as the owner.

After using *Note `mysql_install_db': mysql-install-db. to create
the grant tables for MySQL, you must restart the server manually.
The *Note `mysqld_safe': mysqld-safe. command to do this is shown
in a later step.

12. Most of the MySQL installation can be owned by `root' if you like.
The exception is that the data directory must be owned by `mysql'.
To accomplish this, run the following commands as `root' in the
installation directory:

shell> chown -R root .
shell> chown -R mysql var

13. If the plugin directory is writable by the server, it may be
possible for a user to write executable code to a file in the
directory using *Note `SELECT ... INTO DUMPFILE': select. This can
be prevented by making `plugin_dir' read only to the server or by
setting `--secure-file-priv' to a directory where *Note `SELECT':
select. writes can be made safely.

14. If you want MySQL to start automatically when you boot your
machine, you can copy `support-files/mysql.server' to the location
where your system has its startup files. More information can be
found in the `support-files/mysql.server' script itself; see also
*Note automatic-start::.

15. You can set up new accounts using the `bin/mysql_setpermission'
script if you install the `DBI' and `DBD::mysql' Perl modules. See
*Note mysql-setpermission::. For Perl module installation
instructions, see *Note perl-support::.

After everything has been installed, test the distribution. To start
the MySQL server, use the following command:

shell> /usr/local/mysql/bin/mysqld_safe --user=mysql &

If you run the command as `root', you should use the `--user' option as
shown. The option value is the name of the login account that you
created in the first step to use for running the server. If you run the
*Note `mysqld_safe': mysqld-safe. command while logged in as that user,
you can omit the `--user' option.

If the command fails immediately and prints `mysqld ended', look for
information in the error log (which by default is the `HOST_NAME.err'
file in the data directory).

More information about *Note `mysqld_safe': mysqld-safe. is given in
*Note mysqld-safe::.

To make it more convenient to invoke programs installed in
`/usr/local/mysql/bin', you can add that directory to your `PATH'
environment variable setting. That enables you to run a program by
typing only its name, not its entire path name. See *Note
setting-environment-variables::.

*Note*:

The accounts that are listed in the MySQL grant tables initially have
no passwords. After starting the server, you should set up passwords
for them using the instructions in *Note postinstallation::.

File: manual.info, Node: installing-development-tree, Next: source-configuration-options, Prev: installing-source-distribution, Up: source-installation

3.17.2 Installing MySQL from a Development Source Tree
------------------------------------------------------

This section discusses how to install MySQL from the latest development
source code. Development trees have not necessarily received the same
level of testing as standard release distributions, so this
installation method is usually required only if you need the most
recent code changes. Do not use a development tree for production
systems. If your goal is simply to get MySQL up and running on your
system, you should use a standard release distribution (either a binary
or source distribution). See *Note getting-mysql::.

To obtain the source tree, you must have Bazaar installed. The Bazaar
VCS Web site (http://bazaar-vcs.org) has instructions for downloading
and installing Bazaar on different platforms. Bazaar is supported on
any platform that supports Python, and is therefore compatible with any
Linux, Unix, Windows, or Mac OS X host.

MySQL development projects are hosted on Launchpad
(http://launchpad.net/). MySQL projects, including MySQL Server, MySQL
Workbench, and others are available from the Oracle/MySQL Engineering
(http://launchpad.net/~mysql) page. For the repositories related only to
MySQL Server, see the MySQL Server (http://launchpad.net/mysql-server)
page.

For information about using Bazaar with MySQL, see
`http://forge.mysql.com/wiki/MySQL_Bazaar_Howto'.

To build under Unix/Linux, you must have the following tools installed:

* A good `make' program. Although some platforms come with their own
`make' implementations, it is highly recommended that you use GNU
`make' 3.75 or newer. It may already be available on your system
as `gmake'. GNU `make' is available from
`http://www.gnu.org/software/make/'.

* `autoconf' 2.58 (or newer), available from
`http://www.gnu.org/software/autoconf/'.

* `automake' 1.8.1, available from
`http://www.gnu.org/software/automake/'.

* `libtool' 1.5, available from
`http://www.gnu.org/software/libtool/'. 1.5.24 or later is
recommended.

* `m4', available from `http://www.gnu.org/software/m4/'.

* `bison', available from `http://www.gnu.org/software/bison/'. You
should use the latest version of `bison' where possible. Versions
1.75 and 2.1 are known to work. There have been reported problems
with `bison' 1.875. If you experience problems, upgrade to a
later, rather than earlier, version.

To build under Windows you must have Microsoft Visual C++ 2005 Express
Edition, Visual Studio .Net 2003 (7.1), or Visual Studio 2005 (8.0)
compiler system.

Once the necessary tools are installed, create a local branch of the
MySQL development tree on your machine using this procedure:

1. To obtain a copy of the MySQL source code, you must create a new
Bazaar branch. If you do not already have a Bazaar repository
directory set up, you must initialize a new directory:

shell> mkdir mysql-server
shell> bzr init-repo --trees mysql-server

This is a one-time operation.

2. Assuming that you have an initialized repository directory, you
can branch from the public MySQL server repositories to create a
local source tree. To create a branch of a specific version:

shell> cd mysql-server
shell> bzr branch lp:mysql-server/5.0 mysql-5.0

This is a one-time operation per source tree. You can branch the
source trees for several versions of MySQL under the
`mysql-server' directory.

3. The initial download will take some time to complete, depending on
the speed of your connection. Please be patient. Once you have
downloaded the first tree, additional trees should take
significantly less time to download.

4. When building from the Bazaar branch, you may want to create a
copy of your active branch so that you can make configuration and
other changes without affecting the original branch contents. You
can achieve this by branching from the original branch:

shell> bzr branch mysql-5.0 mysql-5.0-build

5. To obtain changes made after you have set up the branch initially,
update it using the `pull' option periodically. Use this command
in the top-level directory of the local copy:

shell> bzr pull

You can examine the changeset comments for the tree by using the
`log' option to `bzr':

shell> bzr log

You can also browse changesets, comments, and source code online
at the Launchpad MySQL Server (http://launchpad.net/mysql-server)
page.

If you see diffs (changes) or code that you have a question about,
do not hesitate to send email to the MySQL `internals' mailing
list. See *Note mailing-lists::. If you think you have a better
idea on how to do something, send an email message to the list
with a patch.

After you have the local branch, you can build MySQL server from the
source code. On Windows, the build process is different from
Unix/Linux: see *Note windows-source-build::.

On Unix/Linux, use the `autoconf' system to create the `configure'
script so that you can configure the build environment before building.
The following example shows the typical commands required to build
MySQL from a source tree.

1. Change location to the top-level directory of the source tree;
replace `mysql-5.0' with the appropriate directory name.

shell> cd mysql-5.0

2. Prepare the source tree for configuration.

You must separately configure the `BDB' and `InnoDB' storage
engines. Run the following commands from the main source directory:

shell> (cd bdb/dist; sh s_all)
shell> (cd innobase; autoreconf --force --install)

You can omit the previous commands if you do not require `BDB' or
`InnoDB' support.

Prepare the remainder of the source tree:

shell> autoreconf --force --install

As an alternative to the preceding `autoreconf' command, you can
use `BUILD/autorun.sh', which acts as a shortcut for the following
sequence of commands:

shell> aclocal; autoheader
shell> libtoolize --automake --force
shell> automake --force --add-missing; autoconf
shell> (cd bdb/dist; sh s_all)
shell> (cd innobase; aclocal; autoheader; autoconf; automake)

If you get some strange errors during this stage, verify that you
have the correct version of `libtool' installed.

3. Configure the source tree and compile MySQL:

shell> ./configure # Add your favorite options here
shell> make

For a description of some `configure' options, see *Note
source-configuration-options::.

A collection of configuration scripts is located in the `BUILD/'
subdirectory. For example, you may find it more convenient to use
the `BUILD/compile-pentium-debug' script than the preceding set of
shell commands. To compile on a different architecture, modify the
script by removing flags that are Pentium-specific, or use another
script that may be more appropriate. These scripts are provided on
an `as-is' basis. They are not supported and their contents may
change from release to release.

4. When the build is done, run `make install'. Be careful with this
on a production machine; the installation command may overwrite
your live release installation. If you already have MySQL
installed and do not want to overwrite it, run `./configure' with
values for the `--prefix', `--with-tcp-port', and
`--with-unix-socket-path' options different from those used by
your production server. For additional information about
preventing multiple servers from interfering with each other, see
*Note multiple-servers::.

5. Play hard with your new installation. For example, try to make new
features crash. Start by running `make test'. See *Note
mysql-test-suite::.

6. If you have gotten to the `make' stage, but the distribution does
not compile, please enter the problem into our bugs database using
the instructions given in *Note bug-reports::. If you have
installed the latest versions of the required tools, and they
crash trying to process our configuration files, please report
that also. However, if you get a `command not found' error or a
similar problem for required tools, do not report it. Instead,
make sure that all the required tools are installed and that your
`PATH' variable is set correctly so that your shell can find them.

File: manual.info, Node: source-configuration-options, Next: compilation-problems, Prev: installing-development-tree, Up: source-installation

3.17.3 MySQL Source-Configuration Options
-----------------------------------------

The `configure' script provides a great deal of control over how you
configure a MySQL source distribution. Typically, you do this using
options on the `configure' command line. For a full list of options
supported by `configure', run this command:

shell> ./configure --help

You can also affect `configure' using certain environment variables. See
*Note environment-variables::.

The following table shows the available `configure' options.

*MySQL Source-Configuration Option Reference (`configure')*

Formats Description Default IntroducedRemoved
`--bindir=DIR' User executables `EPREFIX/bin'
`--build=BUILD' Configure for `guessed'
building on BUILD
`--cache-file=FILE' Cache test results in `disabled'
FILE
`-C' Alias for `'
`-cache-file=config.cache'
`--config-cache'
`--datadir=DIR' Read-only `PREFIX/share'
architecture-independent
data
`--disable-FEATURE' Do not include FEATURE `'
`--disable-dependency-tracking'Disable dependency `'
tracking
`--disable-grant-options'Disable GRANT options `' 5.0.34
`--disable-largefile' Omit support for `'
large files
`--disable-libtool-lock'Disable libtool lock `'
`--disable-profiling' Build a version `' 5.0.37 5.0.45
without query
profiling code
`--enable-FEATURE' Enable FEATURE `'
`--enable-assembler' Use assembler `'
versions of some
string functions if
available
`--enable-dependency-tracking'Do not reject slow `'
dependency extractors
`--enable-fast-install'Optimize for fast `yes'
installation
`--enable-local-infile'Enable LOCAL for LOAD `disabled'
DATA INFILE
`--enable-shared' Build shared libraries `yes'
`--enable-static' Build static libraries `yes'
`--enable-thread-safe-client'Compile the client `'
with threads
`--exec-prefix=EPREFIX'Install `'
architecture-dependent
files in EPREFIX
`-h' Display this help and `'
exit
`--help'
`--help=short' Display options
specific to this
package
`--help=recursive' Display the short
help of all the
included packages
`--host=HOST' Cross-compile to `'
build programs to run
on HOST
`--includedir=DIR' C header files `PREFIX/include'
`--infodir=DIR' Info documentation `PREFIX/info'
`--libdir=DIR' Object code libraries `EPREFIX/lib'
`--libexecdir=DIR' Program executables `EPREFIX/libexec'
`--localstatedir=DIR' Modifiable `PREFIX/var'
single-machine data
`--mandir=DIR' man documentation `PREFIX/man'
`-n' Do not create output `'
files
`--no-create'
`--oldincludedir=DIR' C header files for `/usr/include'
non-gcc
`--prefix=PREFIX' Install `'
architecture-independent
files in PREFIX
`--program-prefix=PREFIX'Prepend PREFIX to `'
installed program
names
`--program-suffix=SUFFIX'Append SUFFIX to `'
installed program
names
`--program-transform-name=PROGRAM'run sed PROGRAM on `'
installed program
names
`-q' Do not print `'
`checking...' messages
`--quiet'
`--sbindir=DIR' System administrative `EPREFIX/sbin'
executables
`--sharedstatedir=DIR' Modifiable `PREFIX/com'
architecture-independent
data
`--srcdir=DIR' Find the sources in `configure
DIR directory or
..'
`--sysconfdir=DIR' Read-only `PREFIX/etc'
single-machine data
`--target=TARGET' Configure for `'
building compilers
for TARGET
`-V' Display version `'
information and exit
`--version'
`--with-PACKAGE' Use PACKAGE `'
`--with-archive-storage-engine'Enable the Archive `no'
Storage Engine
`--with-berkeley-db' Use BerkeleyDB `no'
located in DIR
`--with-berkeley-db-includes'Find Berkeley DB `'
headers in DIR
`--with-berkeley-db-libs'Find Berkeley DB `'
libraries in DIR
`--with-big-tables' Support tables with `' 5.0.4
more than 4 G rows
even on 32 bit
platforms
`--with-blackhole-storage-engine'Enable the Blackhole `no' 5.0.4
Storage Engine
`--with-charset' Default character set `'
`--with-client-ldflags'Extra linking `'
arguments for clients
`--with-collation' Default collation `'
`--with-comment' Comment about `'
compilation
environment
`--with-csv-storage-engine'Enable the CSV `yes'
Storage Engine
`--with-darwin-mwcc' Use Metrowerks `' 5.0.6
CodeWarrior wrappers
on OS X/Darwin
`--with-embedded-privilege-control'Build parts to check `'
user's privileges
(only affects
embedded library)
`--with-embedded-server'Build the embedded `'
server
`--with-example-storage-engine'Enable the Example `no'
Storage Engine
`--with-extra-charsets'Use charsets in `'
addition to default
`--with-gnu-ld' Assume the C compiler `no'
uses GNU ld
`--with-isam' Enable the ISAM table `' 5.0.2
type
`--with-lib-ccflags' Extra CC options for `'
libraries
`--with-libwrap=DIR' Compile in libwrap `'
(tcp_wrappers) support
`--with-low-memory' Try to use less `'
memory to compile to
avoid memory
limitations
`--with-machine-type' Set the machine type, `' 5.0.44
like "powerpc"
`--with-max-indexes=N' Sets the maximum `64'
number of indexes per
table
`--with-mit-threads' Always use included `' 5.0.4
thread lib
`--with-mysqld-ldflags'Extra linking `'
arguments for mysqld
`--with-mysqld-libs' Extra libraries to `' 5.0.44
link with for mysqld
`--with-mysqld-user' What user the mysqld `'
daemon shall be run as
`--with-mysqlfs' Include the `' 5.0.3
corba-based MySQL
file system
`--with-mysqlmanager' Build the `Build if
mysqlmanager binary server is
built'
`--with-named-curses-libs'Use specified curses `'
libraries
`--with-named-thread-libs'Use specified thread `'
libraries
`--with-ndb-ccflags' Extra CC options for `' 5.0.3
ndb compile
`--with-ndb-docs' Include the NDB `'
Cluster ndbapi and
mgmapi documentation
`--with-ndb-port' Port for NDB Cluster `'
management server
`--with-ndb-port-base' Port for NDB Cluster `' 5.0.3
management server
`--with-ndb-sci=DIR' Provide MySQL with a `'
custom location of
sci library
`--with-ndb-shm' Include the NDB `' 5.0.2
Cluster shared memory
transporter
`--with-ndb-test' Include the NDB `'
Cluster ndbapi test
programs
`--with-ndbcluster' Include the NDB `no'
Cluster table handler
`--with-openssl=DIR' Include the OpenSSL `'
support
`--with-openssl-includes'Find OpenSSL headers `'
in DIR
`--with-openssl-libs' Find OpenSSL `'
libraries in DIR
`--with-other-libc=DIR'Link against libc and `'
other standard
libraries installed in
the specified
nonstandard location
`--with-pic' Try to use only `Use both'
PIC/non-PIC objects
`--with-pstack' Use the pstack `'
backtrace library
`--with-pthread' Force use of pthread `'
library
`--with-raid' Enable RAID Support `' 5.0.3
`--with-server-suffix' Append value to the `'
version string
`--with-system-type' Set the system type, `' 5.0.44
like "sun-solaris10"
`--with-tags' Include additional `automatic'
configurations
`--with-tcp-port' Which port to use for `3306'
MySQL services
`--with-unix-socket-path'Where to put the `'
unix-domain socket
`--with-vio' Include the Virtual `' 5.0.2
IO support
`--with-yassl' Include the yaSSL `' 5.0.6
support
`--with-zlib-dir=no|bundled|DIR'Provide MySQL with a `'
custom location of
compression library
`--without-PACKAGE' Do not use PACKAGE `'
`--without-bench' Skip building of the `'
benchmark suite
`--without-debug' Build a production `'
version without
debugging code
`--without-docs' Skip building of the `'
documentation
`--without-extra-tools'Skip building `'
utilities in the
tools directory
`--without-geometry' Do not build `'
geometry-related parts
`--without-innodb' Do not include the `' 5.0.48
InnoDB table handler
`--without-libedit' Use system libedit `'
instead of bundled
copy
`--without-man' Skip building of the `'
man pages
`--without-ndb-debug' Disable special ndb `' 5.0.3
debug features
`--without-query-cache'Do not build query `'
cache
`--without-readline' Use system readline `'
instead of bundled
copy
`--without-server' Only build the client `'
`--without-uca' Skip building of the `' 5.0.3
national Unicode
collations

Some of the `configure' options available are described here. For
options that may be of use if you have difficulties building MySQL, see
*Note compilation-problems::.

Many options configure compile-time defaults that can be overridden at
server startup. For example, the `--prefix', `--with-tcp-port', and
`with-unix-socket-path' options that configure the default installation
base directory location, TCP/IP port number, and Unix socket file can
be changed at server startup with the `--basedir', `--port', and
`--socket' options for *Note `mysqld': mysqld.

* To compile just the MySQL client libraries and client programs
and not the server, use the `--without-server' option:

shell> ./configure --without-server

If you have no C++ compiler, some client programs such as *Note
`mysql': mysql. cannot be compiled because they require C++. In
this case, you can remove the code in `configure' that tests for
the C++ compiler and then run `./configure' with the
`--without-server' option. The compile step should still try to
build all clients, but you can ignore any warnings about files
such as `mysql.cc'. (If `make' stops, try `make -k' to tell it to
continue with the rest of the build even if errors occur.)

* To build the embedded MySQL library (`libmysqld.a'), use the
`--with-embedded-server' option.

* To place your log files and database directories elsewhere than
under `/usr/local/var', use a `configure' command something like
one of these:

shell> ./configure --prefix=/usr/local/mysql
shell> ./configure --prefix=/usr/local \
--localstatedir=/usr/local/mysql/data

The first command changes the installation prefix so that
everything is installed under `/usr/local/mysql' rather than the
default of `/usr/local'. The second command preserves the default
installation prefix, but overrides the default location for
database directories (normally `/usr/local/var') and changes it to
`/usr/local/mysql/data'.

You can also specify the installation directory and data directory
locations at server startup time by using the `--basedir' and
`--datadir' options. These can be given on the command line or in
an MySQL option file, although it is more common to use an option
file. See *Note option-files::.

* The `--with-tcp-port' option specifies the port number on which
the server listens for TCP/IP connections. The default is port
3306. To listen on a different port, use a `configure' command
like this:

shell> ./configure --with-tcp-port=3307

* On Unix, if you want the MySQL socket file location to be
somewhere other than the default location (normally in the
directory `/tmp' or `/var/run'), use a `configure' command like
this:

shell> ./configure \
--with-unix-socket-path=/usr/local/mysql/tmp/mysql.sock

The socket file name must be an absolute path name. You can also
change the location of `mysql.sock' at server startup by using a
MySQL option file. See *Note problems-with-mysql-sock::.

* To compile statically linked programs (for example, to make a
binary distribution, to get better performance, or to work around
problems with some Red Hat Linux distributions), run `configure'
like this:

shell> ./configure --with-client-ldflags=-all-static \
--with-mysqld-ldflags=-all-static

* If you are using `gcc' and do not have `libg++' or `libstdc++'
installed, you can tell `configure' to use `gcc' as your C++
compiler:

shell> CC=gcc CXX=gcc ./configure

When you use `gcc' as your C++ compiler, it does not attempt to
link in `libg++' or `libstdc++'. This may be a good thing to do
even if you have those libraries installed. Some versions of them
have caused strange problems for MySQL users in the past.

The following list indicates some compilers and environment
variable settings that are commonly used with each one.

* `gcc' 2.7.2:

CC=gcc CXX=gcc CXXFLAGS="-O3 -felide-constructors"

* `gcc' 2.95.2:

CFLAGS="-O3 -mpentiumpro" CXX=gcc CXXFLAGS="-O3 -mpentiumpro \
-felide-constructors -fno-exceptions -fno-rtti"

In most cases, you can get a reasonably optimized MySQL binary by
using the options from the preceding list and adding the following
options to the `configure' line:

--prefix=/usr/local/mysql --enable-assembler \
--with-mysqld-ldflags=-all-static

The full `configure' line would, in other words, be something like
the following for all recent `gcc' versions:

CFLAGS="-O3 -mpentiumpro" CXX=gcc CXXFLAGS="-O3 -mpentiumpro \
-felide-constructors -fno-exceptions -fno-rtti" ./configure \
--prefix=/usr/local/mysql --enable-assembler \
--with-mysqld-ldflags=-all-static

The binaries we provide on the MySQL Web site at
`http://dev.mysql.com/downloads/' are all compiled with full
optimization and should work well for most users. See *Note
binary-installation::.

* If the build fails and produces errors about your compiler or
linker not being able to create the shared library
`libmysqlclient.so.N' (where N is a version number), you can work
around this problem by giving the `--disable-shared' option to
`configure'. In this case, `configure' does not build a shared
`libmysqlclient.so.N' library.

* By default, MySQL uses the `latin1' (cp1252 West European)
character set. To change the default set, use the `--with-charset'
option:

shell> ./configure --with-charset=CHARSET

CHARSET may be one of `binary', `armscii8', `ascii', `big5',
`cp1250', `cp1251', `cp1256', `cp1257', `cp850', `cp852', `cp866',
`cp932', `dec8', `eucjpms', `euckr', `gb2312', `gbk', `geostd8',
`greek', `hebrew', `hp8', `keybcs2', `koi8r', `koi8u', `latin1',
`latin2', `latin5', `latin7', `macce', `macroman', `sjis', `swe7',
`tis620', `ucs2', `ujis', `utf8'. (Additional character sets might
be available. Check the output from `./configure --help' for the
current list.)

The default collation may also be specified. MySQL uses the
`latin1_swedish_ci' collation by default. To change this, use the
`--with-collation' option:

shell> ./configure --with-collation=COLLATION

To change both the character set and the collation, use both the
`--with-charset' and `--with-collation' options. The collation
must be a legal collation for the character set. (Use the *Note
`SHOW COLLATION': show-collation. statement to determine which
collations are available for each character set.)

With the `configure' option `--with-extra-charsets=LIST', you can
define which additional character sets should be compiled into the
server. LIST is one of the following:

* A list of character set names separated by spaces

* `complex' to include all character sets that can't be
dynamically loaded

* `all' to include all character sets into the binaries

Clients that want to convert characters between the server and the
client should use the `SET NAMES' statement. See *Note
charset-connection::.

* To configure MySQL with debugging code, use the `--with-debug'
option:

shell> ./configure --with-debug

This causes a safe memory allocator to be included that can find
some errors and that provides output about what is happening. See
MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

As of MySQL 5.0.25, using `--with-debug' to configure MySQL with
debugging support enables you to use the
`--debug="d,parser_debug"' option when you start the server. This
causes the Bison parser that is used to process SQL statements to
dump a parser trace to the server's standard error output.
Typically, this output is written to the error log.

* If your client programs are using threads, you must compile a
thread-safe version of the MySQL client library with the
`--enable-thread-safe-client' configure option. This creates a
`libmysqlclient_r' library with which you should link your
threaded applications. See *Note threaded-clients::.

* Some features require that the server be built with compression
library support, such as the `COMPRESS()' and `UNCOMPRESS()'
functions, and compression of the client/server protocol. The
`--with-zlib-dir=no|bundled|DIR' option provides control over
compression library support. The value `no' explicitly disables
compression support. `bundled' causes the `zlib' library bundled
in the MySQL sources to be used. A DIR path name specifies the
directory in which to find the compression library sources.

* It is possible to build MySQL 5.0 with large table support using
the `--with-big-tables' option, beginning with MySQL 5.0.4.

This option causes the variables that store table row counts to be
declared as `unsigned long long' rather than `unsigned long'. This
enables tables to hold up to approximately 1.844E+19 ((2^32)^2)
rows rather than 2^32 (~4.295E+09) rows. Previously it was
necessary to pass `-DBIG_TABLES' to the compiler manually in order
to enable this feature.

* Run `configure' with the `--disable-grant-options' option to
cause the `--bootstrap', `--skip-grant-tables', and `--init-file'
options for *Note `mysqld': mysqld. to be disabled. For Windows,
the `configure.js' script recognizes the `DISABLE_GRANT_OPTIONS'
flag, which has the same effect. The capability is available as of
MySQL 5.0.34.

* In MySQL Community Server, this option enables the statement
profiling capability exposed by the *Note `SHOW PROFILE':
show-profile. and *Note `SHOW PROFILES': show-profiles.
statements. (See *Note show-profiles::.) The option was added in
MySQL 5.0.37.

* See *Note operating-system-specific-notes::, for options that
pertain to particular operating systems.

* See *Note secure-using-ssl::, for options that pertain to
configuring MySQL to support secure (encrypted) connections.

File: manual.info, Node: compilation-problems, Next: compile-and-link-options, Prev: source-configuration-options, Up: source-installation

3.17.4 Dealing with Problems Compiling MySQL
--------------------------------------------

All MySQL programs compile cleanly for us with no warnings on Solaris
or Linux using `gcc'. On other systems, warnings may occur due to
differences in system include files. For other problems, check the
following list.

The solution to many problems involves reconfiguring. If you do need to
reconfigure, take note of the following:

* If `configure' is run after it has previously been run, it may use
information that was gathered during its previous invocation. This
information is stored in `config.cache'. When `configure' starts
up, it looks for that file and reads its contents if it exists, on
the assumption that the information is still correct. That
assumption is invalid when you reconfigure.

* Each time you run `configure', you must run `make' again to
recompile. However, you may want to remove old object files from
previous builds first because they were compiled using different
configuration options.

To prevent old configuration information or object files from being
used, run these commands before re-running `configure':

shell> rm config.cache
shell> make clean

Alternatively, you can run `make distclean'.

The following list describes some of the problems that have been found
to occur most often when compiling MySQL:

* If you get errors such as the ones shown here when compiling
`sql_yacc.cc', you probably have run out of memory or swap space:

Internal compiler error: program cc1plus got fatal signal 11
Out of virtual memory
Virtual memory exhausted

The problem is that `gcc' requires a huge amount of memory to
compile `sql_yacc.cc' with inline functions. Try running
`configure' with the `--with-low-memory' option:

shell> ./configure --with-low-memory

This option causes `-fno-inline' to be added to the compile line
if you are using `gcc' and `-O0' if you are using something else.
You should try the `--with-low-memory' option even if you have so
much memory and swap space that you think you can't possibly have
run out. This problem has been observed to occur even on systems
with generous hardware configurations, and the `--with-low-memory'
option usually fixes it.

* By default, `configure' picks `c++' as the compiler name and GNU
`c++' links with `-lg++'. If you are using `gcc', that behavior
can cause problems during configuration such as this:

configure: error: installation or configuration problem:
C++ compiler cannot create executables.

You might also observe problems during compilation related to
`g++', `libg++', or `libstdc++'.

One cause of these problems is that you may not have `g++', or you
may have `g++' but not `libg++', or `libstdc++'. Take a look at the
`config.log' file. It should contain the exact reason why your C++
compiler did not work. To work around these problems, you can use
`gcc' as your C++ compiler. Try setting the environment variable
`CXX' to `"gcc -O3"'. For example:

shell> CXX="gcc -O3" ./configure

This works because `gcc' compiles C++ source files as well as
`g++' does, but does not link in `libg++' or `libstdc++' by
default.

Another way to fix these problems is to install `g++', `libg++',
and `libstdc++'. However, do not use `libg++' or `libstdc++' with
MySQL because this only increases the binary size of *Note
`mysqld': mysqld. without providing any benefits. Some versions of
these libraries have also caused strange problems for MySQL users
in the past.

* To define flags to be used by your C or C++ compilers, specify
them using the `CFLAGS' and `CXXFLAGS' environment variables. You
can also specify the compiler names this way using `CC' and `CXX'.
For example:

shell> CC=gcc
shell> CFLAGS=-O3
shell> CXX=gcc
shell> CXXFLAGS=-O3
shell> export CC CFLAGS CXX CXXFLAGS

* If you get errors such as those shown here when compiling *Note
`mysqld': mysqld, `configure' did not correctly detect the type of
the last argument to `accept()', `getsockname()', or
`getpeername()':

cxx: Error: mysqld.cc, line 645: In this statement, the referenced
type of the pointer value ''length'' is ''unsigned long'',
which is not compatible with ''int''.
new_sock = accept(sock, (struct sockaddr *)&cAddr, &length);

To fix this, edit the `config.h' file (which is generated by
`configure'). Look for these lines:

/* Define as the base type of the last arg to accept */
#define SOCKET_SIZE_TYPE XXX

Change `XXX' to `size_t' or `int', depending on your operating
system. (You must do this each time you run `configure' because
`configure' regenerates `config.h'.)

* If your compile fails with errors such as any of the following,
you must upgrade your version of `make' to GNU `make':

make: Fatal error in reader: Makefile, line 18:
Badly formed macro assignment

Or:

make: file `Makefile' line 18: Must be a separator (:

Or:

pthread.h: No such file or directory

Solaris and FreeBSD are known to have troublesome `make' programs.

GNU `make' 3.75 is known to work.

* The `sql_yacc.cc' file is generated from `sql_yacc.yy'. Normally,
the build process does not need to create `sql_yacc.cc' because
MySQL comes with a pregenerated copy. However, if you do need to
re-create it, you might encounter this error:

"sql_yacc.yy", line XXX fatal: default action causes potential...

This is a sign that your version of `yacc' is deficient. You
probably need to install `bison' (the GNU version of `yacc') and
use that instead.

Versions of `bison' older than 1.75 may report this error:

sql_yacc.yy:#####: fatal error: maximum table size (32767) exceeded

The maximum table size is not actually exceeded; the error is
caused by bugs in older versions of `bison'.

* On Debian Linux 3.0, you need to install `gawk' instead of the
default `mawk' if you want to compile MySQL with Berkeley DB
support.

* If you get a compilation error on Linux (for example, SuSE Linux
8.1 or Red Hat Linux 7.3) similar to the following one, you
probably do not have `g++' installed:

libmysql.c:1329: warning: passing arg 5 of `gethostbyname_r' from
incompatible pointer type
libmysql.c:1329: too few arguments to function `gethostbyname_r'
libmysql.c:1329: warning: assignment makes pointer from integer
without a cast
make[2]: *** [libmysql.lo] Error 1

By default, the `configure' script attempts to determine the
correct number of arguments by using `g++' (the GNU C++ compiler).
This test yields incorrect results if `g++' is not installed.
There are two ways to work around this problem:

* Make sure that the GNU C++ `g++' is installed. On some Linux
distributions, the required package is called `gpp'; on
others, it is named `gcc-c++'.

* Use `gcc' as your C++ compiler by setting the `CXX'
environment variable to `gcc':

export CXX="gcc"

You must run `configure' again after making either of those
changes.

For information about acquiring or updating tools, see the system
requirements in *Note source-installation::.

File: manual.info, Node: compile-and-link-options, Prev: compilation-problems, Up: source-installation

3.17.5 Compiling and Linking an Optimized `mysqld' Server
---------------------------------------------------------

Most of the following tests were performed on Linux with the MySQL
benchmarks, but they should give some indication for other operating
systems and workloads.

You obtain the fastest executables when you link with `-static'.

By using better compiler and compilation options, you can obtain a 10%
to 30% speed increase in applications. This is particularly important
if you compile the MySQL server yourself.

When we tested both the Cygnus CodeFusion and Fujitsu compilers,
neither was sufficiently bug-free to enable MySQL to be compiled with
optimizations enabled.

The standard MySQL binary distributions are compiled with support for
all character sets. When you compile MySQL yourself, you should include
support only for the character sets that you are going to use. This is
controlled by the `--with-charset' option to `configure'.

Here is a list of some measurements that we have made:

* If you link dynamically (without `-static'), the result is 13%
slower on Linux. Note that you still can use a dynamically linked
MySQL library for your client applications. It is the server that
is most critical for performance.

* For a connection from a client to a server running on the same
host, if you connect using TCP/IP rather than a Unix socket file,
performance is 7.5% slower. (On Unix, if you connect to the host
name `localhost', MySQL uses a socket file by default.)

* For TCP/IP connections from a client to a server, connecting to a
remote server on another host is 8% to 11% slower than connecting
to a server on the same host, even for connections faster than
100Mb/s Ethernet.

* When running our benchmark tests using secure connections (all
data encrypted with internal SSL support) performance was 55%
slower than with unencrypted connections.

* If you compile with `--with-debug=full', most queries are 20%
slower. Some queries may take substantially longer; for example,
the MySQL benchmarks run 35% slower. If you use `--with-debug'
(without `=full'), the speed decrease is only 15%. For a version
of *Note `mysqld': mysqld. that has been compiled with
`--with-debug=full', you can disable memory checking at runtime by
starting it with the `--skip-safemalloc' option. The execution
speed should then be close to that obtained when configuring with
`--with-debug'.

* On a Sun UltraSPARC-IIe, a server compiled with Forte 5.0 is 4%
faster than one compiled with `gcc' 3.2.

* On a Sun UltraSPARC-IIe, a server compiled with Forte 5.0 is 4%
faster in 32-bit mode than in 64-bit mode.

* Compiling with `gcc' 2.95.2 for UltraSPARC with the `-mcpu=v8
-Wa,-xarch=v8plusa' options gives 4% better performance.

* Compiling on Linux-x86 using `gcc' without frame pointers
(`-fomit-frame-pointer' or `-fomit-frame-pointer -ffixed-ebp')
makes *Note `mysqld': mysqld. 1% to 4% faster.

File: manual.info, Node: postinstallation, Next: upgrading-downgrading, Prev: source-installation, Up: installing

3.18 Postinstallation Setup and Testing
=======================================

* Menu:

* unix-postinstallation:: Unix Postinstallation Procedures
* default-privileges:: Securing the Initial MySQL Accounts

After installing MySQL, there are some issues that you should address.
For example, on Unix, you should initialize the data directory and
create the MySQL grant tables. On all platforms, an important security
concern is that the initial accounts in the grant tables have no
passwords. You should assign passwords to prevent unauthorized access
to the MySQL server. Optionally, you can create time zone tables to
enable recognition of named time zones.

The following sections include postinstallation procedures that are
specific to Windows systems and to Unix systems. Another section, *Note
starting-server::, applies to all platforms; it describes what to do if
you have trouble getting the server to start. *Note
default-privileges::, also applies to all platforms. You should follow
its instructions to make sure that you have properly protected your
MySQL accounts by assigning passwords to them.

When you are ready to create additional user accounts, you can find
information on the MySQL access control system and account management
in *Note privilege-system::, and *Note user-account-management::.

File: manual.info, Node: unix-postinstallation, Next: default-privileges, Prev: postinstallation, Up: postinstallation

3.18.1 Unix Postinstallation Procedures
---------------------------------------

* Menu:

* mysql-install-db-problems:: Problems Running `mysql_install_db'
* automatic-start:: Starting and Stopping MySQL Automatically
* starting-server:: Starting and Troubleshooting the MySQL Server

After installing MySQL on Unix, you must initialize the grant tables,
start the server, and make sure that the server works satisfactorily.
You may also wish to arrange for the server to be started and stopped
automatically when your system starts and stops. You should also assign
passwords to the accounts in the grant tables.

On Unix, the grant tables are set up by the *Note `mysql_install_db':
mysql-install-db. program. For some installation methods, this program
is run for you automatically if an existing database cannot be found.

* If you install MySQL on Linux using RPM distributions, the server
RPM runs *Note `mysql_install_db': mysql-install-db.

* If you install MySQL on Mac OS X using a PKG distribution, the
installer runs *Note `mysql_install_db': mysql-install-db.

For other platforms and installation types, including generic binary
and source installs, you will need to run *Note `mysql_install_db':
mysql-install-db. yourself.

The following procedure describes how to initialize the grant tables
(if that has not previously been done) and start the server. It also
suggests some commands that you can use to test whether the server is
accessible and working properly. For information about starting and
stopping the server automatically, see *Note automatic-start::.

After you complete the procedure and have the server running, you
should assign passwords to the accounts created by *Note
`mysql_install_db': mysql-install-db. and perhaps tighten access to
test databases. For instructions, see *Note default-privileges::.

In the examples shown here, the server runs under the user ID of the
`mysql' login account. This assumes that such an account exists. Either
create the account if it does not exist, or substitute the name of a
different existing login account that you plan to use for running the
server.

1. Change location into the top-level directory of your MySQL
installation, represented here by BASEDIR:

shell> cd BASEDIR

BASEDIR is the installation directory for your MySQL instance. It
is likely to be something like `/usr/local/mysql' or `/usr/local'.
The following steps assume that you have changed location to this
directory.

You will find several files and subdirectories in the BASEDIR
directory. The most important for installation purposes are the
`bin' and `scripts' subdirectories:

* The `bin' directory contains client programs and the server.
You should add the full path name of this directory to your
`PATH' environment variable so that your shell finds the MySQL
programs properly. See *Note environment-variables::.

For some distribution types, *Note `mysqld': mysqld. is in
the `libexec' directory.

* The `scripts' directory contains the *Note
`mysql_install_db': mysql-install-db. script used to
initialize the `mysql' database containing the grant tables
that store the server access permissions.

For some distribution types, *Note `mysql_install_db':
mysql-install-db. is in the `bin' directory.

2. If necessary, ensure that the distribution contents are accessible
to `mysql'. If you unpacked the distribution as `mysql', no
further action is required. If you unpacked the distribution as
`root', its contents will be owned by `root'. Change its ownership
to `mysql' by executing the following commands as `root' in the
installation directory:

shell> chown -R mysql .
shell> chgrp -R mysql .

The first command changes the owner attribute of the files to the
`mysql' user. The second changes the group attribute to the
`mysql' group.

3. If necessary, run the *Note `mysql_install_db': mysql-install-db.
program to set up the initial MySQL grant tables containing the
privileges that determine how users are permitted to connect to
the server. You will need to do this if you used a distribution
type for which the installation procedure does not run the program
for you.

Typically, *Note `mysql_install_db': mysql-install-db. needs to be
run only the first time you install MySQL, so you can skip this
step if you are upgrading an existing installation, However, *Note
`mysql_install_db': mysql-install-db. does not overwrite any
existing privilege tables, so it should be safe to run in any
circumstances.

The exact location of *Note `mysql_install_db': mysql-install-db.
will depends on the layout for your given installation. To
initialize the grant tables, use one of the following commands,
depending on whether *Note `mysql_install_db': mysql-install-db.
is located in the `bin' or `scripts' directory:

shell> bin/mysql_install_db --user=mysql
shell> scripts/mysql_install_db --user=mysql

It might be necessary to specify other options such as `--basedir'
or `--datadir' if *Note `mysql_install_db': mysql-install-db. does
not identify the correct locations for the installation directory
or data directory. For example:

shell> bin/mysql_install_db --user=mysql \
--basedir=/opt/mysql/mysql \
--datadir=/opt/mysql/mysql/data

The *Note `mysql_install_db': mysql-install-db. script creates the
server's data directory with `mysql' as the owner. Under the data
directory, it creates directories for the `mysql' database that
holds the grant tables and the `test' database that you can use to
test MySQL. The script also creates privilege table entries for
`root' and anonymous-user accounts. The accounts have no passwords
initially. *Note default-privileges::, describes the initial
privileges. Briefly, these privileges permit the MySQL `root' user
to do anything, and permit anybody to create or use databases with
a name of `test' or starting with `test_'.

It is important to make sure that the database directories and
files are owned by the `mysql' login account so that the server
has read and write access to them when you run it later. To ensure
this, the `--user' option should be used as shown if you run *Note
`mysql_install_db': mysql-install-db. as `root'. Otherwise, you
should execute the script while logged in as `mysql', in which
case you can omit the `--user' option from the command.

*Note `mysql_install_db': mysql-install-db. creates several tables
in the `mysql' database, including `user', `db', `host',
`tables_priv', `columns_priv', `func', and others. See *Note
privilege-system::, for a complete listing and description of
these tables.

If you do not want to have the `test' database, you can remove it
after starting the server, using the instructions in *Note
default-privileges::.

If you have trouble with *Note `mysql_install_db':
mysql-install-db. at this point, see *Note
mysql-install-db-problems::.

4. Most of the MySQL installation can be owned by `root' if you like.
The exception is that the data directory must be owned by `mysql'.
To accomplish this, run the following commands as `root' in the
installation directory. For some distribution types, the data
directory might be named `var' rather than `data'; adjust the
second command accordingly.

shell> chown -R root .
shell> chown -R mysql data

5. If the plugin directory (the directory named by the `plugin_dir'
system variable) is writable by the server, it may be possible for
a user to write executable code to a file in the directory using
*Note `SELECT ... INTO DUMPFILE': select. This can be prevented by
making `plugin_dir' read only to the server or by setting
`--secure-file-priv' to a directory where *Note `SELECT': select.
writes can be made safely.

6. If you installed MySQL using a source distribution, you may want
to optionally copy one of the provided configuration files from
the `support-files' directory into your `/etc' directory. There are
different sample configuration files for different use cases,
server types, and CPU and RAM configurations. If you want to use
one of these standard files, you should copy it to `/etc/my.cnf',
or `/etc/mysql/my.cnf' and edit and check the configuration before
starting your MySQL server for the first time.

If you do not copy one of the standard configuration files, the
MySQL server will be started with the default settings.

If you want MySQL to start automatically when you boot your
machine, you can copy `support-files/mysql.server' to the location
where your system has its startup files. More information can be
found in the `mysql.server' script itself, and in *Note
automatic-start::.

7. Start the MySQL server:

shell> bin/mysqld_safe --user=mysql &

It is important that the MySQL server be run using an unprivileged
(non-`root') login account. To ensure this, the `--user' option
should be used as shown if you run *Note `mysqld_safe':
mysqld-safe. as system `root'. Otherwise, you should execute the
script while logged in to the system as `mysql', in which case you
can omit the `--user' option from the command.

Further instructions for running MySQL as an unprivileged user are
given in *Note changing-mysql-user::.

If the command fails immediately and prints `mysqld ended', you
can find some information in the `HOST_NAME.err' file in the data
directory.

If you neglected to create the grant tables by running *Note
`mysql_install_db': mysql-install-db. before proceeding to this
step, the following message appears in the error log file when you
start the server:

mysqld: Can't find file: 'host.frm'

This error also occurs if you run *Note `mysql_install_db':
mysql-install-db. as `root' without the `--user' option. Remove
the `data' directory and run *Note `mysql_install_db':
mysql-install-db. with the `--user' option as described previously.

If you have other problems starting the server, see *Note
starting-server::. For more information about *Note `mysqld_safe':
mysqld-safe, see *Note mysqld-safe::.

8. Use *Note `mysqladmin': mysqladmin. to verify that the server is
running. The following commands provide simple tests to check
whether the server is up and responding to connections:

shell> bin/mysqladmin version
shell> bin/mysqladmin variables

The output from *Note `mysqladmin version': mysqladmin. varies
slightly depending on your platform and version of MySQL, but
should be similar to that shown here:

shell> bin/mysqladmin version
mysqladmin Ver 14.12 Distrib 5.0.93, for pc-linux-gnu on i686
...

Server version 5.0.93
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/lib/mysql/mysql.sock
Uptime: 14 days 5 hours 5 min 21 sec

Threads: 1 Questions: 366 Slow queries: 0
Opens: 0 Flush tables: 1 Open tables: 19
Queries per second avg: 0.000

To see what else you can do with *Note `mysqladmin': mysqladmin,
invoke it with the `--help' option.

9. Verify that you can shut down the server:

shell> bin/mysqladmin -u root shutdown

10. Verify that you can start the server again. Do this by using *Note
`mysqld_safe': mysqld-safe. or by invoking *Note `mysqld': mysqld.
directly. For example:

shell> bin/mysqld_safe --user=mysql --log &

If *Note `mysqld_safe': mysqld-safe. fails, see *Note
starting-server::.

11. Run some simple tests to verify that you can retrieve information
from the server. The output should be similar to what is shown
here:

shell> bin/mysql -e "SELECT Host,Db,User FROM db" mysql
+------+--------+------+
| host | db | user |
+------+--------+------+
| % | test | |
| % | test_% | |
+------+--------+------+

12. There is a benchmark suite in the `sql-bench' directory (under the
MySQL installation directory) that you can use to compare how MySQL
performs on different platforms. The benchmark suite is written in
Perl. It requires the Perl DBI module that provides a
database-independent interface to the various databases, and some
other additional Perl modules:

DBI
DBD::mysql
Data::Dumper
Data::ShowTable

These modules can be obtained from CPAN (`http://www.cpan.org/').
See also *Note perl-installation::.

The `sql-bench/Results' directory contains the results from many
runs against different databases and platforms. To run all tests,
execute these commands:

shell> cd sql-bench
shell> perl run-all-tests

If you do not have the `sql-bench' directory, you probably
installed MySQL using RPM files other than the source RPM. (The
source RPM includes the `sql-bench' benchmark directory.) In this
case, you must first install the benchmark suite before you can
use it. There are separate benchmark RPM files named
`mysql-bench-VERSION.i386.rpm' that contain benchmark code and
data.

If you have a source distribution, there are also tests in its
`tests' subdirectory that you can run. For example, to run
`auto_increment.tst', execute this command from the top-level
directory of your source distribution:

shell> mysql -vvf test < ./tests/auto_increment.tst

The expected result of the test can be found in the
`./tests/auto_increment.res' file.

13. At this point, you should have the server running. However, none
of the initial MySQL accounts have a password, and the server
permits permissive access to test databases. To tighten security,
follow the instructions in *Note default-privileges::.

The MySQL 5.0 installation procedure creates time zone tables in the
`mysql' database but does not populate them. To do so, use the
instructions in *Note time-zone-support::.

You can set up new accounts using the `bin/mysql_setpermission' script
if you install the `DBI' and `DBD::mysql' Perl modules. See *Note
mysql-setpermission::. For Perl module installation instructions, see
*Note perl-support::.

If you would like to use *Note `mysqlaccess': mysqlaccess. and have the
MySQL distribution in some nonstandard location, you must change the
location where *Note `mysqlaccess': mysqlaccess. expects to find the
*Note `mysql': mysql. client. Edit the `bin/mysqlaccess' script at
approximately line 18. Search for a line that looks like this:

$MYSQL = '/usr/local/bin/mysql'; # path to mysql executable

Change the path to reflect the location where *Note `mysql': mysql.
actually is stored on your system. If you do not do this, a `Broken
pipe' error will occur when you run *Note `mysqlaccess': mysqlaccess.

File: manual.info, Node: mysql-install-db-problems, Next: automatic-start, Prev: unix-postinstallation, Up: unix-postinstallation

3.18.1.1 Problems Running `mysql_install_db'
............................................

The purpose of the *Note `mysql_install_db': mysql-install-db. script is
to generate new MySQL privilege tables. It does not overwrite existing
MySQL privilege tables, and it does not affect any other data.

If you want to re-create your privilege tables, first stop the *Note
`mysqld': mysqld. server if it is running. Then rename the `mysql'
directory under the data directory to save it, and then run *Note
`mysql_install_db': mysql-install-db. Suppose that your current
directory is the MySQL installation directory and that *Note
`mysql_install_db': mysql-install-db. is located in the `bin' directory
and the data directory is named `data'. To rename the `mysql' database
and re-run *Note `mysql_install_db': mysql-install-db, use these
commands.

shell> mv data/mysql data/mysql.old
shell> bin/mysql_install_db --user=mysql

When you run *Note `mysql_install_db': mysql-install-db, you might
encounter the following problems:

* **Note `mysql_install_db': mysql-install-db. fails to install the
grant tables*

You may find that *Note `mysql_install_db': mysql-install-db. fails
to install the grant tables and terminates after displaying the
following messages:

Starting mysqld daemon with databases from XXXXXX
mysqld ended

In this case, you should examine the error log file very
carefully. The log should be located in the directory `XXXXXX'
named by the error message and should indicate why *Note `mysqld':
mysqld. did not start. If you do not understand what happened,
include the log when you post a bug report. See *Note
bug-reports::.

* *There is a *Note `mysqld': mysqld. process running*

This indicates that the server is running, in which case the grant
tables have probably been created already. If so, there is no need
to run *Note `mysql_install_db': mysql-install-db. at all because
it needs to be run only once (when you install MySQL the first
time).

* *Installing a second *Note `mysqld': mysqld. server does not work
when one server is running*

This can happen when you have an existing MySQL installation, but
want to put a new installation in a different location. For
example, you might have a production installation, but you want to
create a second installation for testing purposes. Generally the
problem that occurs when you try to run a second server is that it
tries to use a network interface that is in use by the first
server. In this case, you should see one of the following error
messages:

Can't start server: Bind on TCP/IP port:
Address already in use
Can't start server: Bind on unix socket...

For instructions on setting up multiple servers, see *Note
multiple-servers::.

* *You do not have write access to the `/tmp' directory*

If you do not have write access to create temporary files or a
Unix socket file in the default location (the `/tmp' directory),
an error occurs when you run *Note `mysql_install_db':
mysql-install-db. or the *Note `mysqld': mysqld. server.

You can specify different locations for the temporary directory
and Unix socket file by executing these commands prior to starting
*Note `mysql_install_db': mysql-install-db. or *Note `mysqld':
mysqld, where SOME_TMP_DIR is the full path name to some directory
for which you have write permission:

shell> TMPDIR=/SOME_TMP_DIR/
shell> MYSQL_UNIX_PORT=/SOME_TMP_DIR/mysql.sock
shell> export TMPDIR MYSQL_UNIX_PORT

Then you should be able to run *Note `mysql_install_db':
mysql-install-db. and start the server with these commands:

shell> bin/mysql_install_db --user=mysql
shell> bin/mysqld_safe --user=mysql &

If *Note `mysql_install_db': mysql-install-db. is located in the
`scripts' directory, modify the first command to
`scripts/mysql_install_db'.

See *Note problems-with-mysql-sock::, and *Note
environment-variables::.

There are some alternatives to running the *Note `mysql_install_db':
mysql-install-db. script provided in the MySQL distribution:

* If you want the initial privileges to be different from the
standard defaults, you can modify *Note `mysql_install_db':
mysql-install-db. before you run it. However, it is preferable to
use *Note `GRANT': grant. and *Note `REVOKE': revoke. to change the
privileges _after_ the grant tables have been set up. In other
words, you can run *Note `mysql_install_db': mysql-install-db, and
then use `mysql -u root mysql' to connect to the server as the
MySQL `root' user so that you can issue the necessary *Note
`GRANT': grant. and *Note `REVOKE': revoke. statements.

If you want to install MySQL on several machines with the same
privileges, you can put the *Note `GRANT': grant. and *Note
`REVOKE': revoke. statements in a file and execute the file as a
script using `mysql' after running *Note `mysql_install_db':
mysql-install-db. For example:

shell> bin/mysql_install_db --user=mysql
shell> bin/mysql -u root < your_script_file

By doing this, you can avoid having to issue the statements
manually on each machine.

* It is possible to re-create the grant tables completely after they
have previously been created. You might want to do this if you are
just learning how to use *Note `GRANT': grant. and *Note `REVOKE':
revoke. and have made so many modifications after running *Note
`mysql_install_db': mysql-install-db. that you want to wipe out
the tables and start over.

To re-create the grant tables, remove all the `.frm', `.MYI', and
`.MYD' files in the `mysql' database directory. Then run the *Note
`mysql_install_db': mysql-install-db. script again.

* You can start *Note `mysqld': mysqld. manually using the
`--skip-grant-tables' option and add the privilege information
yourself using *Note `mysql': mysql.:

shell> bin/mysqld_safe --user=mysql --skip-grant-tables &
shell> bin/mysql mysql

From *Note `mysql': mysql, manually execute the SQL commands
contained in *Note `mysql_install_db': mysql-install-db. Make
sure that you run *Note `mysqladmin flush-privileges': mysqladmin.
or *Note `mysqladmin reload': mysqladmin. afterward to tell the
server to reload the grant tables.

Note that by not using *Note `mysql_install_db': mysql-install-db,
you not only have to populate the grant tables manually, you also
have to create them first.

File: manual.info, Node: automatic-start, Next: starting-server, Prev: mysql-install-db-problems, Up: unix-postinstallation

3.18.1.2 Starting and Stopping MySQL Automatically
..................................................

Generally, you start the *Note `mysqld': mysqld. server in one of these
ways:

* Invoke *Note `mysqld': mysqld. directly. This works on any
platform.

* Run the MySQL server as a Windows service. The service can be set
to start the server automatically when Windows starts, or as a
manual service that you start on request. For instructions, see
*Note windows-start-service::.

* Invoke *Note `mysqld_safe': mysqld-safe, which tries to determine
the proper options for *Note `mysqld': mysqld. and then runs it
with those options. This script is used on Unix and Unix-like
systems. See *Note mysqld-safe::.

* Invoke *Note `mysql.server': mysql-server. This script is used
primarily at system startup and shutdown on systems that use
System V-style run directories (that is, `/etc/init.d' and
run-level specific directories), where it usually is installed
under the name `mysql'. The *Note `mysql.server': mysql-server.
script starts the server by invoking *Note `mysqld_safe':
mysqld-safe. See *Note mysql-server::.

* On Mac OS X, install a separate MySQL Startup Item package to
enable the automatic startup of MySQL on system startup. The
Startup Item starts the server by invoking *Note `mysql.server':
mysql-server. See *Note macosx-installation::, for details.

The *Note `mysqld_safe': mysqld-safe. and *Note `mysql.server':
mysql-server. scripts and the Mac OS X Startup Item can be used to
start the server manually, or automatically at system startup time.
*Note `mysql.server': mysql-server. and the Startup Item also can be
used to stop the server.

To start or stop the server manually using the *Note `mysql.server':
mysql-server. script, invoke it with `start' or `stop' arguments:

shell> mysql.server start
shell> mysql.server stop

Before *Note `mysql.server': mysql-server. starts the server, it
changes location to the MySQL installation directory, and then invokes
*Note `mysqld_safe': mysqld-safe. If you want the server to run as some
specific user, add an appropriate `user' option to the `[mysqld]' group
of the `/etc/my.cnf' option file, as shown later in this section. (It
is possible that you will need to edit *Note `mysql.server':
mysql-server. if you've installed a binary distribution of MySQL in a
nonstandard location. Modify it to change location into the proper
directory before it runs *Note `mysqld_safe': mysqld-safe. If you do
this, your modified version of *Note `mysql.server': mysql-server. may
be overwritten if you upgrade MySQL in the future, so you should make a
copy of your edited version that you can reinstall.)

*Note `mysql.server stop': mysql-server. stops the server by sending a
signal to it. You can also stop the server manually by executing *Note
`mysqladmin shutdown': mysqladmin.

To start and stop MySQL automatically on your server, you need to add
start and stop commands to the appropriate places in your `/etc/rc*'
files.

If you use the Linux server RPM package (`MySQL-server-VERSION.rpm'),
the *Note `mysql.server': mysql-server. script is installed in the
`/etc/init.d' directory with the name `mysql'. You need not install it
manually. See *Note linux-installation-rpm::, for more information on
the Linux RPM packages.

Some vendors provide RPM packages that install a startup script under a
different name such as *Note `mysqld': mysqld.

If you install MySQL from a source distribution or using a binary
distribution format that does not install *Note `mysql.server':
mysql-server. automatically, you can install it manually. The script
can be found in the `support-files' directory under the MySQL
installation directory or in a MySQL source tree.

To install *Note `mysql.server': mysql-server. manually, copy it to the
`/etc/init.d' directory with the name *Note `mysql': mysql, and then
make it executable. Do this by changing location into the appropriate
directory where *Note `mysql.server': mysql-server. is located and
executing these commands:

shell> cp mysql.server /etc/init.d/mysql
shell> chmod +x /etc/init.d/mysql

*Note*:

Older Red Hat systems use the `/etc/rc.d/init.d' directory rather than
`/etc/init.d'. Adjust the preceding commands accordingly.
Alternatively, first create `/etc/init.d' as a symbolic link that
points to `/etc/rc.d/init.d':

shell> cd /etc
shell> ln -s rc.d/init.d .

After installing the script, the commands needed to activate it to run
at system startup depend on your operating system. On Linux, you can
use `chkconfig':

shell> chkconfig --add mysql

On some Linux systems, the following command also seems to be necessary
to fully enable the *Note `mysql': mysql. script:

shell> chkconfig --level 345 mysql on

On FreeBSD, startup scripts generally should go in
`/usr/local/etc/rc.d/'. The `rc(8)' manual page states that scripts in
this directory are executed only if their basename matches the `*.sh'
shell file name pattern. Any other files or directories present within
the directory are silently ignored. In other words, on FreeBSD, you
should install the `mysql.server' script as
`/usr/local/etc/rc.d/mysql.server.sh' to enable automatic startup.

As an alternative to the preceding setup, some operating systems also
use `/etc/rc.local' or `/etc/init.d/boot.local' to start additional
services on startup. To start up MySQL using this method, you could
append a command like the one following to the appropriate startup file:

/bin/sh -c 'cd /usr/local/mysql; ./bin/mysqld_safe --user=mysql &'

For other systems, consult your operating system documentation to see
how to install startup scripts.

You can add options for *Note `mysql.server': mysql-server. in a global
`/etc/my.cnf' file. A typical `/etc/my.cnf' file might look like this:

[mysqld]
datadir=/usr/local/mysql/var
socket=/var/tmp/mysql.sock
port=3306
user=mysql

[mysql.server]
basedir=/usr/local/mysql

The *Note `mysql.server': mysql-server. script supports the following
options: `basedir', `datadir', and `pid-file'. If specified, they
_must_ be placed in an option file, not on the command line. *Note
`mysql.server': mysql-server. supports only `start' and `stop' as
command-line arguments.

The following table shows which option groups the server and each
startup script read from option files.

*MySQL Startup scripts and supported server option groups*

Script Option Groups
*Note `[mysqld]', `[server]', `[mysqld-MAJOR_VERSION]'
`mysqld':
mysqld.
*Note `[mysqld]', `[server]', `[mysqld_safe]'
`mysqld_safe':
mysqld-safe.
*Note `[mysqld]', `[mysql.server]', `[server]'
`mysql.server':
mysql-server.

`[mysqld-MAJOR_VERSION]' means that groups with names like
`[mysqld-4.1]' and `[mysqld-5.0]' are read by servers having versions
4.1.x, 5.0.x, and so forth. This feature can be used to specify options
that can be read only by servers within a given release series.

For backward compatibility, *Note `mysql.server': mysql-server. also
reads the `[mysql_server]' group and *Note `mysqld_safe': mysqld-safe.
also reads the `[safe_mysqld]' group. However, you should update your
option files to use the `[mysql.server]' and `[mysqld_safe]' groups
instead when using MySQL 5.0.

For more information on MySQL configuration files and their structure
and contents, see *Note option-files::.

File: manual.info, Node: starting-server, Prev: automatic-start, Up: unix-postinstallation

3.18.1.3 Starting and Troubleshooting the MySQL Server
......................................................

This section provides troubleshooting suggestions for problems starting
the server on Unix. If you are using Windows, see *Note
windows-troubleshooting::.

If you have problems starting the server, here are some things to try:

* Check the error log to see why the server does not start.

* Specify any special options needed by the storage engines you are
using.

* Make sure that the server knows where to find the data directory.

* Make sure that the server can access the data directory. The
ownership and permissions of the data directory and its contents
must be set such that the server can read and modify them.

* Verify that the network interfaces the server wants to use are
available.

Some storage engines have options that control their behavior. You can
create a `my.cnf' file and specify startup options for the engines that
you plan to use. If you are going to use storage engines that support
transactional tables (`InnoDB', `BDB', *Note `NDB': mysql-cluster.), be
sure that you have them configured the way you want before starting the
server:

* If you are using `InnoDB' tables, see *Note innodb-configuration::.

* If you are using `BDB' (Berkeley DB) tables, see *Note bdb-start::.

* If you are using MySQL Cluster, see *Note
mysql-cluster-configuration::.

Storage engines will use default option values if you specify none, but
it is recommended that you review the available options and specify
explicit values for those for which the defaults are not appropriate
for your installation.

When the *Note `mysqld': mysqld. server starts, it changes location to
the data directory. This is where it expects to find databases and
where it expects to write log files. The server also writes the pid
(process ID) file in the data directory.

The data directory location is hardwired in when the server is
compiled. This is where the server looks for the data directory by
default. If the data directory is located somewhere else on your
system, the server will not work properly. You can determine what the
default path settings are by invoking *Note `mysqld': mysqld. with the
`--verbose' and `--help' options.

If the default locations do not match the MySQL installation layout on
your system, you can override them by specifying options to *Note
`mysqld': mysqld. or *Note `mysqld_safe': mysqld-safe. on the command
line or in an option file.

To specify the location of the data directory explicitly, use the
`--datadir' option. However, normally you can tell *Note `mysqld':
mysqld. the location of the base directory under which MySQL is
installed and it looks for the data directory there. You can do this
with the `--basedir' option.

To check the effect of specifying path options, invoke *Note `mysqld':
mysqld. with those options followed by the `--verbose' and `--help'
options. For example, if you change location into the directory where
*Note `mysqld': mysqld. is installed and then run the following
command, it shows the effect of starting the server with a base
directory of `/usr/local':

shell> ./mysqld --basedir=/usr/local --verbose --help

You can specify other options such as `--datadir' as well, but
`--verbose' and `--help' must be the last options.

Once you determine the path settings you want, start the server without
`--verbose' and `--help'.

If *Note `mysqld': mysqld. is currently running, you can find out what
path settings it is using by executing this command:

shell> mysqladmin variables

Or:

shell> mysqladmin -h HOST_NAME variables

HOST_NAME is the name of the MySQL server host.

If you get `Errcode 13' (which means `Permission denied') when starting
*Note `mysqld': mysqld, this means that the privileges of the data
directory or its contents do not permit server access. In this case,
you change the permissions for the involved files and directories so
that the server has the right to use them. You can also start the
server as `root', but this raises security issues and should be avoided.

On Unix, change location into the data directory and check the
ownership of the data directory and its contents to make sure the
server has access. For example, if the data directory is
`/usr/local/mysql/var', use this command:

shell> ls -la /usr/local/mysql/var

If the data directory or its files or subdirectories are not owned by
the login account that you use for running the server, change their
ownership to that account. If the account is named `mysql', use these
commands:

shell> chown -R mysql /usr/local/mysql/var
shell> chgrp -R mysql /usr/local/mysql/var

If it possible that even with correct ownership, MySQL may fail to
start up if there is other security software running on your system
that manages application access to various parts of the file system. In
this case, you may need to reconfigure that software to enable *Note
`mysqld': mysqld. to access the directories it uses during normal
operation.

If the server fails to start up correctly, check the error log. Log
files are located in the data directory (typically `C:\Program
Files\MySQL\MySQL Server 5.0\data' on Windows, `/usr/local/mysql/data'
for a Unix binary distribution, and `/usr/local/var' for a Unix source
distribution). Look in the data directory for files with names of the
form `HOST_NAME.err' and `HOST_NAME.log', where HOST_NAME is the name
of your server host. Then examine the last few lines of these files. On
Unix, you can use `tail' to display them:

shell> tail HOST_NAME.err
shell> tail HOST_NAME.log

The error log should contain information that indicates why the server
could not start. For example, you might see something like this in the
log:

000729 14:50:10 bdb: Recovery function for LSN 1 27595 failed
000729 14:50:10 bdb: warning: ./test/t1.db: No such file or directory
000729 14:50:10 Can't init databases

This means that you did not start *Note `mysqld': mysqld. with the
`--bdb-no-recover' option and Berkeley DB found something wrong with
its own log files when it tried to recover your databases. To be able
to continue, you should move the old Berkeley DB log files from the
database directory to some other place, where you can later examine
them. The `BDB' log files are named in sequence beginning with
`log.0000000001', where the number increases over time.

If you are running *Note `mysqld': mysqld. with `BDB' table support and
*Note `mysqld': mysqld. dumps core at startup, this could be due to
problems with the `BDB' recovery log. In this case, you can try
starting *Note `mysqld': mysqld. with `--bdb-no-recover'. If that helps,
you should remove all `BDB' log files from the data directory and try
starting *Note `mysqld': mysqld. again without the `--bdb-no-recover'
option.

If either of the following errors occur, it means that some other
program (perhaps another *Note `mysqld': mysqld. server) is using the
TCP/IP port or Unix socket file that *Note `mysqld': mysqld. is trying
to use:

Can't start server: Bind on TCP/IP port: Address already in use
Can't start server: Bind on unix socket...

Use `ps' to determine whether you have another *Note `mysqld': mysqld.
server running. If so, shut down the server before starting *Note
`mysqld': mysqld. again. (If another server is running, and you really
want to run multiple servers, you can find information about how to do
so in *Note multiple-servers::.)

If no other server is running, try to execute the command `telnet
YOUR_HOST_NAME TCP_IP_PORT_NUMBER'. (The default MySQL port number is
3306.) Then press Enter a couple of times. If you do not get an error
message like `telnet: Unable to connect to remote host: Connection
refused', some other program is using the TCP/IP port that *Note
`mysqld': mysqld. is trying to use. You will need to track down what
program this is and disable it, or else tell *Note `mysqld': mysqld. to
listen to a different port with the `--port' option. In this case, you
will also need to specify the port number for client programs when
connecting to the server using TCP/IP.

Another reason the port might be inaccessible is that you have a
firewall running that blocks connections to it. If so, modify the
firewall settings to permit access to the port.

If the server starts but you cannot connect to it, you should make sure
that you have an entry in `/etc/hosts' that looks like this:

127.0.0.1 localhost

If you cannot get *Note `mysqld': mysqld. to start, you can try to make
a trace file to find the problem by using the `--debug' option. See
MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

File: manual.info, Node: default-privileges, Prev: unix-postinstallation, Up: postinstallation

3.18.2 Securing the Initial MySQL Accounts
------------------------------------------

Part of the MySQL installation process is to set up the `mysql'
database that contains the grant tables:

* Windows distributions contain preinitialized grant tables.

* On Unix, the *Note `mysql_install_db': mysql-install-db. program
populates the grant tables. Some installation methods run this
program for you. Others require that you execute it manually. For
details, see *Note unix-postinstallation::.

The `mysql.user' grant table defines the initial MySQL user accounts
and their access privileges:

* Some accounts have the user name `root'. These are superuser
accounts that have all privileges and can do anything. The initial
`root' account passwords are empty, so anyone can connect to the
MySQL server as `root' _without a password_ and be granted all
privileges.

* On Windows, `root' accounts are created that permit
connections from the local host only. Connections can be
made by specifying the host name `localhost' or the IP address
`127.0.0.1'. If the user selects the `Enable root access from
remote machines' option during installation, the Windows
installer creates another `root' account that permits
connections from any host.

* On Unix, each `root' account permits connections from the
local host. Connections can be made by specifying the host
name `localhost', the IP address `127.0.0.1', or the actual
host name or IP address.

An attempt to connect to the host `127.0.0.1' normally resolves to
the `localhost' account. However, this fails if the server is run
with the `--skip-name-resolve' option, so the `127.0.0.1' account
is useful in that case.

* Some accounts are for anonymous users. These have an empty user
name. The anonymous accounts have no password, so anyone can use
them to connect to the MySQL server.

* On Windows, there is one anonymous account that permits
connections from the local host. Connections can be made by
specifying a host name of `localhost'. It has no global
privileges. (Before MySQL 5.0.36, it has all global
privileges, just like the `root' accounts.)

* On Unix, each anonymous account permits connections from the
local host. Connections can be made by specifying a host name
of `localhost' for one of the accounts, or the actual host
name or IP address for the other.

To display which accounts exist in the `mysql.user' table and check
whether their passwords are empty, use the following statement:

This output indicates that there are several `root' and anonymous-user
accounts, none of which have passwords. The output might differ on your
system, but the presence of accounts with empty passwords means that
your MySQL installation is unprotected until you do something about it:

* You should assign a password to each MySQL `root' account.

* If you want to prevent clients from connecting as anonymous users
without a password, you should either assign a password to each
anonymous account or else remove the accounts.

In addition, the `mysql.db' table contains rows that permit all
accounts to access the `test' database and other databases with names
that start with `test_'. This is true even for accounts that otherwise
have no special privileges such as the default anonymous accounts. This
is convenient for testing but inadvisable on production servers.
Administrators who want database access restricted only to accounts
that have permissions granted explicitly for that purpose should remove
these `mysql.db' table rows.

The following instructions describe how to set up passwords for the
initial MySQL accounts, first for the `root' accounts, then for the
anonymous accounts. The instructions also cover how to remove the
anonymous accounts, should you prefer not to permit anonymous access at
all, and describe how to remove permissive access to test databases.
Replace NEWPWD in the examples with the password that you want to use.
Replace HOST_NAME with the name of the server host. You can determine
this name from the output of the preceding *Note `SELECT': select.
statement. For the output shown, HOST_NAME is `myhost.example.com'.

*Note*:

For additional information about setting passwords, see *Note
assigning-passwords::. If you forget your `root' password after setting
it, see *Note resetting-permissions::.

You might want to defer setting the passwords until later, to avoid the
need to specify them while you perform additional setup or testing.
However, be sure to set them before using your installation for
production purposes.

To set up additional accounts, see *Note adding-users::.

Assigning `root' Account Passwords

The `root' account passwords can be set several ways. The following
discussion demonstrates three methods:

* Use the *Note `SET PASSWORD': set-password. statement

* Use the *Note `UPDATE': update. statement

* Use the *Note `mysqladmin': mysqladmin. command-line client program

To assign passwords using *Note `SET PASSWORD': set-password, connect
to the server as `root' and issue a *Note `SET PASSWORD': set-password.
statement for each `root' account listed in the `mysql.user' table. Be
sure to encrypt the password using the `PASSWORD()' function.

For Windows, do this:

shell> mysql -u root
mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('NEWPWD');
mysql> SET PASSWORD FOR 'root'@'127.0.0.1' = PASSWORD('NEWPWD');
mysql> SET PASSWORD FOR 'root'@'%' = PASSWORD('NEWPWD');

The last statement is unnecessary if the `mysql.user' table has no
`root' account with a host value of `%'.

For Unix, do this:

You can also use a single statement that assigns a password to all
`root' accounts by using *Note `UPDATE': update. to modify the
`mysql.user' table directly. This method works on any platform:

shell> mysql -u root
mysql> UPDATE mysql.user SET Password = PASSWORD('NEWPWD')
-> WHERE User = 'root';
mysql> FLUSH PRIVILEGES;

The *Note `FLUSH': flush. statement causes the server to reread the
grant tables. Without it, the password change remains unnoticed by the
server until you restart it.

To assign passwords to the `root' accounts using *Note `mysqladmin':
mysqladmin, execute the following commands:

shell> mysqladmin -u root password "NEWPWD"
shell> mysqladmin -u root -h HOST_NAME password "NEWPWD"

Those commands apply both to Windows and to Unix. The double quotation
marks around the password are not always necessary, but you should use
them if the password contains spaces or other characters that are
special to your command interpreter.

The *Note `mysqladmin': mysqladmin. method of setting the `root'
account passwords does not work for the `'root'@'127.0.0.1'' account.
Use the *Note `SET PASSWORD': set-password. method shown earlier.

After the `root' passwords have been set, you must supply the
appropriate password whenever you connect as `root' to the server. For
example, to shut down the server with *Note `mysqladmin': mysqladmin,
use this command:

shell> mysqladmin -u root -p shutdown
Enter password: (ENTER ROOT PASSWORD HERE)

Assigning Anonymous Account Passwords

The *Note `mysql': mysql. commands in the following instructions
include a `-p' option based on the assumption that you have set the
`root' account passwords using the preceding instructions and must
specify that password when connecting to the server.

To assign passwords to the anonymous accounts, connect to the server as
`root', then use either *Note `SET PASSWORD': set-password. or *Note
`UPDATE': update. Be sure to encrypt the password using the `PASSWORD()'
function.

To use *Note `SET PASSWORD': set-password. on Windows, do this:

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> SET PASSWORD FOR ''@'localhost' = PASSWORD('NEWPWD');

To use *Note `SET PASSWORD': set-password. on Unix, do this:

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> SET PASSWORD FOR ''@'localhost' = PASSWORD('NEWPWD');
mysql> SET PASSWORD FOR ''@'HOST_NAME' = PASSWORD('NEWPWD');

To set the anonymous-user account passwords with a single *Note
`UPDATE': update. statement, do this (on any platform):

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> UPDATE mysql.user SET Password = PASSWORD('NEWPWD')
-> WHERE User = '';
mysql> FLUSH PRIVILEGES;

The *Note `FLUSH': flush. statement causes the server to reread the
grant tables. Without it, the password change remains unnoticed by the
server until you restart it.

Removing Anonymous Accounts

If you prefer to remove any anonymous accounts rather than assigning
them passwords, do so as follows on Windows:

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> DROP USER ''@'localhost';

On Unix, remove the anonymous accounts like this:

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> DROP USER ''@'localhost';
mysql> DROP USER ''@'HOST_NAME';

Securing Test Databases

By default, the `mysql.db' table contains rows that permit access by
any user to the `test' database and other databases with names that
start with `test_'. (These rows have an empty `User' column value,
which for access-checking purposes matches any user name.) This means
that such databases can be used even by accounts that otherwise possess
no privileges. If you want to remove any-user access to test
databases, do so as follows:

shell> mysql -u root -p
Enter password: (ENTER ROOT PASSWORD HERE)
mysql> DELETE FROM mysql.db WHERE Db LIKE 'test%';
mysql> FLUSH PRIVILEGES;

The *Note `FLUSH': flush. statement causes the server to reread the
grant tables. Without it, the privilege change remains unnoticed by the
server until you restart it.

With the preceding change, only users who have global database
privileges or privileges granted explicitly for the `test' database can
use it. However, if you do not want the database to exist at all, drop
it:

mysql> DROP DATABASE test;

*Note*:

On Windows, you can also perform the process described in this section
using the Configuration Wizard (see *Note
mysql-config-wizard-security::). On other platforms, the MySQL
distribution includes *Note `mysql_secure_installation':
mysql-secure-installation, a command-line utility that automates much
of the process of securing a MySQL installation.

File: manual.info, Node: upgrading-downgrading, Next: operating-system-specific-notes, Prev: postinstallation, Up: installing

3.19 Upgrading or Downgrading MySQL
===================================

* Menu:

* upgrading:: Upgrading MySQL
* downgrading:: Downgrading MySQL
* checking-table-incompatibilities:: Checking Whether Tables or Indexes Must Be Rebuilt
* rebuilding-tables:: Rebuilding or Repairing Tables or Indexes
* copying-databases:: Copying MySQL Databases to Another Machine

File: manual.info, Node: upgrading, Next: downgrading, Prev: upgrading-downgrading, Up: upgrading-downgrading

3.19.1 Upgrading MySQL
----------------------

* Menu:

* upgrading-from-early-5-0:: Upgrading from MySQL 5.0 to 5.0.10 or Higher
* upgrading-from-previous-series:: Upgrading from MySQL 4.1 to 5.0

As a general rule, to upgrade from one release series to another, you
should go to the next series rather than skipping a series. To upgrade
from a release series previous to MySQL 4.1, upgrade to each successive
release series in turn until you have reached MySQL 4.1, and then
proceed with the upgrade to MySQL 5.0. For example, if you currently are
running MySQL 4.0 and wish to upgrade to a newer series, upgrade to
MySQL 4.1 first before upgrading to 5.0, and so forth. For information
on upgrading to MySQL 4.1 or earlier releases, see the `MySQL 3.23,
4.0, 4.1 Reference Manual'.

To upgrade from MySQL 4.1 to 5.0, use the items in the following
checklist as a guide:

* Before any upgrade, back up your databases, including the `mysql'
database that contains the grant tables. See *Note
backup-methods::.

* Read _all_ the notes in *Note upgrading-from-previous-series::.
These notes enable you to identify upgrade issues that apply to
your current MySQL installation. Some incompatibilities discussed
in that section require your attention _before_ upgrading. Others
should be dealt with _after_ upgrading.

* Read *Note news:: as well, which provides information about
features that are new in MySQL 5.0 or differ from those found in
MySQL 4.1.

* After upgrading to a new version of MySQL, run *Note
`mysql_upgrade': mysql-upgrade. (see *Note mysql-upgrade::). This
program checks your tables, and attempts to repair them if
necessary. It also updates your grant tables to make sure that
they have the current structure so that you can take advantage of
any new capabilities. (Some releases of MySQL introduce changes to
the structure of the grant tables to add new privileges or
features.)

*Note `mysql_upgrade': mysql-upgrade. does not upgrade the contents
of the help tables. For upgrade instructions, see *Note
server-side-help-support::.

* If you run MySQL Server on Windows, see *Note windows-upgrading::.

* If you use replication, see *Note replication-upgrade::, for
information on upgrading your replication setup.

* If you upgrade an installation originally produced by installing
multiple RPM packages, it is best to upgrade all the packages, not
just some. For example, if you previously installed the server and
client RPMs, do not upgrade just the server RPM.

* MySQL 5.0.27 is the last version in MySQL 5.0 for which MySQL-Max
binary distributions are provided, except for RPM distributions.
For RPMs, MySQL 5.0.37 is the last release. After these versions,
the features previously included in the `mysqld-max' server are
included in *Note `mysqld': mysqld.

If you previously installed a MySQL-Max distribution that includes
a server named `mysqld-max', and then upgrade later to a non-Max
version of MySQL, *Note `mysqld_safe': mysqld-safe. still attempts
to run the old `mysqld-max' server. If you perform such an
upgrade, you should remove the old `mysqld-max' server manually to
ensure that *Note `mysqld_safe': mysqld-safe. runs the new *Note
`mysqld': mysqld. server.

You can always move the MySQL format files and data files between
different versions on systems with the same architecture as long as you
stay within versions for the same release series of MySQL.

If you are cautious about using new versions, you can always rename
your old *Note `mysqld': mysqld. before installing a newer one. For
example, if you are using a version of MySQL 4.1 and want to upgrade to
5.0, rename your current server from *Note `mysqld': mysqld. to
`mysqld-4.1'. If your new *Note `mysqld': mysqld. then does something
unexpected, you can simply shut it down and restart with your old *Note
`mysqld': mysqld.

If, after an upgrade, you experience problems with compiled client
programs, such as `Commands out of sync' or unexpected core dumps, you
probably have used old header or library files when compiling your
programs. In this case, you should check the date for your `mysql.h'
file and `libmysqlclient.a' library to verify that they are from the
new MySQL distribution. If not, recompile your programs with the new
headers and libraries. Recompilation might also be necessary for
programs compiled against the shared client library if the library
major version number has changed (for example from
`libmysqlclient.so.15' to `libmysqlclient.so.16'.

If problems occur, such as that the new *Note `mysqld': mysqld. server
does not start or that you cannot connect without a password, verify
that you do not have an old `my.cnf' file from your previous
installation. You can check this with the `--print-defaults' option
(for example, *Note `mysqld --print-defaults': mysqld.). If this
command displays anything other than the program name, you have an
active `my.cnf' file that affects server or client operation.

If your MySQL installation contains a large amount of data that might
take a long time to convert after an in-place upgrade, you might find
it useful to create a `dummy' database instance for assessing what
conversions might be needed and the work involved to perform them. Make
a copy of your MySQL instance that contains a full copy of the `mysql'
database, plus all other databases without data. Run your upgrade
procedure on this dummy instance to see what actions might be needed so
that you can better evaluate the work involved when performing actual
data conversion on your original database instance.

It is a good idea to rebuild and reinstall the Perl `DBD::mysql' module
whenever you install a new release of MySQL. The same applies to other
MySQL interfaces as well, such as PHP `mysql' extensions and the Python
`MySQLdb' module.

File: manual.info, Node: upgrading-from-early-5-0, Next: upgrading-from-previous-series, Prev: upgrading, Up: upgrading

3.19.1.1 Upgrading from MySQL 5.0 to 5.0.10 or Higher
.....................................................

*After upgrading a 5.0 installation to 5.0.10 or higher*, it is
_necessary_ to upgrade your grant tables. Otherwise, creating stored
procedures and functions might not work. The procedure for doing this
is described in *Note mysql-upgrade::.

File: manual.info, Node: upgrading-from-previous-series, Prev: upgrading-from-early-5-0, Up: upgrading

3.19.1.2 Upgrading from MySQL 4.1 to 5.0
........................................

*Note*:

It is good practice to back up your data before installing any new
version of software. Although MySQL works very hard to ensure a high
level of quality, you should protect your data by making a backup.

To upgrade to 5.0 from any previous version, MySQL recommends that you
dump your tables with *Note `mysqldump': mysqldump. before upgrading
and reload the dump file after upgrading.

In general, you should do the following when upgrading from MySQL 4.1
to 5.0:

* Read _all_ the items in the following sections to see whether any
of them might affect your applications:

* *Note upgrading::, has general update information.

* The items in the change lists found later in this section
enable you to identify upgrade issues that apply to your
current MySQL installation.

* The MySQL 5.0 change history describes significant new
features you can use in 5.0 or that differ from those found
in MySQL 4.1. Some of these changes may result in
incompatibilities. See *Note news-5-0-x::.

Note particularly any changes that are marked *Known issue* or
*Incompatible change*. These incompatibilities with earlier
versions of MySQL may require your attention _before you upgrade_.
Our aim is to avoid these changes, but occasionally they are
necessary to correct problems that would be worse than an
incompatibility between releases. If any upgrade issue applicable
to your installation involves an incompatibility that requires
special handling, follow the instructions given in the
incompatibility description. Often this will involve dumping and
reloading tables, or use of a statement such as *Note `CHECK
TABLE': check-table. or *Note `REPAIR TABLE': repair-table.

For dump and reload instructions, see *Note rebuilding-tables::.
Any procedure that involves *Note `REPAIR TABLE': repair-table.
with the `USE_FRM' option _must_ be done before upgrading. Use of
this statement with a version of MySQL different from the one used
to create the table (that is, using it after upgrading) may damage
the table. See *Note repair-table::.

* Before upgrading to a new version of MySQL, *Note
checking-table-incompatibilities::, to see whether changes to
table formats or to character sets or collations were made between
your current version of MySQL and the version to which you are
upgrading. If so and these changes result in an incompatibility
between MySQL versions, you will need to upgrade the affected
tables using the instructions in *Note rebuilding-tables::.

*Note `mysql_upgrade': mysql-upgrade. does not upgrade the
contents of the help tables. For upgrade instructions, see *Note
server-side-help-support::.

* If you run MySQL Server on Windows, see *Note windows-upgrading::.

* MySQL 5.0 adds support for stored procedures. This support
requires the `mysql.proc' table. To create this table, you should
run the *Note `mysql_upgrade': mysql-upgrade. program as described
in *Note mysql-upgrade::.

* MySQL 5.0 adds support for views. This support requires extra
privilege columns in the `mysql.user' and `mysql.db' tables. To
create these columns, you should run the *Note `mysql_upgrade':
mysql-upgrade. program as described in *Note mysql-upgrade::.

* If you use replication, see *Note replication-upgrade::, for
information on upgrading your replication setup.

Several visible behaviors have changed between MySQL 4.1 and MySQL 5.0
to make MySQL more compatible with standard SQL. These changes may
affect your applications.

The following lists describe changes that may affect applications and
that you should watch out for when upgrading from MySQL 4.1 to 5.0.

Server Changes

* *Incompatible change*: Character set changes were made in MySQL
5.0.48 that may require table indexes to be rebuilt. For details,
see *Note checking-table-incompatibilities::.

* *Incompatible change*: The indexing order for end-space in *Note
`TEXT': blob. columns for `InnoDB' and `MyISAM' tables has
changed. Starting from 5.0.3, *Note `TEXT': blob. indexes are
compared as space-padded at the end (just as MySQL sorts *Note
`CHAR': char, *Note `VARCHAR': char. and *Note `TEXT': blob.
fields). If you have an index on a *Note `TEXT': blob. column, you
should run *Note `CHECK TABLE': check-table. on it. If the check
reports errors, rebuild the indexes: Dump and reload the table if
it is an `InnoDB' table, or run *Note `OPTIMIZE TABLE':
optimize-table. or *Note `REPAIR TABLE': repair-table. if it is a
`MyISAM' table.

* *Incompatible change*. For *Note `BINARY': binary-varbinary.
columns, the pad value and how it is handled has changed as of
MySQL 5.0.15. The pad value for inserts now is `0x00' rather than
space, and there is no stripping of the pad value for retrievals.
For details, see *Note binary-varbinary::.

* *Incompatible change*. As of MySQL 5.0.3, trailing spaces no
longer are removed from values stored in *Note `VARCHAR': char. and
*Note `VARBINARY': binary-varbinary. columns. The maximum lengths
for *Note `VARCHAR': char. and *Note `VARBINARY':
binary-varbinary. columns in MySQL 5.0.3 and later are 65,535
characters and 65,535 bytes, respectively.

When a binary upgrade (filesystem-level copy of data files) to
MySQL 5.0 is performed for a table with a *Note `VARBINARY':
binary-varbinary. column, the column is space-padded to the full
permissible width of the column. This causes values in *Note
`VARBINARY': binary-varbinary. columns that do not occupy the full
width of the column to include extra trailing spaces after the
upgrade, which means that the data in the column is different.

In addition, new rows inserted into a table upgraded in this way
will be space padded to the full width of the column.

This issue can be resolved as follows:

1. For each table containing *Note `VARBINARY':
binary-varbinary. columns, execute the following statement,
where TBL_NAME is the name of the table and ENGINE_NAME is the
name of the storage engine currently used by TBL_NAME:

ALTER TABLE TBL_NAME ENGINE=ENGINE_NAME;

In other words, if the table named `mytable' uses the
`MyISAM' storage engine, then you would use this statement:

ALTER TABLE mytable ENGINE=MYISAM;

This rebuilds the table so that it uses the 5.0 *Note
`VARBINARY': binary-varbinary. format.

2. Then you must remove all trailing spaces from any *Note
`VARBINARY': binary-varbinary. column values. For each *Note
`VARBINARY': binary-varbinary. column VARBINARY_COLUMN,
execute the following statement, where TBL_NAME is the name
of the table containing the *Note `VARBINARY':
binary-varbinary. column:

UPDATE TBL_NAME SET VARBINARY_COLUMN = RTRIM(VARBINARY_COLUMN);

This is necessary and safe because trailing spaces are
stripped before 5.0.3, meaning that any trailing spaces are
erroneous.

This problem does not occur (and thus these two steps are not
required) for tables upgraded using the recommended procedure of
dumping tables prior to the upgrade and reloading them afterward.

*Note*:

If you create a table with new *Note `VARCHAR': char. or *Note
`VARBINARY': binary-varbinary. columns in MySQL 5.0.3 or later,
the table will not be usable if you downgrade to a version older
than 5.0.3. Dump the table with *Note `mysqldump': mysqldump.
before downgrading and reload it after downgrading.

* *Incompatible change*: The implementation of *Note `DECIMAL':
numeric-types. was changed in MySQL 5.0.3. You should make your
applications aware of this change. For information about this
change, and about possible incompatibilities with old
applications, see *Note precision-math::, in particular, *Note
precision-math-decimal-changes::.

*Note `DECIMAL': numeric-types. columns are stored in a more
efficient format. To convert a table to use the new *Note
`DECIMAL': numeric-types. type, you should do an *Note `ALTER
TABLE': alter-table. on it. (The *Note `ALTER TABLE': alter-table.
also will change the table's *Note `VARCHAR': char. columns to use
the new *Note `VARCHAR': char. data type properties, described in
a separate item.)

A consequence of the change in handling of the *Note `DECIMAL':
numeric-types. and *Note `NUMERIC': numeric-types. fixed-point data
types is that the server is more strict to follow standard SQL.
For example, a data type of `DECIMAL(3,1)' stores a maximum value
of 99.9. Before MySQL 5.0.3, the server permitted larger numbers
to be stored. That is, it stored a value such as 100.0 as 100.0.
As of MySQL 5.0.3, the server clips 100.0 to the maximum
permissible value of 99.9. If you have tables that were created
before MySQL 5.0.3 and that contain floating-point data not
strictly legal for the data type, you should alter the data types
of those columns. For example:

ALTER TABLE TBL_NAME MODIFY COL_NAME DECIMAL(4,1);

The behavior used by the server for *Note `DECIMAL':
numeric-types. columns in a table depends on the version of MySQL
used to create the table. If your server is from MySQL 5.0.3 or
higher, but you have *Note `DECIMAL': numeric-types. columns in
tables that were created before 5.0.3, the old behavior still
applies to those columns. To convert the tables to the newer *Note
`DECIMAL': numeric-types. format, dump them with *Note
`mysqldump': mysqldump. and reload them.

* *Incompatible change:* MySQL 5.0.3 and up uses precision math when
calculating with *Note `DECIMAL': numeric-types. and integer
columns (64 decimal digits) and for rounding exact-value numbers.
Rounding behavior is well-defined, not dependent on the
implementation of the underlying C library. However, this might
result in incompatibilities for applications that rely on the old
behavior. (For example, inserting .5 into an *Note `INT':
numeric-types. column results in 1 as of MySQL 5.0.3, but might be
0 in older versions.) For more information about rounding
behavior, see *Note precision-math-rounding::, and *Note
precision-math-examples::.

* *Incompatible change*: `MyISAM' and `InnoDB' tables created with
*Note `DECIMAL': numeric-types. columns in MySQL 5.0.3 to 5.0.5
will appear corrupt after an upgrade to MySQL 5.0.6. (The same
incompatibility will occur for these tables created in MySQL 5.0.6
after a downgrade to MySQL 5.0.3 to 5.0.5.) If you have such
tables, check and repair them with *Note `mysql_upgrade':
mysql-upgrade. after upgrading. See *Note mysql-upgrade::.

* *Incompatible change:* For user-defined functions, exact-value
decimal arguments such as `1.3' or *Note `DECIMAL': numeric-types.
column values were passed as `REAL_RESULT' values prior to MySQL
5.0.3. As of 5.0.3, they are passed as strings with a type of
`DECIMAL_RESULT'. If you upgrade to 5.0.3 and find that your UDF
now receives string values, use the initialization function to
coerce the arguments to numbers as described in *Note
udf-arguments::.

* *Incompatible change*: As of MySQL 5.0.3, the server by default no
longer loads user-defined functions (UDFs) unless they have at
least one auxiliary symbol (for example, an `xxx_init' or
`xxx_deinit' symbol) defined in addition to the main function
symbol. This behavior can be overridden with the
`--allow-suspicious-udfs' option. See *Note udf-security::.

* *Incompatible change*: As of MySQL 5.0.13, `InnoDB' rolls back
only the last statement on a transaction timeout. As of MySQL
5.0.32, a new option, `--innodb_rollback_on_timeout', causes
`InnoDB' to abort and roll back the entire transaction if a
transaction timeout occurs (the same behavior as in MySQL 4.1).

* *Incompatible change*: For *Note `ENUM': enum. columns that had
enumeration values containing commas, the commas were mapped to
`0xff' internally. However, this rendered the commas
indistinguishable from true `0xff' characters in the values. This
no longer occurs. However, the fix requires that you dump and
reload any tables that have *Note `ENUM': enum. columns containing
true `0xff' in their values: Dump the tables using *Note
`mysqldump': mysqldump. with the current server before upgrading
from a version of MySQL 5.0 older than 5.0.36 to version 5.0.36 or
newer.

* *Incompatible change*: The update log has been removed in MySQL
5.0. If you had enabled it previously, enable the binary log
instead.

* *Incompatible change:* Support for the `ISAM' storage engine has
been removed in MySQL 5.0. If you have any `ISAM' tables, you
should convert them _before_ upgrading. For example, to convert an
`ISAM' table to use the `MyISAM' storage engine, use this
statement:

ALTER TABLE TBL_NAME ENGINE = MyISAM;

Use a similar statement for every `ISAM' table in each of your
databases.

* *Incompatible change*: Support for `RAID' options in `MyISAM'
tables has been removed in MySQL 5.0. If you have tables that use
these options, you should convert them before upgrading. One way
to do this is to dump them with *Note `mysqldump': mysqldump, edit
the dump file to remove the `RAID' options in the *Note `CREATE
TABLE': create-table. statements, and reload the dump file.
Another possibility is to use `CREATE TABLE NEW_TBL ... SELECT
RAID_TBL' to create a new table from the `RAID' table. However,
the *Note `CREATE TABLE': create-table. part of the statement
must contain sufficient information to re-create column attributes
as well as indexes, or column attributes may be lost and indexes
will not appear in the new table. See *Note create-table::.

The `.MYD' files for `RAID' tables in a given database are stored
under the database directory in subdirectories that have names
consisting of two hex digits in the range from `00' to `ff'. After
converting all tables that use `RAID' options, these `RAID'-related
subdirectories still will exist but can be removed. Verify that
they are empty, and then remove them manually. (If they are not
empty, this indicates that there is some `RAID' table that has not
been converted.)

* *Incompatible change*: Beginning with MySQL 5.0.42, when a *Note
`DATE': datetime. value is compared with a *Note `DATETIME':
datetime. value, the *Note `DATE': datetime. value is coerced to
the *Note `DATETIME': datetime. type by adding the time portion as
`00:00:00'. Previously, the time portion of the *Note `DATETIME':
datetime. value was ignored, or the comparison could be performed
as a string comparison. To mimic the old behavior, use the
`CAST()' function to cause the comparison operands to be treated
as previously. For example:

DATE_COL = CAST(NOW() AS DATE)

* *Incompatible change:* *Note `SHOW CREATE VIEW': show-create-view.
displays view definitions using an `AS ALIAS_NAME' clause for each
column. If a column is created from an expression, the default
alias is the expression text, which can be quite long. As of MySQL
5.0.52, aliases for column names in *Note `CREATE VIEW':
create-view. statements are checked against the maximum column
length of 64 characters (not the maximum alias length of 256
characters). As a result, views created from the output of *Note
`SHOW CREATE VIEW': show-create-view. fail if any column alias
exceeds 64 characters. This can cause problems for replication or
loading dump files. For additional information and workarounds, see
*Note view-restrictions::.

* As of MySQL 5.0.25, the `lc_time_names' system variable specifies
the locale that controls the language used to display day and
month names and abbreviations. This variable affects the output
from the `DATE_FORMAT()', `DAYNAME()' and `MONTHNAME()' functions.
See *Note locale-support::.

* In MySQL 5.0.6, binary logging of stored routines and triggers was
changed. This change has implications for security, replication,
and data recovery, as discussed in *Note stored-programs-logging::.

* As of MySQL 5.0.28, *Note `mysqld_safe': mysqld-safe. no longer
implicitly invokes `mysqld-max' if it exists. Instead, it invokes
*Note `mysqld': mysqld. unless a `--mysqld' or `--mysqld-version'
option is given to specify another server explicitly. If you
previously relied on the implicit invocation of `mysqld-max', you
should use an appropriate option now.

SQL Changes

* *Known issue*: Prior to MySQL 5.0.46, the parser accepted invalid
code in SQL condition handlers, leading to server crashes or
unexpected execution behavior in stored programs. Specifically,
the parser permitted a condition handler to refer to labels for
blocks that enclose the handler declaration. This was incorrect
because block label scope does not include the code for handlers
declared within the labeled block.

As of 5.0.46, the parser rejects this invalid construct, but if
you upgrade in place (without dumping and reloading your
databases), existing handlers that contain the construct still are
invalid _even if they appear to function as you expect_ and should
be rewritten.

To find affected handlers, use mysqldump to dump all stored
procedures and functions, triggers, and events. Then attempt to
reload them into an upgraded server. Handlers that contain illegal
label references will be rejected.

For more information about condition handlers and writing them to
avoid invalid jumps, see *Note declare-handler::.

* *Known issue*: The fix for Bug#23491
(http://bugs.mysql.com/bug.php?id=23491) introduced a problem with
*Note `SHOW CREATE VIEW': show-create-view, which is used by *Note
`mysqldump': mysqldump. This causes an incompatibility when
upgrading from versions affected by that bug fix (MySQL 5.0.40
through 5.0.43, MySQL 5.1.18 through 5.1.19): If you use *Note
`mysqldump': mysqldump. before upgrading from an affected version
and reload the data after upgrading to a higher version, you must
drop and recreate your views.

* *Incompatible change:* The parser accepted statements that
contained `/* ... */' that were not properly closed with `*/',
such as `SELECT 1 /* + 2'. As of MySQL 5.0.50, statements that
contain unclosed `/*'-comments now are rejected with a syntax
error.

This fix has the potential to cause incompatibilities. Because of
Bug#26302 (http://bugs.mysql.com/bug.php?id=26302), which caused
the trailing `*/' to be truncated from comments in views, stored
routines, triggers, and events, it is possible that objects of
those types may have been stored with definitions that now will be
rejected as syntactically invalid. Such objects should be dropped
and re-created so that their definitions do not contain truncated
comments. If a stored object definition contains only a single
statement (does not use a *Note `BEGIN ... END': begin-end. block)
and contains a comment within the statement, the comment should be
moved to follow the statement or the object should be rewritten to
use a *Note `BEGIN ... END': begin-end. block. For example, this
statement:

CREATE PROCEDURE p() SELECT 1 /* my comment */ ;

Can be rewritten in either of these ways:

CREATE PROCEDURE p() SELECT 1; /* my comment */
CREATE PROCEDURE p() BEGIN SELECT 1 /* my comment */ ; END;

* *Incompatible change*: If you have created a user-defined function
(UDF) with a given name and upgrade MySQL to a version that
implements a new built-in function with the same name, the UDF
becomes inaccessible. To correct this, use *Note `DROP FUNCTION':
drop-function. to drop the UDF, and then use *Note `CREATE
FUNCTION': create-function. to re-create the UDF with a different
nonconflicting name. If a new version of MySQL implements a
built-in function with the same name as an existing stored
function, you have two choices: Rename the stored function to use
a nonconflicting name, or change calls to the function so that
they use a database qualifier (that is, use `DB_NAME.FUNC_NAME()'
syntax). See *Note function-resolution::, for the rules describing
how the server interprets references to different kinds of
functions.

* *Incompatible change:* Beginning with MySQL 5.0.12, natural joins
and joins with `USING', including outer join variants, are
processed according to the SQL:2003 standard. The changes include
elimination of redundant output columns for `NATURAL' joins and
joins specified with a `USING' clause and proper ordering of
output columns. The precedence of the comma operator also now is
lower compared to `JOIN', `LEFT JOIN', and so forth.

* *Incompatible change:* The namespace for triggers changed in MySQL
5.0.10. Previously, trigger names had to be unique per table. Now
they must be unique within the schema (database). An implication
of this change is that *Note `DROP TRIGGER': drop-trigger. syntax
now uses a schema name instead of a table name (schema name is
optional and, if omitted, the current schema will be used).

When upgrading from a version of MySQL 5 older than 5.0.10 to
MySQL 5.0.10 or newer, you must drop all triggers and re-create
them or *Note `DROP TRIGGER': drop-trigger. will not work after
the upgrade. Here is a suggested procedure for doing this:

1. Upgrade to MySQL 5.0.10 or later to be able to access trigger
information in the *Note `INFORMATION_SCHEMA.TRIGGERS':
triggers-table. table. (This should work even for pre-5.0.10
triggers.)

2. Dump all trigger definitions using the following *Note
`SELECT': select. statement:

SELECT CONCAT('CREATE TRIGGER ', t.TRIGGER_SCHEMA, '.', t.TRIGGER_NAME,
' ', t.ACTION_TIMING, ' ', t.EVENT_MANIPULATION, ' ON ',
t.EVENT_OBJECT_SCHEMA, '.', t.EVENT_OBJECT_TABLE,
' FOR EACH ROW ', t.ACTION_STATEMENT, '//' )
INTO OUTFILE '/tmp/triggers.sql'
FROM INFORMATION_SCHEMA.TRIGGERS AS t;

The statement uses `INTO OUTFILE', so you must have the `FILE'
privilege. The file will be created on the server host. Use
a different file name if you like. To be 100% safe, inspect
the trigger definitions in the `triggers.sql' file, and
perhaps make a backup of the file.

3. Stop the server and drop all triggers by removing all `.TRG'
files in your database directories. Change location to your
data directory and issue this command:

shell> rm */*.TRG

4. Start the server and re-create all triggers using the
`triggers.sql' file:

mysql> delimiter // ;
mysql> source /tmp/triggers.sql //

5. Use the `SHOW TRIGGERS' statement to check that all triggers
were created successfully.

* *Incompatible change:* As of MySQL 5.0.15, the `CHAR()' function
returns a binary string rather than a string in the connection
character set. An optional `USING CHARSET_NAME' clause may be used
to produce a result in a specific character set instead. Also,
arguments larger than 256 produce multiple characters. They are no
longer interpreted modulo 256 to produce a single character each.
These changes may cause some incompatibilities:

* `CHAR(ORD('A')) = 'a'' is no longer true:

mysql> SELECT CHAR(ORD('A')) = 'a';
+----------------------+
| CHAR(ORD('A')) = 'a' |
+----------------------+
| 0 |
+----------------------+

To perform a case-insensitive comparison, you can produce a
result string in a nonbinary character set by adding a
`USING' clause or converting the result:

mysql> SELECT CHAR(ORD('A') USING latin1) = 'a';
+-----------------------------------+
| CHAR(ORD('A') USING latin1) = 'a' |
+-----------------------------------+
| 1 |
+-----------------------------------+
mysql> SELECT CONVERT(CHAR(ORD('A')) USING latin1) = 'a';
+--------------------------------------------+
| CONVERT(CHAR(ORD('A')) USING latin1) = 'a' |
+--------------------------------------------+
| 1 |
+--------------------------------------------+

* `CREATE TABLE ... SELECT CHAR(...)' produces a *Note
`VARBINARY': binary-varbinary. column, not a *Note
`VARCHAR': char. column. To produce a *Note `VARCHAR': char.
column, use `USING' or `CONVERT()' as just described to
convert the `CHAR()' result into a nonbinary character set.

* Previously, the following statements inserted the value
`0x00410041' (`'AA'' as a `ucs2' string) into the table:

CREATE TABLE t (ucs2_column CHAR(2) CHARACTER SET ucs2);
INSERT INTO t VALUES (CHAR(0x41,0x41));

As of MySQL 5.0.15, the statements insert a single `ucs2'
character with value `0x4141'.

* *Incompatible change:* By default, integer subtraction involving
an unsigned value should produce an unsigned result. Tracking of
the `unsignedness' of an expression was improved in MySQL 5.0.13.
This means that, in some cases where an unsigned subtraction would
have resulted in a signed integer, it now results in an unsigned
integer. One context in which this difference manifests itself is
when a subtraction involving an unsigned operand would be negative.

Suppose that `i' is a `TINYINT UNSIGNED' column and has a value of
0. The server evaluates the following expression using 64-bit
unsigned integer arithmetic with the following result:

mysql> SELECT i - 1 FROM t;
+----------------------+
| i - 1 |
+----------------------+
| 18446744073709551615 |
+----------------------+

If the expression is used in an `UPDATE t SET i = i - 1'
statement, the expression is evaluated and the result assigned to
`i' according to the usual rules for handling values outside the
column range or 0 to 255. That is, the value is clipped to the
nearest endpoint of the range. However, the result is
version-specific:

* Before MySQL 5.0.13, the expression is evaluated but is
treated as the equivalent 64-bit signed value (-1) for the
assignment. The value of -1 is clipped to the nearest
endpoint of the column range, resulting in a value of 0:

mysql> UPDATE t SET i = i - 1; SELECT i FROM t;
+------+
| i |
+------+
| 0 |
+------+

* As of MySQL 5.0.13, the expression is evaluated and retains
its unsigned attribute for the assignment. The value of
18446744073709551615 is clipped to the nearest endpoint of
the column range, resulting in a value of 255:

mysql> UPDATE t SET i = i - 1; SELECT i FROM t;
+------+
| i |
+------+
| 255 |
+------+

To get the older behavior, use `CAST()' to convert the expression
result to a signed value:

UPDATE t SET i = CAST(i - 1 AS SIGNED);

Alternatively, set the `NO_UNSIGNED_SUBTRACTION' SQL mode.
However, this will affect all integer subtractions involving
unsigned values.

* *Incompatible change:* Before MySQL 5.0.12, `NOW()' and
`SYSDATE()' return the same value (the time at which the statement
in which the function occurs begins executing). As of MySQL 5.0.12,
`SYSDATE()' returns the time at which it executes, which can
differ from the value returned by `NOW()'. For information about
the implications for binary logging, replication, and use of
indexes, see the description for `SYSDATE()' in *Note
date-and-time-functions:: and for `SET TIMESTAMP' in *Note
set-option::. To restore the former behavior for `SYSDATE()' and
cause it to be an alias for `NOW()', start the server with the
`--sysdate-is-now' option (available as of MySQL 5.0.20).

* *Incompatible change:* Before MySQL 5.0.13, `GREATEST(X,NULL)' and
`LEAST(X,NULL)' return X when X is a non-`NULL' value. As of
5.0.13, both functions return `NULL' if any argument is `NULL',
the same as Oracle. This change can cause problems for
applications that rely on the old behavior.

* *Incompatible change:* Before MySQL 5.0.8, conversion of *Note
`DATETIME': datetime. values to numeric form by adding zero
produced a result in `YYYYMMDDHHMMSS' format. The result of
`DATETIME+0' is now in `YYYYMMDDHHMMSS.000000' format.

* *Incompatible change:* In MySQL 5.0.6, the behavior of *Note `LOAD
DATA INFILE': load-data. and *Note `SELECT ... INTO OUTFILE':
select. has changed when the `FIELDS TERMINATED BY' and `FIELDS
ENCLOSED BY' values both are empty. Formerly, a column was read or
written using the display width of the column. For example,
`INT(4)' was read or written using a field with a width of 4. Now
columns are read and written using a field width wide enough to
hold all values in the field. However, data files written before
this change was made might not be reloaded correctly with *Note
`LOAD DATA INFILE': load-data. for MySQL 5.0.6 and up. This change
also affects data files read by *Note `mysqlimport': mysqlimport.
and written by *Note `mysqldump --tab': mysqldump, which use *Note
`LOAD DATA INFILE': load-data. and *Note `SELECT ... INTO
OUTFILE': select. For more information, see *Note load-data::.

* *Incompatible change:* Before MySQL 5.0.2, *Note `SHOW STATUS':
show-status. returned global status values. The default as of
5.0.2 is to return session values, which is incompatible with
previous versions. To issue a *Note `SHOW STATUS': show-status.
statement that will retrieve global status values for all versions
of MySQL, write it like this:

SHOW /*!50002 GLOBAL */ STATUS;

* *Incompatible change:* User variables are not case sensitive in
MySQL 5.0. In MySQL 4.1, `SET @x = 0; SET @X = 1; SELECT @x;'
created two variables and returned `0'. In MySQL 5.0, it creates
one variable and returns `1'. Replication setups that rely on the
old behavior may be affected by this change.

* Some keywords may be reserved in MySQL 5.0 that were not reserved
in MySQL 4.1. See *Note reserved-words::.

* The `LOAD DATA FROM MASTER' and `LOAD TABLE FROM MASTER'
statements are deprecated. See *Note load-data-from-master::, for
recommended alternatives.

* As of MySQL 5.0.25, *Note `TIMESTAMP': datetime. columns that are
`NOT NULL' now are reported that way by *Note `SHOW COLUMNS':
show-columns. and `INFORMATION_SCHEMA', rather than as `NULL'.

* Comparisons made between *Note `FLOAT': numeric-types. or *Note
`DOUBLE': numeric-types. values that happened to work in MySQL 4.1
may not do so in 5.0. Values of these types are imprecise in all
MySQL versions, and you are _strongly advised_ to avoid such
comparisons as `WHERE COL_NAME=SOME_DOUBLE', _regardless of the
MySQL version you are using_. See *Note problems-with-float::.

* As of MySQL 5.0.3, *Note `BIT': numeric-types. is a separate data
type, not a synonym for `TINYINT(1)'. See *Note
numeric-type-overview::.

* MySQL 5.0.2 adds several SQL modes that enable stricter control
over rejecting records that have invalid or missing values. See
*Note server-sql-mode::, and *Note constraint-invalid-data::. If
you want to enable this control but continue to use MySQL's
capability for storing incorrect dates such as `'2004-02-31'', you
should start the server with
`--sql_mode="TRADITIONAL,ALLOW_INVALID_DATES"'.

* As of MySQL 5.0.2, the `SCHEMA' and `SCHEMAS' keywords are
accepted as synonyms for `DATABASE' and `DATABASES', respectively.
(While `schemata' is grammatically correct and even appears in
some MySQL 5.0 system database and table names, it cannot be used
as a keyword.)

C API Changes

* *Incompatible change*: Because the MySQL 5.0 server has a new
implementation of the *Note `DECIMAL': numeric-types. data type, a
problem may occur if the server is used by older clients that still
are linked against MySQL 4.1 client libraries. If a client uses
the binary client/server protocol to execute prepared statements
that generate result sets containing numeric values, an error will
be raised: `'Using unsupported buffer type: 246''

This error occurs because the 4.1 client libraries do not support
the new `MYSQL_TYPE_NEWDECIMAL' type value added in 5.0. There is
no way to disable the new *Note `DECIMAL': numeric-types. data
type on the server side. You can avoid the problem by relinking the
application with the client libraries from MySQL 5.0.

* *Incompatible change*: The `ER_WARN_DATA_TRUNCATED' warning symbol
was renamed to `WARN_DATA_TRUNCATED' in MySQL 5.0.3.

* The `reconnect' flag in the `MYSQL' structure is set to 0 by *Note
`mysql_real_connect()': mysql-real-connect. Only those client
programs which did not explicitly set this flag to 0 or 1 after
*Note `mysql_real_connect()': mysql-real-connect. experience a
change. Having automatic reconnection enabled by default was
considered too dangerous (due to the fact that table locks,
temporary tables, user variables, and session variables are lost
after reconnection).

File: manual.info, Node: downgrading, Next: checking-table-incompatibilities, Prev: upgrading, Up: upgrading-downgrading

3.19.2 Downgrading MySQL
------------------------

* Menu:

* downgrading-to-previous-series:: Downgrading to MySQL 4.1

This section describes what you should do to downgrade to an older
MySQL version in the unlikely case that the previous version worked
better than the new one.

If you are downgrading within the same release series (for example,
from 4.1.13 to 4.1.12) the general rule is that you just have to
install the new binaries on top of the old ones. There is no need to do
anything with the databases. As always, however, it is always a good
idea to make a backup.

The following items form a checklist of things you should do whenever
you perform a downgrade:

* Read the upgrading section for the release series from which you
are downgrading to be sure that it does not have any features you
really need. See *Note upgrading::.

* If there is a downgrading section for that version, you should
read that as well.

* To see which new features were added between the version to which
you are downgrading and your current version, see the change logs
(*Note news::).

* Check *Note checking-table-incompatibilities::, to see whether
changes to table formats or to character sets or collations were
made between your current version of MySQL and the version to
which you are downgrading. If so and these changes result in an
incompatibility between MySQL versions, you will need to downgrade
the affected tables using the instructions in *Note
rebuilding-tables::.

In most cases, you can move the MySQL format files and data files
between different versions on the same architecture as long as you stay
within versions for the same release series of MySQL.

If you downgrade from one release series to another, there may be
incompatibilities in table storage formats. In this case, use *Note
`mysqldump': mysqldump. to dump your tables before downgrading. After
downgrading, reload the dump file using *Note `mysql': mysql. or *Note
`mysqlimport': mysqlimport. to re-create your tables. For examples, see
*Note copying-databases::.

A typical symptom of a downward-incompatible table format change when
you downgrade is that you cannot open tables. In that case, use the
following procedure:

1. Stop the older MySQL server that you are downgrading to.

2. Restart the newer MySQL server you are downgrading from.

3. Dump any tables that were inaccessible to the older server by
using *Note `mysqldump': mysqldump. to create a dump file.

4. Stop the newer MySQL server and restart the older one.

5. Reload the dump file into the older server. Your tables should be
accessible.

It might also be the case that system tables in the `mysql' database
have changed and that downgrading introduces some loss of functionality
or requires some adjustments. Here are some examples:

* Trigger creation requires the `TRIGGER' privilege as of MySQL 5.1.
In MySQL 5.0, there is no `TRIGGER' privilege and `SUPER' is
required instead. If you downgrade from MySQL 5.1 to 5.0, you will
need to give the `SUPER' privilege to those accounts that had the
`TRIGGER' privilege in 5.1.

* Triggers were added in MySQL 5.0, so if you downgrade from 5.0 to
4.1, you cannot use triggers at all.

* The `mysql.proc.comment' column definition changed between MySQL
5.1 and 5.5. After a downgrade from 5.5 to 5.1, this table is seen
as corrupt and in need of repair. To workaround this problem,
execute *Note `mysql_upgrade': mysql-upgrade. from the version of
MySQL to which you downgraded.

File: manual.info, Node: downgrading-to-previous-series, Prev: downgrading, Up: downgrading

3.19.2.1 Downgrading to MySQL 4.1
.................................

MySQL 4.1 does not support stored routines or triggers. If your
databases contain stored routines or triggers, prevent them from being
dumped when you use *Note `mysqldump': mysqldump. by using the
`--skip-routines' and `--skip-triggers' options. (See *Note
mysqldump::.)

MySQL 4.1 does not support views. If your databases contain views,
remove them with *Note `DROP VIEW': drop-view. before using *Note
`mysqldump': mysqldump. (See *Note drop-view::.)

After downgrading from MySQL 5.0, you may see the following information
in the `mysql.err' file:

Incorrect information in file: './mysql/user.frm'

In this case, you can do the following:

1. Start MySQL 5.0.4 (or newer).

2. Run *Note `mysql_fix_privilege_tables':
mysql-fix-privilege-tables, which will change the `mysql.user'
table to a format that both MySQL 4.1 and 5.0 can use.

3. Stop the MySQL server.

4. Start MySQL 4.1.

If the preceding procedure fails, you should be able to do the
following instead:

1. Start MySQL 5.0.4 (or newer).

2. Run *Note `mysqldump --opt --add-drop-table mysql >
/tmp/mysql.dump': mysqldump.

3. Stop the MySQL server.

4. Start MySQL 4.1 with the `--skip-grant-tables' option.

5. Run *Note `mysql mysql < /tmp/mysql.dump': mysql.

6. Run *Note `mysqladmin flush-privileges': mysqladmin.

File: manual.info, Node: checking-table-incompatibilities, Next: rebuilding-tables, Prev: downgrading, Up: upgrading-downgrading

3.19.3 Checking Whether Tables or Indexes Must Be Rebuilt
---------------------------------------------------------

A binary upgrade or downgrade is one that installs one version of MySQL
`in place' over an existing version, without dumping and reloading
tables:

1. Stop the server for the existing version if it is running.

2. Install a different version of MySQL. This is an upgrade if the
new version is higher than the original version, a downgrade if
the version is lower.

3. Start the server for the new version.

In many cases, the tables from the previous version of MySQL can be
used without problem by the new version. However, sometimes changes
occur that require tables or table indexes to be rebuilt, as described
in this section. If you have tables that are affected by any of the
issues described here, rebuild the tables or indexes as necessary using
the instructions given in *Note rebuilding-tables::.

Table Incompatibilities

After a binary upgrade to MySQL 5.1 from a MySQL 5.0 installation that
contains *Note `ARCHIVE': archive-storage-engine. tables, accessing
those tables causes the server to crash, even if you have run *Note
`mysql_upgrade': mysql-upgrade. or *Note `CHECK TABLE ... FOR UPGRADE':
check-table. To work around this problem, use *Note `mysqldump':
mysqldump. to dump all *Note `ARCHIVE': archive-storage-engine. tables
before upgrading, and reload them into MySQL 5.1 after upgrading. The
same problem occurs for binary downgrades from MySQL 5.1 to 5.0.

Index Incompatibilities

If you perform a binary upgrade without dumping and reloading tables,
you cannot upgrade directly from MySQL 4.1 to 5.1 or higher. This
occurs due to an incompatible change in the `MyISAM' table index format
in MySQL 5.0. Upgrade from MySQL 4.1 to 5.0 and repair all `MyISAM'
tables. Then upgrade from MySQL 5.0 to 5.1 and check and repair your
tables.

Modifications to the handling of character sets or collations might
change the character sort order, which causes the ordering of entries
in any index that uses an affected character set or collation to be
incorrect. Such changes result in several possible problems:

* Comparison results that differ from previous results

* Inability to find some index values due to misordered index entries

* Misordered `ORDER BY' results

* Tables that *Note `CHECK TABLE': check-table. reports as being in
need of repair

The solution to these problems is to rebuild any indexes that use an
affected character set or collation, either by dropping and re-creating
the indexes, or by dumping and reloading the entire table. For
information about rebuilding indexes, see *Note rebuilding-tables::.

To check whether a table has indexes that must be rebuilt, consult the
following list. It indicates which versions of MySQL introduced
character set or collation changes that require indexes to be rebuilt.
Each entry indicates the version in which the change occurred and the
character sets or collations that the change affects. If the change is
associated with a particular bug report, the bug number is given.

The list applies both for binary upgrades and downgrades. For example,
Bug#27877 (http://bugs.mysql.com/bug.php?id=27877) was fixed in MySQL
5.1.24 and 5.4.0, so it applies to upgrades from versions older than
5.1.24 to 5.1.24 or newer, and to downgrades from 5.1.24 or newer to
versions older than 5.1.24.

In many cases, you can use *Note `CHECK TABLE ... FOR UPGRADE':
check-table. to identify tables for which index rebuilding is required.
(It will report: `Table upgrade required. Please do "REPAIR TABLE
`tbl_name`" to fix it!') In these cases, you can also use *Note
`mysqlcheck --check-upgrade': mysqlcheck. or *Note `mysql_upgrade':
mysql-upgrade, which execute *Note `CHECK TABLE': check-table. However,
the use of *Note `CHECK TABLE': check-table. applies only after
upgrades, not downgrades. Also, *Note `CHECK TABLE': check-table. is
not applicable to all storage engines. For details about which storage
engines *Note `CHECK TABLE': check-table. supports, see *Note
check-table::.

Changes that cause index rebuilding to be necessary:

* MySQL 5.0.48, 5.1.21 (Bug#29461
(http://bugs.mysql.com/bug.php?id=29461))

Affects indexes for columns that use any of these character sets:
`eucjpms', `euc_kr', `gb2312', `latin7', `macce', `ujis'

Affected tables can be detected by *Note `CHECK TABLE ... FOR
UPGRADE': check-table. as of MySQL 5.1.29, 5.4.0 (see Bug#39585
(http://bugs.mysql.com/bug.php?id=39585)).

* MySQL 5.0.48, 5.1.23 (Bug#27562
(http://bugs.mysql.com/bug.php?id=27562))

Affects indexes that use the `ascii_general_ci' collation for
columns that contain any of these characters: `'`'' GRAVE ACCENT,
`'['' LEFT SQUARE BRACKET, `'\'' REVERSE SOLIDUS, `']'' RIGHT
SQUARE BRACKET, `'~'' TILDE

Affected tables can be detected by *Note `CHECK TABLE ... FOR
UPGRADE': check-table. as of MySQL 5.1.29, 5.4.0 (see Bug#39585
(http://bugs.mysql.com/bug.php?id=39585)).

* MySQL 5.1.24, 5.4.0 (Bug#27877
(http://bugs.mysql.com/bug.php?id=27877))

Affects indexes that use the `utf8_general_ci' or
`ucs2_general_ci' collation for columns that contain `'ss'' LATIN
SMALL LETTER SHARP S (German).

Affected tables can be detected by *Note `CHECK TABLE ... FOR
UPGRADE': check-table. as of MySQL 5.1.30, 5.4.0 (see Bug#40053
(http://bugs.mysql.com/bug.php?id=40053)).

File: manual.info, Node: rebuilding-tables, Next: copying-databases, Prev: checking-table-incompatibilities, Up: upgrading-downgrading

3.19.4 Rebuilding or Repairing Tables or Indexes
------------------------------------------------

This section describes how to rebuild a table. This can be necessitated
by changes to MySQL such as how data types are handled or changes to
character set handling. For example, an error in a collation might have
been corrected, necessitating a table rebuild to update the indexes for
character columns that use the collation. (For examples, see *Note
checking-table-incompatibilities::.) It might also be that a table
repair or upgrade should be done as indicated by a table check
operation such as that performed by `CHECK TABLE', *Note `mysqlcheck':
mysqlcheck, or *Note `mysql_upgrade': mysql-upgrade.

Methods for rebuilding a table include dumping and reloading it, or
using *Note `ALTER TABLE': alter-table. or *Note `REPAIR TABLE':
repair-table.

*Note*:

If you are rebuilding tables because a different version of MySQL will
not handle them after a binary (in-place) upgrade or downgrade, you
must use the dump-and-reload method. Dump the tables _before_ upgrading
or downgrading using your original version of MySQL. Then reload the
tables _after_ upgrading or downgrading.

If you use the dump-and-reload method of rebuilding tables only for the
purpose of rebuilding indexes, you can perform the dump either before
or after upgrading or downgrading. Reloading still must be done
afterward.

To rebuild a table by dumping and reloading it, use *Note `mysqldump':
mysqldump. to create a dump file and *Note `mysql': mysql. to reload
the file:

shell> mysqldump DB_NAME t1 > dump.sql
shell> mysql DB_NAME < dump.sql

To rebuild all the tables in a single database, specify the database
name without any following table name:

shell> mysqldump DB_NAME > dump.sql
shell> mysql DB_NAME < dump.sql

To rebuild all tables in all databases, use the `--all-databases'
option:

shell> mysqldump --all-databases > dump.sql
shell> mysql < dump.sql

To rebuild a table with *Note `ALTER TABLE': alter-table, use a `null'
alteration; that is, an *Note `ALTER TABLE': alter-table. statement that
`changes' the table to use the storage engine that it already has. For
example, if `t1' is a `MyISAM' table, use this statement:

mysql> ALTER TABLE t1 ENGINE = MyISAM;

If you are not sure which storage engine to specify in the *Note `ALTER
TABLE': alter-table. statement, use *Note `SHOW CREATE TABLE':
show-create-table. to display the table definition.

If you must rebuild a table because a table checking operation
indicates that the table is corrupt or needs an upgrade, you can use
*Note `REPAIR TABLE': repair-table. if that statement supports the
table's storage engine. For example, to repair a `MyISAM' table, use
this statement:

mysql> REPAIR TABLE t1;

For storage engines such as `InnoDB' that *Note `REPAIR TABLE':
repair-table. does not support, use *Note `mysqldump': mysqldump. to
create a dump file and *Note `mysql': mysql. to reload the file, as
described earlier.

For specifics about which storage engines *Note `REPAIR TABLE':
repair-table. supports, see *Note repair-table::.

*Note `mysqlcheck --repair': mysqlcheck. provides command-line access
to the *Note `REPAIR TABLE': repair-table. statement. This can be a
more convenient means of repairing tables because you can use the
`--databases' or `--all-databases' option to repair all tables in
specific databases or all databases, respectively:

shell> mysqlcheck --repair --databases DB_NAME ...
shell> mysqlcheck --repair --all-databases

File: manual.info, Node: copying-databases, Prev: rebuilding-tables, Up: upgrading-downgrading

3.19.5 Copying MySQL Databases to Another Machine
-------------------------------------------------

You can copy the `.frm', `.MYI', and `.MYD' files for `MyISAM' tables
between different architectures that support the same floating-point
format. (MySQL takes care of any byte-swapping issues.) See *Note
myisam-storage-engine::.

In cases where you need to transfer databases between different
architectures, you can use *Note `mysqldump': mysqldump. to create a
file containing SQL statements. You can then transfer the file to the
other machine and feed it as input to the *Note `mysql': mysql. client.

Use *Note `mysqldump --help': mysqldump. to see what options are
available.

The easiest (although not the fastest) way to move a database between
two machines is to run the following commands on the machine on which
the database is located:

shell> mysqladmin -h 'OTHER_HOSTNAME' create DB_NAME
shell> mysqldump DB_NAME | mysql -h 'OTHER_HOSTNAME' DB_NAME

If you want to copy a database from a remote machine over a slow
network, you can use these commands:

shell> mysqladmin create DB_NAME
shell> mysqldump -h 'OTHER_HOSTNAME' --compress DB_NAME | mysql DB_NAME

You can also store the dump in a file, transfer the file to the target
machine, and then load the file into the database there. For example,
you can dump a database to a compressed file on the source machine like
this:

shell> mysqldump --quick DB_NAME | gzip > DB_NAME.gz

Transfer the file containing the database contents to the target
machine and run these commands there:

shell> mysqladmin create DB_NAME
shell> gunzip < DB_NAME.gz | mysql DB_NAME

You can also use *Note `mysqldump': mysqldump. and *Note `mysqlimport':
mysqlimport. to transfer the database. For large tables, this is much
faster than simply using *Note `mysqldump': mysqldump. In the following
commands, DUMPDIR represents the full path name of the directory you
use to store the output from *Note `mysqldump': mysqldump.

First, create the directory for the output files and dump the database:

shell> mkdir DUMPDIR
shell> mysqldump --tab=DUMPDIR DB_NAME

Then transfer the files in the DUMPDIR directory to some corresponding
directory on the target machine and load the files into MySQL there:

shell> mysqladmin create DB_NAME # create database
shell> cat DUMPDIR/*.sql | mysql DB_NAME # create tables in database
shell> mysqlimport DB_NAME DUMPDIR/*.txt # load data into tables

Do not forget to copy the `mysql' database because that is where the
grant tables are stored. You might have to run commands as the MySQL
`root' user on the new machine until you have the `mysql' database in
place.

After you import the `mysql' database on the new machine, execute *Note
`mysqladmin flush-privileges': mysqladmin. so that the server reloads
the grant table information.

File: manual.info, Node: operating-system-specific-notes, Next: environment-variables, Prev: upgrading-downgrading, Up: installing

3.20 Operating System-Specific Notes
====================================

* Menu:

* linux:: Linux Notes
* macosx:: Mac OS X Notes
* solaris:: Solaris Notes
* bsd-notes:: BSD Notes
* other-unix-notes:: Other Unix Notes
* os-2:: OS/2 Notes

File: manual.info, Node: linux, Next: macosx, Prev: operating-system-specific-notes, Up: operating-system-specific-notes

3.20.1 Linux Notes
------------------

* Menu:

* linux-os:: Linux Operating System Notes
* binary-notes-linux:: Linux Binary Distribution Notes
* source-notes-linux:: Linux Source Distribution Notes
* linux-postinstallation:: Linux Postinstallation Notes
* linux-x86:: Linux x86 Notes
* linux-sparc:: Linux SPARC Notes
* linux-alpha:: Linux Alpha Notes
* linux-powerpc:: Linux PowerPC Notes
* linux-mips:: Linux MIPS Notes
* linux-ia-64:: Linux IA-64 Notes
* selinux:: SELinux Notes

This section discusses issues that have been found to occur on Linux.
The first few subsections describe general operating system-related
issues, problems that can occur when using binary or source
distributions, and postinstallation issues. The remaining subsections
discuss problems that occur with Linux on specific platforms.

Note that most of these problems occur on older versions of Linux. If
you are running a recent version, you may see none of them.

File: manual.info, Node: linux-os, Next: binary-notes-linux, Prev: linux, Up: linux

3.20.1.1 Linux Operating System Notes
.....................................

MySQL needs at least Linux version 2.0.

*Warning*:

We have seen some strange problems with Linux 2.2.14 and MySQL on SMP
systems. We also have reports from some MySQL users that they have
encountered serious stability problems using MySQL with kernel 2.2.14.
If you are using this kernel, you should upgrade to 2.2.19 (or newer)
or to a 2.4 kernel. If you have a multiple-CPU box, you should seriously
consider using 2.4 because it gives you a significant speed boost. Your
system should be more stable.

When using LinuxThreads, you should see a minimum of three *Note
`mysqld': mysqld. processes running. These are in fact threads. There
is one thread for the LinuxThreads manager, one thread to handle
connections, and one thread to handle alarms and signals.

File: manual.info, Node: binary-notes-linux, Next: source-notes-linux, Prev: linux-os, Up: linux

3.20.1.2 Linux Binary Distribution Notes
........................................

The Linux-Intel binary and RPM releases of MySQL are configured for the
highest possible speed. We are always trying to use the fastest stable
compiler available.

The binary release is linked with `-static', which means you do not
normally need to worry about which version of the system libraries you
have. You need not install LinuxThreads, either. A program linked with
`-static' is slightly larger than a dynamically linked program, but
also slightly faster (3% to 5%). However, one problem with a statically
linked program is that you can't use user-defined functions (UDFs). If
you are going to write or use UDFs (this is something for C or C++
programmers only), you must compile MySQL yourself using dynamic
linking.

A known issue with binary distributions is that on older Linux systems
that use `libc' (such as Red Hat 4.x or Slackware), you get some
(nonfatal) issues with host name resolution. If your system uses `libc'
rather than `glibc2', you probably will encounter some difficulties
with host name resolution and `getpwnam()'. This happens because
`glibc' (unfortunately) depends on some external libraries to implement
host name resolution and `getpwent()', even when compiled with
`-static'. These problems manifest themselves in two ways:

* You may see the following error message when you run *Note
`mysql_install_db': mysql-install-db.:

Sorry, the host 'XXXX' could not be looked up

You can deal with this by executing *Note `mysql_install_db
--force': mysql-install-db, which does not execute the *Note
`resolveip': resolveip. test in *Note `mysql_install_db':
mysql-install-db. The downside is that you cannot use host names
in the grant tables: except for `localhost', you must use IP
addresses instead. If you are using an old version of MySQL that
does not support `--force', you must manually remove the
`resolveip' test in *Note `mysql_install_db': mysql-install-db.
using a text editor.

* You also may see the following error when you try to run *Note
`mysqld': mysqld. with the `--user' option:

getpwnam: No such file or directory

To work around this problem, start *Note `mysqld': mysqld. by
using the `su' command rather than by specifying the `--user'
option. This causes the system itself to change the user ID of the
*Note `mysqld': mysqld. process so that *Note `mysqld': mysqld.
need not do so.

Another solution, which solves both problems, is not to use a binary
distribution. Obtain a MySQL source distribution (in RPM or `.tar.gz'
format) and install that instead.

On some Linux 2.2 versions, you may get the error `Resource temporarily
unavailable' when clients make a great many new connections to a *Note
`mysqld': mysqld. server over TCP/IP. The problem is that Linux has a
delay between the time that you close a TCP/IP socket and the time that
the system actually frees it. There is room for only a finite number
of TCP/IP slots, so you encounter the resource-unavailable error if
clients attempt too many new TCP/IP connections over a short period of
time. For example, you may see the error when you run the MySQL
`test-connect' benchmark over TCP/IP.

We have inquired about this problem a few times on different Linux
mailing lists but have never been able to find a suitable resolution.
The only known `fix' is for clients to use persistent connections, or,
if you are running the database server and clients on the same machine,
to use Unix socket file connections rather than TCP/IP connections.

File: manual.info, Node: source-notes-linux, Next: linux-postinstallation, Prev: binary-notes-linux, Up: linux

3.20.1.3 Linux Source Distribution Notes
........................................

The following notes regarding `glibc' apply only to the situation when
you build MySQL yourself. If you are running Linux on an x86 machine,
in most cases it is much better for you to use our binary. We link our
binaries against the best patched version of `glibc' we can find and
with the best compiler options, in an attempt to make it suitable for a
high-load server. For a typical user, even for setups with a lot of
concurrent connections or tables exceeding the 2GB limit, our binary is
the best choice in most cases. After reading the following text, if you
are in doubt about what to do, try our binary first to determine
whether it meets your needs. If you discover that it is not good enough,
you may want to try your own build. In that case, we would appreciate a
note about it so that we can build a better binary next time.

MySQL uses LinuxThreads on Linux. If you are using an old Linux version
that doesn't have `glibc2', you must install LinuxThreads before trying
to compile MySQL. You can obtain LinuxThreads from
`http://dev.mysql.com/downloads/os-linux.html'.

Note that `glibc' versions before and including version 2.1.1 have a
fatal bug in `pthread_mutex_timedwait()' handling, which is used when
*Note `INSERT DELAYED': insert-delayed. statements are issued. Do not
use *Note `INSERT DELAYED': insert-delayed. before upgrading `glibc'.

Note that Linux kernel and the LinuxThread library can by default
handle a maximum of 1,024 threads. If you plan to have more than 1,000
concurrent connections, you need to make some changes to LinuxThreads,
as follows:

* Increase `PTHREAD_THREADS_MAX' in
`sysdeps/unix/sysv/linux/bits/local_lim.h' to 4096 and decrease
`STACK_SIZE' in `linuxthreads/internals.h' to 256KB. The paths
are relative to the root of `glibc'. (Note that MySQL is not stable
with 600 to 1000 connections if `STACK_SIZE' is the default of
2MB.)

* Recompile LinuxThreads to produce a new `libpthread.a' library,
and relink MySQL against it.

There is another issue that greatly hurts MySQL performance, especially
on SMP systems. The mutex implementation in LinuxThreads in `glibc' 2.1
is very poor for programs with many threads that hold the mutex only
for a short time. This produces a paradoxical result: If you link MySQL
against an unmodified LinuxThreads, removing processors from an SMP
actually improves MySQL performance in many cases. We have made a
patch available for `glibc' 2.1.3 to correct this behavior
(`http://dev.mysql.com/Downloads/Linux/linuxthreads-2.1-patch').

With `glibc' 2.2.2, MySQL uses the adaptive mutex, which is much better
than even the patched one in `glibc' 2.1.3. Be warned, however, that
under some conditions, the current mutex code in `glibc' 2.2.2
overspins, which hurts MySQL performance. The likelihood that this
condition occurs can be reduced by re-nicing the *Note `mysqld':
mysqld. process to the highest priority. We have also been able to
correct the overspin behavior with a patch, available at
`http://dev.mysql.com/Downloads/Linux/linuxthreads-2.2.2.patch'. It
combines the correction of overspin, maximum number of threads, and
stack spacing all in one. You need to apply it in the `linuxthreads'
directory with `patch -p0 </tmp/linuxthreads-2.2.2.patch'. We hope it is
included in some form in future releases of `glibc' 2.2. In any case,
if you link against `glibc' 2.2.2, you still need to correct
`STACK_SIZE' and `PTHREAD_THREADS_MAX'. We hope that the defaults is
corrected to some more acceptable values for high-load MySQL setup in
the future, so that the commands needed to produce your own build can
be reduced to `./configure; make; make install'.

If you use these patches to build a special static version of
`libpthread.a', use it only for statically linking against MySQL. We
know that these patches are safe for MySQL and significantly improve
its performance, but we cannot say anything about their effects on
other applications. If you link other applications that require
LinuxThreads against the patched static version of the library, or
build a patched shared version and install it on your system, you do so
at your own risk.

If you experience any strange problems during the installation of
MySQL, or with some common utilities hanging, it is very likely that
they are either library or compiler related. If this is the case, using
our binary resolves them.

If you link your own MySQL client programs, you may see the following
error at runtime:

ld.so.1: fatal: libmysqlclient.so.#:
open failed: No such file or directory

This problem can be avoided by one of the following methods:

* Link clients with the `-Wl,r/full/path/to/libmysqlclient.so' flag
rather than with `-Lpath').

* Copy `libmysqclient.so' to `/usr/lib'.

* Add the path name of the directory where `libmysqlclient.so' is
located to the `LD_RUN_PATH' environment variable before running
your client.

If you are using the Fujitsu compiler (`fcc/FCC'), you may have some
problems compiling MySQL because the Linux header files are very `gcc'
oriented. The following `configure' line should work with `fcc/FCC':

CC=fcc CFLAGS="-O -K fast -K lib -K omitfp -Kpreex -D_GNU_SOURCE \
-DCONST=const -DNO_STRTOLL_PROTO" \
CXX=FCC CXXFLAGS="-O -K fast -K lib \
-K omitfp -K preex --no_exceptions --no_rtti -D_GNU_SOURCE \
-DCONST=const -Dalloca=__builtin_alloca -DNO_STRTOLL_PROTO \
'-D_EXTERN_INLINE=static __inline'" \
./configure \
--prefix=/usr/local/mysql --enable-assembler \
--with-mysqld-ldflags=-all-static --disable-shared \
--with-low-memory

File: manual.info, Node: linux-postinstallation, Next: linux-x86, Prev: source-notes-linux, Up: linux

3.20.1.4 Linux Postinstallation Notes
.....................................

*Note `mysql.server': mysql-server. can be found in the `support-files'
directory under the MySQL installation directory or in a MySQL source
tree. You can install it as `/etc/init.d/mysql' for automatic MySQL
startup and shutdown. See *Note automatic-start::.

If MySQL cannot open enough files or connections, it may be that you
have not configured Linux to handle enough files.

In Linux 2.2 and onward, you can check the number of allocated file
handles as follows:

shell> cat /proc/sys/fs/file-max
shell> cat /proc/sys/fs/dquot-max
shell> cat /proc/sys/fs/super-max

If you have more than 16MB of memory, you should add something like the
following to your init scripts (for example, `/etc/init.d/boot.local'
on SuSE Linux):

echo 65536 > /proc/sys/fs/file-max
echo 8192 > /proc/sys/fs/dquot-max
echo 1024 > /proc/sys/fs/super-max

You can also run the `echo' commands from the command line as `root',
but these settings are lost the next time your computer restarts.

Alternatively, you can set these parameters on startup by using the
`sysctl' tool, which is used by many Linux distributions (including
SuSE Linux 8.0 and later). Put the following values into a file named
`/etc/sysctl.conf':

# Increase some values for MySQL
fs.file-max = 65536
fs.dquot-max = 8192
fs.super-max = 1024

You should also add the following to `/etc/my.cnf':

[mysqld_safe]
open-files-limit=8192

This should enable a server limit of 8,192 for the combined number of
connections and open files.

The `STACK_SIZE' constant in LinuxThreads controls the spacing of
thread stacks in the address space. It needs to be large enough so that
there is plenty of room for each individual thread stack, but small
enough to keep the stack of some threads from running into the global
*Note `mysqld': mysqld. data. Unfortunately, as we have experimentally
discovered, the Linux implementation of `mmap()' successfully unmaps a
mapped region if you ask it to map out an address currently in use,
zeroing out the data on the entire page instead of returning an error.
So, the safety of *Note `mysqld': mysqld. or any other threaded
application depends on the `gentlemanly' behavior of the code that
creates threads. The user must take measures to make sure that the
number of running threads at any given time is sufficiently low for
thread stacks to stay away from the global heap. With *Note `mysqld':
mysqld, you should enforce this behavior by setting a reasonable value
for the `max_connections' variable.

If you build MySQL yourself, you can patch LinuxThreads for better
stack use. See *Note source-notes-linux::. If you do not want to patch
LinuxThreads, you should set `max_connections' to a value no higher
than 500. It should be even less if you have a large key buffer, large
heap tables, or some other things that make *Note `mysqld': mysqld.
allocate a lot of memory, or if you are running a 2.2 kernel with a 2GB
patch. If you are using our binary or RPM version, you can safely set
`max_connections' at 1500, assuming no large key buffer or heap tables
with lots of data. The more you reduce `STACK_SIZE' in LinuxThreads
the more threads you can safely create. Values between 128KB and 256KB
are recommended.

If you use a lot of concurrent connections, you may suffer from a
`feature' in the 2.2 kernel that attempts to prevent fork bomb attacks
by penalizing a process for forking or cloning a child. This causes
MySQL not to scale well as you increase the number of concurrent
clients. On single-CPU systems, we have seen this manifest as very slow
thread creation; it may take a long time to connect to MySQL (as long
as one minute), and it may take just as long to shut it down. On
multiple-CPU systems, we have observed a gradual drop in query speed as
the number of clients increases. In the process of trying to find a
solution, we have received a kernel patch from one of our users who
claimed it helped for his site. This patch is available at
`http://dev.mysql.com/Downloads/Patches/linux-fork.patch'. We have
done rather extensive testing of this patch on both development and
production systems. It has significantly improved MySQL performance
without causing any problems and is recommended for users who still run
high-load servers on 2.2 kernels.

This issue has been fixed in the 2.4 kernel, so if you are not
satisfied with the current performance of your system, rather than
patching your 2.2 kernel, it might be easier to upgrade to 2.4. On SMP
systems, upgrading also gives you a nice SMP boost in addition to
fixing the fairness bug.

We have tested MySQL on the 2.4 kernel on a two-CPU machine and found
MySQL scales _much_ better. There was virtually no slowdown on query
throughput all the way up to 1,000 clients, and the MySQL scaling
factor (computed as the ratio of maximum throughput to the throughput
for one client) was 180%. We have observed similar results on a
four-CPU system: Virtually no slowdown as the number of clients was
increased up to 1,000, and a 300% scaling factor. Based on these
results, for a high-load SMP server using a 2.2 kernel, it is
definitely recommended to upgrade to the 2.4 kernel at this point.

We have discovered that it is essential to run the *Note `mysqld':
mysqld. process with the highest possible priority on the 2.4 kernel to
achieve maximum performance. This can be done by adding a `renice -20
$$' command to *Note `mysqld_safe': mysqld-safe. In our testing on a
four-CPU machine, increasing the priority resulted in a 60% throughput
increase with 400 clients.

We are currently also trying to collect more information on how well
MySQL performs with a 2.4 kernel on four-way and eight-way systems. If
you have access such a system and have done some benchmarks, please
send an email message to <benchmarks@mysql.com> with the results. We
will review them for inclusion in the manual.

If you see a dead *Note `mysqld': mysqld. server process with `ps',
this usually means that you have found a bug in MySQL or you have a
corrupted table. See *Note crashing::.

To get a core dump on Linux if *Note `mysqld': mysqld. dies with a
`SIGSEGV' signal, you can start *Note `mysqld': mysqld. with the
`--core-file' option. Note that you also probably need to raise the
core file size by adding `ulimit -c 1000000' to *Note `mysqld_safe':
mysqld-safe. or starting *Note `mysqld_safe': mysqld-safe. with
`--core-file-size=1000000'. See *Note mysqld-safe::.

File: manual.info, Node: linux-x86, Next: linux-sparc, Prev: linux-postinstallation, Up: linux

3.20.1.5 Linux x86 Notes
........................

MySQL requires `libc' 5.4.12 or newer. It is known to work with `libc'
5.4.46. `glibc' 2.0.6 and later should also work. There have been
some problems with the `glibc' RPMs from Red Hat, so if you have
problems, check whether there are any updates. The `glibc' 2.0.7-19 and
2.0.7-29 RPMs are known to work.

If you are using Red Hat 8.0 or a new `glibc' 2.2.x library, you may
see *Note `mysqld': mysqld. die in `gethostbyaddr()'. This happens
because the new `glibc' library requires a stack size greater than
128KB for this call. To fix the problem, start *Note `mysqld': mysqld.
with the `--thread-stack=192K' option. This stack size is the default
on MySQL 4.0.10 and above, so you should not see the problem.

If you are using `gcc' 3.0 and above to compile MySQL, you must install
the `libstdc++v3' library before compiling MySQL; if you do not do
this, you get an error about a missing `__cxa_pure_virtual' symbol
during linking.

On some older Linux distributions, `configure' may produce an error
like this:

Syntax error in sched.h. Change _P to __P in the
/usr/include/sched.h file.
See the Installation chapter in the Reference Manual.

Just do what the error message says. Add an extra underscore to the
`_P' macro name that has only one underscore, and then try again.

You may get some warnings when compiling. Those shown here can be
ignored:

mysqld.cc -o objs-thread/mysqld.o
mysqld.cc: In function `void init_signals()':
mysqld.cc:315: warning: assignment of negative value `-1' to
`long unsigned int'
mysqld.cc: In function `void * signal_hand(void *)':
mysqld.cc:346: warning: assignment of negative value `-1' to
`long unsigned int'

If *Note `mysqld': mysqld. always dumps core when it starts, the
problem may be that you have an old `/lib/libc.a'. Try renaming it, and
then remove `sql/mysqld' and do a new `make install' and try again.
This problem has been reported on some Slackware installations.

If you get the following error when linking *Note `mysqld': mysqld, it
means that your `libg++.a' is not installed correctly:

/usr/lib/libc.a(putc.o): In function `_IO_putc':
putc.o(.text+0x0): multiple definition of `_IO_putc'

You can avoid using `libg++.a' by running `configure' like this:

shell> CXX=gcc ./configure

File: manual.info, Node: linux-sparc, Next: linux-alpha, Prev: linux-x86, Up: linux

3.20.1.6 Linux SPARC Notes
..........................

In some implementations, `readdir_r()' is broken. The symptom is that
the *Note `SHOW DATABASES': show-databases. statement always returns an
empty set. This can be fixed by removing `HAVE_READDIR_R' from
`config.h' after configuring and before compiling.

File: manual.info, Node: linux-alpha, Next: linux-powerpc, Prev: linux-sparc, Up: linux

3.20.1.7 Linux Alpha Notes
..........................

We have tested MySQL 5.0 on Alpha with our benchmarks and test suite,
and it appears to work well.

We currently build the MySQL binary packages on SuSE Linux 7.0 for AXP,
kernel 2.4.4-SMP, Compaq C compiler (V6.2-505) and Compaq C++ compiler
(V6.3-006) on a Compaq DS20 machine with an Alpha EV6 processor.

You can find the preceding compilers at
`http://www.support.compaq.com/alpha-tools/'. By using these compilers
rather than `gcc', we get about 9% to 14% better MySQL performance.

For MySQL on Alpha, we use the `-arch generic' flag to our compile
options, which ensures that the binary runs on all Alpha processors. We
also compile statically to avoid library problems. The `configure'
command looks like this:

CC=ccc CFLAGS="-fast -arch generic" CXX=cxx \
CXXFLAGS="-fast -arch generic -noexceptions -nortti" \
./configure --prefix=/usr/local/mysql --disable-shared \
--with-extra-charsets=complex --enable-thread-safe-client \
--with-mysqld-ldflags=-non_shared --with-client-ldflags=-non_shared

Some known problems when running MySQL on Linux-Alpha:

* Debugging threaded applications like MySQL does not work with `gdb
4.18'. You should use `gdb' 5.1 instead.

* If you try linking *Note `mysqld': mysqld. statically when using
`gcc', the resulting image dumps core at startup time. In other
words, _do not_ use `--with-mysqld-ldflags=-all-static' with `gcc'.

File: manual.info, Node: linux-powerpc, Next: linux-mips, Prev: linux-alpha, Up: linux

3.20.1.8 Linux PowerPC Notes
............................

MySQL should work on MkLinux with the newest `glibc' package (tested
with `glibc' 2.0.7).

File: manual.info, Node: linux-mips, Next: linux-ia-64, Prev: linux-powerpc, Up: linux

3.20.1.9 Linux MIPS Notes
.........................

To get MySQL to work on Qube2 (Linux Mips), you need the newest `glibc'
libraries. `glibc-2.0.7-29C2' is known to work. You must also use
`gcc' 2.95.2 or newer).

File: manual.info, Node: linux-ia-64, Next: selinux, Prev: linux-mips, Up: linux

3.20.1.10 Linux IA-64 Notes
...........................

To get MySQL to compile on Linux IA-64, we use the following
`configure' command for building with `gcc' 2.96:

CC=gcc \
CFLAGS="-O3 -fno-omit-frame-pointer" \
CXX=gcc \
CXXFLAGS="-O3 -fno-omit-frame-pointer -felide-constructors \
-fno-exceptions -fno-rtti" \
./configure --prefix=/usr/local/mysql \
"--with-comment=Official MySQL binary" \
--with-extra-charsets=complex

On IA-64, the MySQL client binaries use shared libraries. This means
that if you install our binary distribution at a location other than
`/usr/local/mysql', you need to add the path of the directory where you
have `libmysqlclient.so' installed either to the `/etc/ld.so.conf' file
or to the value of your `LD_LIBRARY_PATH' environment variable.

See *Note c-api-linking-problems::.

File: manual.info, Node: selinux, Prev: linux-ia-64, Up: linux

3.20.1.11 SELinux Notes
.......................

RHEL4 comes with SELinux, which supports tighter access control for
processes. If SELinux is enabled (`SELINUX' in `/etc/selinux/config' is
set to `enforcing', `SELINUXTYPE' is set to either `targeted' or
`strict'), you might encounter problems installing Oracle Corporation
RPM packages.

Red Hat has an update that solves this. It involves an update of the
`security policy' specification to handle the install structure of the
RPMs provided by Oracle Corporation. For further information, see
`https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=167551' and
`http://rhn.redhat.com/errata/RHBA-2006-0049.html'.

File: manual.info, Node: macosx, Next: solaris, Prev: linux, Up: operating-system-specific-notes

3.20.2 Mac OS X Notes
---------------------

* Menu:

* macosx-10-x:: Mac OS X 10.x (Darwin)
* macosx-server:: Mac OS X Server 1.2 (Rhapsody)

On Mac OS X, `tar' cannot handle long file names. If you need to unpack
a `.tar.gz' distribution, use `gnutar' instead.

File: manual.info, Node: macosx-10-x, Next: macosx-server, Prev: macosx, Up: macosx

3.20.2.1 Mac OS X 10.x (Darwin)
...............................

MySQL should work without major problems on Mac OS X 10.x (Darwin).

Known issues:

* If you have problems with performance under heavy load, try using
the `--skip-thread-priority' option to *Note `mysqld': mysqld.
This runs all threads with the same priority. On Mac OS X, this
gives better performance, at least until Apple fixes its thread
scheduler.

* The connection times (`wait_timeout', `interactive_timeout' and
`net_read_timeout') values are not honored.

This is probably a signal handling problem in the thread library
where the signal doesn't break a pending read and we hope that a
future update to the thread libraries will fix this.

Our binary for Mac OS X is compiled on Darwin 6.3 with the following
`configure' line:

CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc \
CXXFLAGS="-O3 -fno-omit-frame-pointer -felide-constructors \
-fno-exceptions -fno-rtti" \
./configure --prefix=/usr/local/mysql \
--with-extra-charsets=complex --enable-thread-safe-client \
--enable-local-infile --disable-shared

See *Note macosx-installation::.

File: manual.info, Node: macosx-server, Prev: macosx-10-x, Up: macosx

3.20.2.2 Mac OS X Server 1.2 (Rhapsody)
.......................................

For current versions of Mac OS X Server, no operating system changes
are necessary before compiling MySQL. Compiling for the Server platform
is the same as for the client version of Mac OS X.

For older versions (Mac OS X Server 1.2, a.k.a. Rhapsody), you must
first install a pthread package before trying to configure MySQL.

See *Note macosx-installation::.

File: manual.info, Node: solaris, Next: bsd-notes, Prev: macosx, Up: operating-system-specific-notes

3.20.3 Solaris Notes
--------------------

* Menu:

* solaris-2-7:: Solaris 2.7/2.8 Notes
* solaris-x86:: Solaris x86 Notes

For information about installing MySQL on Solaris using PKG
distributions, see *Note solaris-installation::.

On Solaris, you may run into trouble even before you get the MySQL
distribution unpacked, as the Solaris `tar' cannot handle long file
names. This means that you may see errors when you try to unpack MySQL.

If this occurs, you must use GNU `tar' (`gtar') to unpack the
distribution.

If you get the following error from `configure', it means that you have
something wrong with your compiler installation:

checking for restartable system calls... configure: error can not
run test programs while cross compiling

In this case, you should upgrade your compiler to a newer version. You
may also be able to solve this problem by inserting the following row
into the `config.cache' file:

ac_cv_sys_restartable_syscalls=${ac_cv_sys_restartable_syscalls='no'}

If you are using Solaris on a SPARC, the recommended compiler is `gcc'
2.95.2 or 3.2. You can find this at `http://gcc.gnu.org/'. Note that
`gcc' 2.8.1 does not work reliably on SPARC.

The recommended `configure' line when using `gcc' 2.95.2 is:

CC=gcc CFLAGS="-O3" \
CXX=gcc CXXFLAGS="-O3 -felide-constructors -fno-exceptions -fno-rtti" \
./configure --prefix=/usr/local/mysql --with-low-memory \
--enable-assembler

If you have an UltraSPARC system, you can get 4% better performance by
adding `-mcpu=v8 -Wa,-xarch=v8plusa' to the `CFLAGS' and `CXXFLAGS'
environment variables.

If you have Sun's Forte 5.0 (or newer) compiler, you can run
`configure' like this:

CC=cc CFLAGS="-Xa -fast -native -xstrconst -mt" \
CXX=CC CXXFLAGS="-noex -mt" \
./configure --prefix=/usr/local/mysql --enable-assembler

To create a 64-bit binary with Sun's Forte compiler, use the following
configuration options:

CC=cc CFLAGS="-Xa -fast -native -xstrconst -mt -xarch=v9" \
CXX=CC CXXFLAGS="-noex -mt -xarch=v9" ASFLAGS="-xarch=v9" \
./configure --prefix=/usr/local/mysql --enable-assembler

To create a 64-bit Solaris binary using `gcc', add `-m64' to `CFLAGS'
and `CXXFLAGS' and remove `--enable-assembler' from the `configure'
line.

In the MySQL benchmarks, we obtained a 4% speed increase on UltraSPARC
when using Forte 5.0 in 32-bit mode, as compared to using `gcc' 3.2
with the `-mcpu' flag.

If you create a 64-bit *Note `mysqld': mysqld. binary, it is 4% slower
than the 32-bit binary, but can handle more threads and memory.

When using Solaris 10 for x86_64, you should mount any file systems on
which you intend to store `InnoDB' files with the `forcedirectio'
option. (By default mounting is done without this option.) Failing to
do so will cause a significant drop in performance when using the
`InnoDB' storage engine on this platform.

If you get a problem with `fdatasync' or `sched_yield', you can fix
this by adding `LIBS=-lrt' to the `configure' line

For compilers older than WorkShop 5.3, you might have to edit the
`configure' script. Change this line:

#if !defined(__STDC__) || __STDC__ != 1

To this:

#if !defined(__STDC__)

If you turn on `__STDC__' with the `-Xc' option, the Sun compiler can't
compile with the Solaris `pthread.h' header file. This is a Sun bug
(broken compiler or broken include file).

If *Note `mysqld': mysqld. issues the following error message when you
run it, you have tried to compile MySQL with the Sun compiler without
enabling the `-mt' multi-thread option:

libc internal error: _rmutex_unlock: rmutex not held

Add `-mt' to `CFLAGS' and `CXXFLAGS' and recompile.

If you are using the SFW version of `gcc' (which comes with Solaris 8),
you must add `/opt/sfw/lib' to the environment variable
`LD_LIBRARY_PATH' before running `configure'.

If you are using the `gcc' available from `sunfreeware.com', you may
have many problems. To avoid this, you should recompile `gcc' and GNU
`binutils' on the machine where you are running them.

If you get the following error when compiling MySQL with `gcc', it
means that your `gcc' is not configured for your version of Solaris:

shell> gcc -O3 -g -O2 -DDBUG_OFF -o thr_alarm ...
./thr_alarm.c: In function `signal_hand':
./thr_alarm.c:556: too many arguments to function `sigwait'

The proper thing to do in this case is to get the newest version of
`gcc' and compile it with your current `gcc' compiler. At least for
Solaris 2.5, almost all binary versions of `gcc' have old, unusable
include files that break all programs that use threads, and possibly
other programs as well.

Solaris does not provide static versions of all system libraries
(`libpthreads' and `libdl'), so you cannot compile MySQL with
`--static'. If you try to do so, you get one of the following errors:

ld: fatal: library -ldl: not found
undefined reference to `dlopen'
cannot find -lrt

If you link your own MySQL client programs, you may see the following
error at runtime:

ld.so.1: fatal: libmysqlclient.so.#:
open failed: No such file or directory

This problem can be avoided by one of the following methods:

* Link clients with the `-Wl,r/full/path/to/libmysqlclient.so' flag
rather than with `-Lpath').

* Copy `libmysqclient.so' to `/usr/lib'.

* Add the path name of the directory where `libmysqlclient.so' is
located to the `LD_RUN_PATH' environment variable before running
your client.

If you have problems with `configure' trying to link with `-lz' when
you do not have `zlib' installed, you have two options:

* If you want to be able to use the compressed communication
protocol, you need to get and install `zlib' from `ftp.gnu.org'.

* Run `configure' with the `--with-named-z-libs=no' option when
building MySQL.

If you are using `gcc' and have problems with loading user-defined
functions (UDFs) into MySQL, try adding `-lgcc' to the link line for
the UDF.

If you would like MySQL to start automatically, you can copy
`support-files/mysql.server' to `/etc/init.d' and create a symbolic
link to it named `/etc/rc3.d/S99mysql.server'.

If too many processes try to connect very rapidly to *Note `mysqld':
mysqld, you should see this error in the MySQL log:

Error in accept: Protocol error

You might try starting the server with the `--back_log=50' option as a
workaround for this. (Use `-O back_log=50' before MySQL 4.)

To configure the generation of core files on Solaris you should use the
`coreadm' command. Because of the security implications of generating a
core on a `setuid()' application, by default, Solaris does not support
core files on `setuid()' programs. However, you can modify this
behavior using `coreadm'. If you enable `setuid()' core files for the
current user, they will be generated using the mode 600 and owned by the
superuser.

File: manual.info, Node: solaris-2-7, Next: solaris-x86, Prev: solaris, Up: solaris

3.20.3.1 Solaris 2.7/2.8 Notes
..............................

Normally, you can use a Solaris 2.6 binary on Solaris 2.7 and 2.8. Most
of the Solaris 2.6 issues also apply for Solaris 2.7 and 2.8.

MySQL should be able to detect new versions of Solaris automatically
and enable workarounds for the following problems.

Solaris 2.7 / 2.8 has some bugs in the include files. You may see the
following error when you use `gcc':

/usr/include/widec.h:42: warning: `getwc' redefined
/usr/include/wchar.h:326: warning: this is the location of the previous
definition

If this occurs, you can fix the problem by copying
`/usr/include/widec.h' to `.../lib/gcc-lib/os/gcc-version/include' and
changing line 41 from this:

#if !defined(lint) && !defined(__lint)

To this:

#if !defined(lint) && !defined(__lint) && !defined(getwc)

Alternatively, you can edit `/usr/include/widec.h' directly. Either
way, after you make the fix, you should remove `config.cache' and run
`configure' again.

If you get the following errors when you run `make', it is because
`configure' didn't detect the `curses.h' file (probably because of the
error in `/usr/include/widec.h'):

In file included from mysql.cc:50:
/usr/include/term.h:1060: syntax error before `,'
/usr/include/term.h:1081: syntax error before `;'

The solution to this problem is to do one of the following:

1. Configure with `CFLAGS=-DHAVE_CURSES_H CXXFLAGS=-DHAVE_CURSES_H
./configure'.

2. Edit `/usr/include/widec.h' as indicated in the preceding
discussion and re-run `configure'.

3. Remove the `#define HAVE_TERM' line from the `config.h' file and
run `make' again.

If your linker cannot find `-lz' when linking client programs, the
problem is probably that your `libz.so' file is installed in
`/usr/local/lib'. You can fix this problem by one of the following
methods:

* Add `/usr/local/lib' to `LD_LIBRARY_PATH'.

* Add a link to `libz.so' from `/lib'.

* If you are using Solaris 8, you can install the optional `zlib'
from your Solaris 8 CD distribution.

* Run `configure' with the `--with-named-z-libs=no' option when
building MySQL.

File: manual.info, Node: solaris-x86, Prev: solaris-2-7, Up: solaris

3.20.3.2 Solaris x86 Notes
..........................

On Solaris 8 on x86, *Note `mysqld': mysqld. dumps core if you remove
the debug symbols using `strip'.

If you are using `gcc' on Solaris x86 and you experience problems with
core dumps under load, you should use the following `configure' command:

CC=gcc CFLAGS="-O3 -fomit-frame-pointer -DHAVE_CURSES_H" \
CXX=gcc \
CXXFLAGS="-O3 -fomit-frame-pointer -felide-constructors \
-fno-exceptions -fno-rtti -DHAVE_CURSES_H" \
./configure --prefix=/usr/local/mysql

This avoids problems with the `libstdc++' library and with C++
exceptions.

If this doesn't help, you should compile a debug version and run it
with a trace file or under `gdb'. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

File: manual.info, Node: bsd-notes, Next: other-unix-notes, Prev: solaris, Up: operating-system-specific-notes

3.20.4 BSD Notes
----------------

* Menu:

* freebsd:: FreeBSD Notes
* netbsd:: NetBSD Notes
* openbsd:: OpenBSD 2.5 Notes
* bsdi:: BSD/OS Version 2.x Notes
* bsdi3:: BSD/OS Version 3.x Notes
* bsdi4:: BSD/OS Version 4.x Notes

This section provides information about using MySQL on variants of BSD
Unix.

File: manual.info, Node: freebsd, Next: netbsd, Prev: bsd-notes, Up: bsd-notes

3.20.4.1 FreeBSD Notes
......................

FreeBSD 4.x or newer is recommended for running MySQL, because the
thread package is much more integrated. To get a secure and stable
system, you should use only FreeBSD kernels that are marked `-RELEASE'.

The easiest (and preferred) way to install MySQL is to use the *Note
`mysql-server': mysql-server. and `mysql-client' ports available at
`http://www.freebsd.org/'. Using these ports gives you the following
benefits:

* A working MySQL with all optimizations enabled that are known to
work on your version of FreeBSD.

* Automatic configuration and build.

* Startup scripts installed in `/usr/local/etc/rc.d'.

* The ability to use `pkg_info -L' to see which files are installed.

* The ability to use `pkg_delete' to remove MySQL if you no longer
want it on your machine.

It is recommended you use MIT-pthreads on FreeBSD 2.x, and native
threads on FreeBSD 3 and up. It is possible to run with native threads
on some late 2.2.x versions, but you may encounter problems shutting
down *Note `mysqld': mysqld.

Unfortunately, certain function calls on FreeBSD are not yet fully
thread-safe. Most notably, this includes the `gethostbyname()'
function, which is used by MySQL to convert host names into IP
addresses. Under certain circumstances, the *Note `mysqld': mysqld.
process suddenly causes 100% CPU load and is unresponsive. If you
encounter this problem, try to start MySQL using the
`--skip-name-resolve' option.

Alternatively, you can link MySQL on FreeBSD 4.x against the
LinuxThreads library, which avoids a few of the problems that the
native FreeBSD thread implementation has. For a very good comparison of
LinuxThreads versus native threads, see Jeremy Zawodny's article
`FreeBSD or Linux for your MySQL Server?' at
`http://jeremy.zawodny.com/blog/archives/000697.html'.

Known problem when using LinuxThreads on FreeBSD is:

* The connection times (`wait_timeout', `interactive_timeout' and
`net_read_timeout') values are not honored. The symptom is that
persistent connections can hang for a very long time without
getting closed down and that a 'kill' for a thread will not take
affect until the thread does it a new command

This is probably a signal handling problem in the thread library
where the signal doesn't break a pending read. This is supposed
to be fixed in FreeBSD 5.0

The MySQL build process requires GNU make (`gmake') to work. If GNU
`make' is not available, you must install it first before compiling
MySQL.

The recommended way to compile and install MySQL on FreeBSD with `gcc'
(2.95.2 and up) is:

CC=gcc CFLAGS="-O2 -fno-strength-reduce" \
CXX=gcc CXXFLAGS="-O2 -fno-rtti -fno-exceptions \
-felide-constructors -fno-strength-reduce" \
./configure --prefix=/usr/local/mysql --enable-assembler
gmake
gmake install
cd /usr/local/mysql
bin/mysql_install_db --user=mysql
bin/mysqld_safe &

Be sure that your name resolver setup is correct. Otherwise, you may
experience resolver delays or failures when connecting to *Note
`mysqld': mysqld. Also make sure that the `localhost' entry in the
`/etc/hosts' file is correct. The file should start with a line similar
to this:

127.0.0.1 localhost localhost.your.domain

FreeBSD is known to have a very low default file handle limit. See
*Note not-enough-file-handles::. Start the server by using the
`--open-files-limit' option for *Note `mysqld_safe': mysqld-safe, or
raise the limits for the *Note `mysqld': mysqld. user in
`/etc/login.conf' and rebuild it with `cap_mkdb /etc/login.conf'. Also
be sure that you set the appropriate class for this user in the password
file if you are not using the default (use `chpass mysqld-user-name').
See *Note mysqld-safe::.

FreeBSD limits the size of a process to 512MB, even if you have much
more RAM available on the system. So you may get an error such as this:

Out of memory (Needed 16391 bytes)

In current versions of FreeBSD (at least 4.x and greater), you may
increase this limit by adding the following entries to the
`/boot/loader.conf' file and rebooting the machine (these are not
settings that can be changed at run time with the `sysctl' command):

kern.maxdsiz="1073741824" # 1GB
kern.dfldsiz="1073741824" # 1GB
kern.maxssiz="134217728" # 128MB

For older versions of FreeBSD, you must recompile your kernel to change
the maximum data segment size for a process. In this case, you should
look at the `MAXDSIZ' option in the `LINT' config file for more
information.

If you get problems with the current date in MySQL, setting the `TZ'
variable should help. See *Note environment-variables::.

File: manual.info, Node: netbsd, Next: openbsd, Prev: freebsd, Up: bsd-notes

3.20.4.2 NetBSD Notes
.....................

To compile on NetBSD, you need GNU `make'. Otherwise, the build
process fails when `make' tries to run `lint' on C++ files.

File: manual.info, Node: openbsd, Next: bsdi, Prev: netbsd, Up: bsd-notes

3.20.4.3 OpenBSD 2.5 Notes
..........................

On OpenBSD 2.5, you can compile MySQL with native threads with the
following options:

CFLAGS=-pthread CXXFLAGS=-pthread ./configure --with-mit-threads=no

File: manual.info, Node: bsdi, Next: bsdi3, Prev: openbsd, Up: bsd-notes

3.20.4.4 BSD/OS Version 2.x Notes
.................................

If you get the following error when compiling MySQL, your `ulimit'
value for virtual memory is too low:

item_func.h: In method
`Item_func_ge::Item_func_ge(const Item_func_ge &)':
item_func.h:28: virtual memory exhausted
make[2]: *** [item_func.o] Error 1

Try using `ulimit -v 80000' and run `make' again. If this doesn't work
and you are using `bash', try switching to `csh' or `sh'; some BSDI
users have reported problems with `bash' and `ulimit'.

If you are using `gcc', you may also use have to use the
`--with-low-memory' flag for `configure' to be able to compile
`sql_yacc.cc'.

If you get problems with the current date in MySQL, setting the `TZ'
variable should help. See *Note environment-variables::.

File: manual.info, Node: bsdi3, Next: bsdi4, Prev: bsdi, Up: bsd-notes

3.20.4.5 BSD/OS Version 3.x Notes
.................................

Upgrade to BSD/OS 3.1. If that is not possible, install BSDIpatch
M300-038.

Use the following command when configuring MySQL:

env CXX=shlicc++ CC=shlicc2 \
./configure \
--prefix=/usr/local/mysql \
--localstatedir=/var/mysql \
--without-perl \
--with-unix-socket-path=/var/mysql/mysql.sock

The following is also known to work:

env CC=gcc CXX=gcc CXXFLAGS=-O3 \
./configure \
--prefix=/usr/local/mysql \
--with-unix-socket-path=/var/mysql/mysql.sock

You can change the directory locations if you wish, or just use the
defaults by not specifying any locations.

If you have problems with performance under heavy load, try using the
`--skip-thread-priority' option to *Note `mysqld': mysqld. This runs
all threads with the same priority. On BSDI 3.1, this gives better
performance, at least until BSDI fixes its thread scheduler.

If you get the error `virtual memory exhausted' while compiling, you
should try using `ulimit -v 80000' and running `make' again. If this
doesn't work and you are using `bash', try switching to `csh' or `sh';
some BSDI users have reported problems with `bash' and `ulimit'.

File: manual.info, Node: bsdi4, Prev: bsdi3, Up: bsd-notes

3.20.4.6 BSD/OS Version 4.x Notes
.................................

BSDI 4.x has some thread-related bugs. If you want to use MySQL on
this, you should install all thread-related patches. At least M400-023
should be installed.

On some BSDI 4.x systems, you may get problems with shared libraries.
The symptom is that you can't execute any client programs, for example,
*Note `mysqladmin': mysqladmin. In this case, you need to reconfigure
not to use shared libraries with the `--disable-shared' option to
configure.

Some customers have had problems on BSDI 4.0.1 that the *Note `mysqld':
mysqld. binary after a while can't open tables. This occurs because
some library/system-related bug causes *Note `mysqld': mysqld. to
change current directory without having asked for that to happen.

The fix is to either upgrade MySQL to at least version 3.23.34 or,
after running `configure', remove the line `#define HAVE_REALPATH' from
`config.h' before running `make'.

Note that this means that you can't symbolically link a database
directories to another database directory or symbolic link a table to
another database on BSDI. (Making a symbolic link to another disk is
okay).

File: manual.info, Node: other-unix-notes, Next: os-2, Prev: bsd-notes, Up: operating-system-specific-notes

3.20.5 Other Unix Notes
-----------------------

* Menu:

* hp-ux-10-20:: HP-UX Version 10.20 Notes
* hp-ux-11-x:: HP-UX Version 11.x Notes
* ibm-aix:: IBM-AIX notes
* sunos:: SunOS 4 Notes
* alpha-dec-unix:: Alpha-DEC-UNIX Notes (Tru64)
* alpha-dec-osf1:: Alpha-DEC-OSF/1 Notes
* sgi-irix:: SGI Irix Notes
* sco:: SCO UNIX and OpenServer 5.0.x Notes
* sco-openserver:: SCO OpenServer 6.0.x Notes
* sco-unixware:: SCO UnixWare 7.1.x and OpenUNIX 8.0.0 Notes

File: manual.info, Node: hp-ux-10-20, Next: hp-ux-11-x, Prev: other-unix-notes, Up: other-unix-notes

3.20.5.1 HP-UX Version 10.20 Notes
..................................

If you install MySQL using a binary tarball distribution on HP-UX, you
may run into trouble even before you get the MySQL distribution
unpacked, as the HP-UX `tar' cannot handle long file names. This means
that you may see errors when you try to unpack MySQL.

If this occurs, you must use GNU `tar' (`gtar') to unpack the
distribution.

There are a couple of small problems when compiling MySQL on HP-UX. Use
`gcc' instead of the HP-UX native compiler, because `gcc' produces
better code.

Use `gcc' 2.95 on HP-UX. Do not use high optimization flags (such as
`-O6') because they may not be safe on HP-UX.

The following `configure' line should work with `gcc' 2.95:

CFLAGS="-I/opt/dce/include -fpic" \
CXXFLAGS="-I/opt/dce/include -felide-constructors -fno-exceptions \
-fno-rtti" \
CXX=gcc \
./configure --with-pthread \
--with-named-thread-libs='-ldce' \
--prefix=/usr/local/mysql --disable-shared

The following `configure' line should work with `gcc' 3.1:

CFLAGS="-DHPUX -I/opt/dce/include -O3 -fPIC" CXX=gcc \
CXXFLAGS="-DHPUX -I/opt/dce/include -felide-constructors \
-fno-exceptions -fno-rtti -O3 -fPIC" \
./configure --prefix=/usr/local/mysql \
--with-extra-charsets=complex --enable-thread-safe-client \
--enable-local-infile --with-pthread \
--with-named-thread-libs=-ldce --with-lib-ccflags=-fPIC
--disable-shared

File: manual.info, Node: hp-ux-11-x, Next: ibm-aix, Prev: hp-ux-10-20, Up: other-unix-notes

3.20.5.2 HP-UX Version 11.x Notes
.................................

If this occurs, you must use GNU `tar' (`gtar') to unpack the
distribution.

Because of some critical bugs in the standard HP-UX libraries, you
should install the following patches before trying to run MySQL on
HP-UX 11.0:

PHKL_22840 Streams cumulative
PHNE_22397 ARPA cumulative

This solves the problem of getting `EWOULDBLOCK' from `recv()' and
`EBADF' from `accept()' in threaded applications.

If you are using `gcc' 2.95.1 on an unpatched HP-UX 11.x system, you
may get the following error:

In file included from /usr/include/unistd.h:11,
from ../include/global.h:125,
from mysql_priv.h:15,
from item.cc:19:
/usr/include/sys/unistd.h:184: declaration of C function ...
/usr/include/sys/pthread.h:440: previous declaration ...
In file included from item.h:306,
from mysql_priv.h:158,
from item.cc:19:

The problem is that HP-UX does not define `pthreads_atfork()'
consistently. It has conflicting prototypes in
`/usr/include/sys/unistd.h':184 and `/usr/include/sys/pthread.h':440.

One solution is to copy `/usr/include/sys/unistd.h' into
`mysql/include' and edit `unistd.h' and change it to match the
definition in `pthread.h'. Look for this line:

extern int pthread_atfork(void (*prepare)(), void (*parent)(),
void (*child)());

Change it to look like this:

extern int pthread_atfork(void (*prepare)(void), void (*parent)(void),
void (*child)(void));

After making the change, the following `configure' line should work:

CFLAGS="-fomit-frame-pointer -O3 -fpic" CXX=gcc \
CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti -O3" \
./configure --prefix=/usr/local/mysql --disable-shared

If you are using HP-UX compiler, you can use the following command
(which has been tested with `cc' B.11.11.04):

CC=cc CXX=aCC CFLAGS=+DD64 CXXFLAGS=+DD64 ./configure \
--with-extra-character-set=complex

You can ignore any errors of the following type:

aCC: warning 901: unknown option: `-3': use +help for online
documentation

If you get the following error from `configure', verify that you do not
have the path to the K&R compiler before the path to the HP-UX C and
C++ compiler:

checking for cc option to accept ANSI C... no
configure: error: MySQL requires an ANSI C compiler (and a C++ compiler).
Try gcc. See the Installation chapter in the Reference Manual.

Another reason for not being able to compile is that you didn't define
the `+DD64' flags as just described.

Another possibility for HP-UX 11 is to use the MySQL binaries provided
at `http://dev.mysql.com/downloads/', which we have built and tested
ourselves. We have also received reports that the HP-UX 10.20 binaries
supplied by MySQL can be run successfully on HP-UX 11. If you encounter
problems, you should be sure to check your HP-UX patch level.

File: manual.info, Node: ibm-aix, Next: sunos, Prev: hp-ux-11-x, Up: other-unix-notes

3.20.5.3 IBM-AIX notes
......................

Automatic detection of `xlC' is missing from Autoconf, so a number of
variables need to be set before running `configure'. The following
example uses the IBM compiler:

export CC="xlc_r -ma -O3 -qstrict -qoptimize=3 -qmaxmem=8192 "
export CXX="xlC_r -ma -O3 -qstrict -qoptimize=3 -qmaxmem=8192"
export CFLAGS="-I /usr/local/include"
export LDFLAGS="-L /usr/local/lib"
export CPPFLAGS=$CFLAGS
export CXXFLAGS=$CFLAGS

./configure --prefix=/usr/local \
--localstatedir=/var/mysql \
--sbindir='/usr/local/bin' \
--libexecdir='/usr/local/bin' \
--enable-thread-safe-client \
--enable-large-files

The preceding options are used to compile the MySQL distribution that
can be found at `http://www-frec.bull.com/'.

If you change the `-O3' to `-O2' in the preceding `configure' line, you
must also remove the `-qstrict' option. This is a limitation in the IBM
C compiler.

If you are using `gcc' to compile MySQL, you _must_ use the
`-fno-exceptions' flag, because the exception handling in `gcc' is not
thread-safe! There are also some known problems with IBM's assembler
that may cause it to generate bad code when used with `gcc'.

Use the following `configure' line with `gcc' 2.95 on AIX:

CC="gcc -pipe -mcpu=power -Wa,-many" \
CXX="gcc -pipe -mcpu=power -Wa,-many" \
CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti" \
./configure --prefix=/usr/local/mysql --with-low-memory

The `-Wa,-many' option is necessary for the compile to be successful.
IBM is aware of this problem but is in no hurry to fix it because of
the workaround that is available. We do not know if the
`-fno-exceptions' is required with `gcc' 2.95, but because MySQL
doesn't use exceptions and the option generates faster code, you should
always use it with `gcc'.

If you get a problem with assembler code, try changing the `-mcpu=XXX'
option to match your CPU. Typically `power2', `power', or `powerpc' may
need to be used. Alternatively, you might need to use `604' or `604e'.
We are not positive but suspect that `power' would likely be safe most
of the time, even on a power2 machine.

If you do not know what your CPU is, execute a `uname -m' command. It
produces a string that looks like `000514676700', with a format of
`xxyyyyyymmss' where `xx' and `ss' are always `00', `yyyyyy' is a
unique system ID and `mm' is the ID of the CPU Planar. A chart of these
values can be found at
`http://www16.boulder.ibm.com/pseries/en_US/cmds/aixcmds5/uname.htm'.

This gives you a machine type and a machine model you can use to
determine what type of CPU you have.

If you have problems with threads on AIX 5.3, you should upgrade AIX
5.3 to technology level 7 (5300-07).

If you have problems with signals (MySQL dies unexpectedly under high
load), you may have found an OS bug with threads and signals. In this
case, you can tell MySQL not to use signals by configuring as follows:

CFLAGS=-DDONT_USE_THR_ALARM CXX=gcc \
CXXFLAGS="-felide-constructors -fno-exceptions -fno-rtti \
-DDONT_USE_THR_ALARM" \
./configure --prefix=/usr/local/mysql --with-debug \
--with-low-memory

This doesn't affect the performance of MySQL, but has the side effect
that you can't kill clients that are `sleeping' on a connection with
*Note `mysqladmin kill': mysqladmin. or *Note `mysqladmin shutdown':
mysqladmin. Instead, the client dies when it issues its next command.

On some versions of AIX, linking with `libbind.a' makes
`getservbyname()' dump core. This is an AIX bug and should be reported
to IBM.

For AIX 4.2.1 and `gcc', you have to make the following changes.

After configuring, edit `config.h' and `include/my_config.h' and change
the line that says this:

#define HAVE_SNPRINTF 1

to this:

#undef HAVE_SNPRINTF

And finally, in `mysqld.cc', you need to add a prototype for
`initgroups()'.

#ifdef _AIX41
extern "C" int initgroups(const char *,int);
#endif

For 32-bit binaries, if you need to allocate a lot of memory to the
*Note `mysqld': mysqld. process, it is not enough to just use `ulimit
-d unlimited'. You may also have to modify *Note `mysqld_safe':
mysqld-safe. to add a line something like this:

export LDR_CNTRL='MAXDATA=0x80000000'

You can find more information about using a lot of memory at
`http://publib16.boulder.ibm.com/pseries/en_US/aixprggd/genprogc/lrg_prg_support.htm'.

Users of AIX 4.3 should use `gmake' instead of the `make' utility
included with AIX.

As of AIX 4.1, the C compiler has been unbundled from AIX as a separate
product. `gcc' 3.3.2 can be obtained here:
`ftp://ftp.software.ibm.com/aix/freeSoftware/aixtoolbox/RPMS/ppc/gcc/'

The steps for compiling MySQL on AIX with `gcc' 3.3.2 are similar to
those for using `gcc' 2.95 (in particular, the need to edit `config.h'
and `my_config.h' after running `configure'). However, before running
`configure', you should also patch the `curses.h' file as follows:

/opt/freeware/lib/gcc-lib/powerpc-ibm-aix5.2.0.0/3.3.2/include/curses.h.ORIG
Mon Dec 26 02:17:28 2005
--- /opt/freeware/lib/gcc-lib/powerpc-ibm-aix5.2.0.0/3.3.2/include/curses.h
Mon Dec 26 02:40:13 2005
***************
*** 2023,2029 ****

#endif /* _AIX32_CURSES */
! #if defined(__USE_FIXED_PROTOTYPES__) || defined(__cplusplus) || defined
(__STRICT_ANSI__)
extern int delwin (WINDOW *);
extern int endwin (void);
extern int getcurx (WINDOW *);
--- 2023,2029 ----

#endif /* _AIX32_CURSES */
! #if 0 && (defined(__USE_FIXED_PROTOTYPES__) || defined(__cplusplus)
|| defined
(__STRICT_ANSI__))
extern int delwin (WINDOW *);
extern int endwin (void);
extern int getcurx (WINDOW *);

File: manual.info, Node: sunos, Next: alpha-dec-unix, Prev: ibm-aix, Up: other-unix-notes

3.20.5.4 SunOS 4 Notes
......................

On SunOS 4, MIT-pthreads is needed to compile MySQL. This in turn means
you need GNU `make'.

Some SunOS 4 systems have problems with dynamic libraries and
`libtool'. You can use the following `configure' line to avoid this
problem:

./configure --disable-shared --with-mysqld-ldflags=-all-static

When compiling `readline', you may get warnings about duplicate
defines. These can be ignored.

When compiling *Note `mysqld': mysqld, there are some `implicit
declaration of function' warnings. These can be ignored.

File: manual.info, Node: alpha-dec-unix, Next: alpha-dec-osf1, Prev: sunos, Up: other-unix-notes

3.20.5.5 Alpha-DEC-UNIX Notes (Tru64)
.....................................

If you are using `egcs' 1.1.2 on Digital Unix, you should upgrade to
`gcc' 2.95.2, because `egcs' on DEC has some serious bugs!

When compiling threaded programs under Digital Unix, the documentation
recommends using the `-pthread' option for `cc' and `cxx' and the
`-lmach -lexc' libraries (in addition to `-lpthread'). You should run
`configure' something like this:

CC="cc -pthread" CXX="cxx -pthread -O" \
./configure --with-named-thread-libs="-lpthread -lmach -lexc -lc"

When compiling *Note `mysqld': mysqld, you may see a couple of warnings
like this:

mysqld.cc: In function void handle_connections()':
mysqld.cc:626: passing long unsigned int *' as argument 3 of
accept(int,sockadddr *, int *)'

You can safely ignore these warnings. They occur because `configure'
can detect only errors, not warnings.

If you start the server directly from the command line, you may have
problems with it dying when you log out. (When you log out, your
outstanding processes receive a `SIGHUP' signal.) If so, try starting
the server like this:

nohup mysqld [OPTIONS] &

`nohup' causes the command following it to ignore any `SIGHUP' signal
sent from the terminal. Alternatively, start the server by running
*Note `mysqld_safe': mysqld-safe, which invokes *Note `mysqld': mysqld.
using `nohup' for you. See *Note mysqld-safe::.

If you get a problem when compiling `mysys/get_opt.c', just remove the
`#define _NO_PROTO' line from the start of that file.

If you are using Compaq's CC compiler, the following `configure' line
should work:

CC="cc -pthread"
CFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed \
-speculate all -arch host"
CXX="cxx -pthread"
CXXFLAGS="-O4 -ansi_alias -ansi_args -fast -inline speed \
-speculate all -arch host -noexceptions -nortti"
export CC CFLAGS CXX CXXFLAGS
./configure \
--prefix=/usr/local/mysql \
--with-low-memory \
--enable-large-files \
--enable-shared=yes \
--with-named-thread-libs="-lpthread -lmach -lexc -lc"
gnumake

If you get a problem with `libtool' when compiling with shared
libraries as just shown, when linking *Note `mysql': mysql, you should
be able to get around this by issuing these commands:

cd mysql
/bin/sh ../libtool --mode=link cxx -pthread -O3 -DDBUG_OFF \
-O4 -ansi_alias -ansi_args -fast -inline speed \
-speculate all \ -arch host -DUNDEF_HAVE_GETHOSTBYNAME_R \
-o mysql mysql.o readline.o sql_string.o completion_hash.o \
../readline/libreadline.a -lcurses \
../libmysql/.libs/libmysqlclient.so -lm
cd ..
gnumake
gnumake install
scripts/mysql_install_db

File: manual.info, Node: alpha-dec-osf1, Next: sgi-irix, Prev: alpha-dec-unix, Up: other-unix-notes

3.20.5.6 Alpha-DEC-OSF/1 Notes
..............................

If you have problems compiling and have DEC `CC' and `gcc' installed,
try running `configure' like this:

CC=cc CFLAGS=-O CXX=gcc CXXFLAGS=-O3 \
./configure --prefix=/usr/local/mysql

If you get problems with the `c_asm.h' file, you can create and use a
'dummy' `c_asm.h' file with:

touch include/c_asm.h
CC=gcc CFLAGS=-I./include \
CXX=gcc CXXFLAGS=-O3 \
./configure --prefix=/usr/local/mysql

Note that the following problems with the `ld' program can be fixed by
downloading the latest DEC (Compaq) patch kit from:
`http://ftp.support.compaq.com/public/unix/'.

On OSF/1 V4.0D and compiler "DEC C V5.6-071 on Digital Unix V4.0 (Rev.
878)," the compiler had some strange behavior (undefined `asm' symbols).
`/bin/ld' also appears to be broken (problems with `_exit undefined'
errors occurring while linking *Note `mysqld': mysqld.). On this
system, we have managed to compile MySQL with the following `configure'
line, after replacing `/bin/ld' with the version from OSF 4.0C:

CC=gcc CXX=gcc CXXFLAGS=-O3 ./configure --prefix=/usr/local/mysql

With the Digital compiler "C++ V6.1-029," the following should work:

CC=cc -pthread
CFLAGS=-O4 -ansi_alias -ansi_args -fast -inline speed \
-speculate all -arch host
CXX=cxx -pthread
CXXFLAGS=-O4 -ansi_alias -ansi_args -fast -inline speed \
-speculate all -arch host -noexceptions -nortti
export CC CFLAGS CXX CXXFLAGS
./configure --prefix=/usr/mysql/mysql \
--with-mysqld-ldflags=-all-static --disable-shared \
--with-named-thread-libs="-lmach -lexc -lc"

In some versions of OSF/1, the `alloca()' function is broken. Fix this
by removing the line in `config.h' that defines `'HAVE_ALLOCA''.

The `alloca()' function also may have an incorrect prototype in
`/usr/include/alloca.h'. This warning resulting from this can be
ignored.

`configure' uses the following thread libraries automatically:
`--with-named-thread-libs="-lpthread -lmach -lexc -lc"'.

When using `gcc', you can also try running `configure' like this:

CFLAGS=-D_PTHREAD_USE_D4 CXX=gcc CXXFLAGS=-O3 ./configure ...

CFLAGS=-DDONT_USE_THR_ALARM \
CXXFLAGS=-DDONT_USE_THR_ALARM \
./configure ...

This does not affect the performance of MySQL, but has the side effect
that you can't kill clients that are `sleeping' on a connection with
*Note `mysqladmin kill': mysqladmin. or *Note `mysqladmin shutdown':
mysqladmin. Instead, the client dies when it issues its next command.

With `gcc' 2.95.2, you may encounter the following compile error:

sql_acl.cc:1456: Internal compiler error in `scan_region',
at except.c:2566
Please submit a full bug report.

To fix this, you should change to the `sql' directory and do a
cut-and-paste of the last `gcc' line, but change `-O3' to `-O0' (or add
`-O0' immediately after `gcc' if you do not have any `-O' option on
your compile line). After this is done, you can just change back to the
top-level directory and run `make' again.

File: manual.info, Node: sgi-irix, Next: sco, Prev: alpha-dec-osf1, Up: other-unix-notes

3.20.5.7 SGI Irix Notes
.......................

As of MySQL 5.0, we do not provide binaries for Irix any more.

If you are using Irix 6.5.3 or newer, *Note `mysqld': mysqld. is able
to create threads only if you run it as a user that has `CAP_SCHED_MGT'
privileges (such as `root') or give the *Note `mysqld': mysqld. server
this privilege with the following shell command:

chcap "CAP_SCHED_MGT+epi" /opt/mysql/libexec/mysqld

You may have to undefine some symbols in `config.h' after running
`configure' and before compiling.

In some Irix implementations, the `alloca()' function is broken. If the
*Note `mysqld': mysqld. server dies on some *Note `SELECT': select.
statements, remove the lines from `config.h' that define `HAVE_ALLOC'
and `HAVE_ALLOCA_H'. If *Note `mysqladmin create': mysqladmin. doesn't
work, remove the line from `config.h' that defines `HAVE_READDIR_R'.
You may have to remove the `HAVE_TERM_H' line as well.

SGI recommends that you install all the patches on this page as a set:
`http://support.sgi.com/surfzone/patches/patchset/6.2_indigo.rps.html'

At the very minimum, you should install the latest kernel rollup, the
latest `rld' rollup, and the latest `libc' rollup.

You definitely need all the POSIX patches on this page, for pthreads
support:

`http://support.sgi.com/surfzone/patches/patchset/6.2_posix.rps.html'

If you get the something like the following error when compiling
`mysql.cc':

"/usr/include/curses.h", line 82: error(1084):
invalid combination of type

Type the following in the top-level directory of your MySQL source tree:

extra/replace bool curses_bool < /usr/include/curses.h > include/curses.h
make

There have also been reports of scheduling problems. If only one thread
is running, performance is slow. Avoid this by starting another client.
This may lead to a two-to-tenfold increase in execution speed
thereafter for the other thread. This is a poorly understood problem
with Irix threads; you may have to improvise to find solutions until
this can be fixed.

If you are compiling with `gcc', you can use the following `configure'
command:

CC=gcc CXX=gcc CXXFLAGS=-O3 \
./configure --prefix=/usr/local/mysql --enable-thread-safe-client \
--with-named-thread-libs=-lpthread

On Irix 6.5.11 with native Irix C and C++ compilers ver. 7.3.1.2, the
following is reported to work

CC=cc CXX=CC CFLAGS='-O3 -n32 -TARG:platform=IP22 -I/usr/local/include \
-L/usr/local/lib' CXXFLAGS='-O3 -n32 -TARG:platform=IP22 \
-I/usr/local/include -L/usr/local/lib' \
./configure --prefix=/usr/local/mysql --with-innodb --with-berkeley-db \
--with-libwrap=/usr/local \
--with-named-curses-libs=/usr/local/lib/libncurses.a

File: manual.info, Node: sco, Next: sco-openserver, Prev: sgi-irix, Up: other-unix-notes

3.20.5.8 SCO UNIX and OpenServer 5.0.x Notes
............................................

The current port is tested only on `sco3.2v5.0.5', `sco3.2v5.0.6', and
`sco3.2v5.0.7' systems. There has also been progress on a port to
`sco3.2v4.2'. Open Server 5.0.8 (Legend) has native threads and permits
files greater than 2GB. The current maximum file size is 2GB.

We have been able to compile MySQL with the following `configure'
command on OpenServer with `gcc' 2.95.3.

CC=gcc CFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
CXX=gcc CXXFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
./configure --prefix=/usr/local/mysql \
--enable-thread-safe-client --with-innodb \
--with-openssl --with-vio --with-extra-charsets=complex

`gcc' is available at
`ftp://ftp.sco.com/pub/openserver5/opensrc/gnutools-5.0.7Kj'.

This development system requires the OpenServer Execution Environment
Supplement oss646B on OpenServer 5.0.6 and oss656B and the OpenSource
libraries found in gwxlibs. All OpenSource tools are in the `opensrc'
directory. They are available at
`ftp://ftp.sco.com/pub/openserver5/opensrc/'.

Use the latest production release of MySQL.

SCO provides operating system patches at
`ftp://ftp.sco.com/pub/openserver5' for OpenServer 5.0.[0-6] and
`ftp://ftp.sco.com/pub/openserverv5/507' for OpenServer 5.0.7.

SCO provides information about security fixes at
`ftp://ftp.sco.com/pub/security/OpenServer' for OpenServer 5.0.x.

The maximum file size on an OpenServer 5.0.x system is 2GB.

The total memory which can be allocated for streams buffers, clists,
and lock records cannot exceed 60MB on OpenServer 5.0.x.

Streams buffers are allocated in units of 4096 byte pages, clists are
70 bytes each, and lock records are 64 bytes each, so:

(NSTRPAGES * 4096) + (NCLIST * 70) + (MAX_FLCKREC * 64) <= 62914560

Follow this procedure to configure the Database Services option. If you
are unsure whether an application requires this, see the documentation
provided with the application.

1. Log in as `root'.

2. Enable the SUDS driver by editing the `/etc/conf/sdevice.d/suds'
file. Change the `N' in the second field to a `Y'.

3. Use `mkdev aio' or the Hardware/Kernel Manager to enable support
for asynchronous I/O and relink the kernel. To enable users to
lock down memory for use with this type of I/O, update the
aiomemlock(F) file. This file should be updated to include the
names of users that can use AIO and the maximum amounts of memory
they can lock down.

4. Many applications use setuid binaries so that you need to specify
only a single user. See the documentation provided with the
application to determine whether this is the case for your
application.

After you complete this process, reboot the system to create a new
kernel incorporating these changes.

By default, the entries in `/etc/conf/cf.d/mtune' are set as follows:

Value Default Min Max
----- ------- --- ---
NBUF 0 24 450000
NHBUF 0 32 524288
NMPBUF 0 12 512
MAX_INODE 0 100 64000
MAX_FILE 0 100 64000
CTBUFSIZE 128 0 256
MAX_PROC 0 50 16000
MAX_REGION 0 500 160000
NCLIST 170 120 16640
MAXUP 100 15 16000
NOFILES 110 60 11000
NHINODE 128 64 8192
NAUTOUP 10 0 60
NGROUPS 8 0 128
BDFLUSHR 30 1 300
MAX_FLCKREC 0 50 16000
PUTBUFSZ 8000 2000 20000
MAXSLICE 100 25 100
ULIMIT 4194303 2048 4194303
* Streams Parameters
NSTREAM 64 1 32768
NSTRPUSH 9 9 9
NMUXLINK 192 1 4096
STRMSGSZ 16384 4096 524288
STRCTLSZ 1024 1024 1024
STRMAXBLK 524288 4096 524288
NSTRPAGES 500 0 8000
STRSPLITFRAC 80 50 100
NLOG 3 3 3
NUMSP 64 1 256
NUMTIM 16 1 8192
NUMTRW 16 1 8192
* Semaphore Parameters
SEMMAP 10 10 8192
SEMMNI 10 10 8192
SEMMNS 60 60 8192
SEMMNU 30 10 8192
SEMMSL 25 25 150
SEMOPM 10 10 1024
SEMUME 10 10 25
SEMVMX 32767 32767 32767
SEMAEM 16384 16384 16384
* Shared Memory Parameters
SHMMAX 524288 131072 2147483647
SHMMIN 1 1 1
SHMMNI 100 100 2000
FILE 0 100 64000
NMOUNT 0 4 256
NPROC 0 50 16000
NREGION 0 500 160000

Set these values as follows:

* `NOFILES' should be 4096 or 2048.

* `MAXUP' should be 2048.

To make changes to the kernel, use the `idtune NAME PARAMETER' command.
`idtune' modifies the `/etc/conf/cf.d/stune' file for you. For example,
to change `SEMMS' to `200', execute this command as `root':

# /etc/conf/bin/idtune SEMMNS 200

Then rebuild and reboot the kernel by issuing this command:

# /etc/conf/bin/idbuild -B && init 6

To tune the system, the proper parameter values to use depend on the
number of users accessing the application or database and size the of
the database (that is, the used buffer pool). The following kernel
parameters can be set with `idtune':

* `SHMMAX' (recommended setting: 128MB) and `SHMSEG' (recommended
setting: 15). These parameters have an influence on the MySQL
database engine to create user buffer pools.

* `NOFILES' and `MAXUP' should be set to at least 2048.

* `MAXPROC' should be set to at least 3000/4000 (depends on number
of users) or more.

* The following formulas are recommended to calculate values for
`SEMMSL', `SEMMNS', and `SEMMNU':

SEMMSL = 13

13 is what has been found to be the best for both Progress and
MySQL.

SEMMNS = SEMMSL * NUMBER OF DB SERVERS TO BE RUN ON THE SYSTEM

Set `SEMMNS' to the value of `SEMMSL' multiplied by the number of
database servers (maximum) that you are running on the system at
one time.

SEMMNU = SEMMNS

Set the value of `SEMMNU' to equal the value of `SEMMNS'. You
could probably set this to 75% of `SEMMNS', but this is a
conservative estimate.

You need to at least install the SCO OpenServer Linker and Application
Development Libraries or the OpenServer Development System to use
`gcc'. You cannot use the GCC Dev system without installing one of
these.

You should get the FSU Pthreads package and install it first. This can
be found at
`http://moss.csc.ncsu.edu/~mueller/ftp/pub/PART/pthreads.tar.gz'. You
can also get a precompiled package from
`ftp://ftp.zenez.com/pub/zenez/prgms/FSU-threads-3.14.tar.gz'.

FSU Pthreads can be compiled with SCO Unix 4.2 with tcpip, or using
OpenServer 3.0 or Open Desktop 3.0 (OS 3.0 ODT 3.0) with the SCO
Development System installed using a good port of GCC 2.5.x. For ODT or
OS 3.0, you need a good port of GCC 2.5.x. There are a lot of problems
without a good port. The port for this product requires the SCO Unix
Development system. Without it, you are missing the libraries and the
linker that is needed. You also need `SCO-3.2v4.2-includes.tar.gz'.
This file contains the changes to the SCO Development include files that
are needed to get MySQL to build. You need to replace the existing
system include files with these modified header files. They can be
obtained from
`ftp://ftp.zenez.com/pub/zenez/prgms/SCO-3.2v4.2-includes.tar.gz'.

To build FSU Pthreads on your system, all you should need to do is run
GNU `make'. The `Makefile' in FSU-threads-3.14.tar.gz is set up to make
FSU-threads.

You can run `./configure' in the `threads/src' directory and select the
SCO OpenServer option. This command copies `Makefile.SCO5' to
`Makefile'. Then run `make'.

To install in the default `/usr/include' directory, log in as `root',
and then `cd' to the `thread/src' directory and run `make install'.

Remember that you must use GNU `make' to build MySQL.

*Note*:

If you do not start *Note `mysqld_safe': mysqld-safe. as `root', you
should get only the default 110 open files per process. *Note `mysqld':
mysqld. writes a note about this in the log file.

With SCO 3.2V4.2, you should use FSU Pthreads version 3.14 or newer.
The following `configure' command should work:

CFLAGS="-D_XOPEN_XPG4" CXX=gcc CXXFLAGS="-D_XOPEN_XPG4" \
./configure \
--prefix=/usr/local/mysql \
--with-named-thread-libs="-lgthreads -lsocket -lgen -lgthreads" \
--with-named-curses-libs="-lcurses"

You may have problems with some include files. In this case, you can
find new SCO-specific include files at
`ftp://ftp.zenez.com/pub/zenez/prgms/SCO-3.2v4.2-includes.tar.gz'.

You should unpack this file in the `include' directory of your MySQL
source tree.

SCO development notes:

* MySQL should automatically detect FSU Pthreads and link *Note
`mysqld': mysqld. with `-lgthreads -lsocket -lgthreads'.

* The SCO development libraries are re-entrant in FSU Pthreads. SCO
claims that its library functions are re-entrant, so they must be
re-entrant with FSU Pthreads. FSU Pthreads on OpenServer tries to
use the SCO scheme to make re-entrant libraries.

* FSU Pthreads (at least the version at `ftp://ftp.zenez.com') comes
linked with GNU `malloc'. If you encounter problems with memory
usage, make sure that `gmalloc.o' is included in `libgthreads.a'
and `libgthreads.so'.

* In FSU Pthreads, the following system calls are pthreads-aware:
`read()', `write()', `getmsg()', `connect()', `accept(),'
`select()', and `wait()'.

* The CSSA-2001-SCO.35.2 (the patch is listed in custom as
erg711905-dscr_remap security patch (version 2.0.0)) breaks FSU
threads and makes *Note `mysqld': mysqld. unstable. You have to
remove this one if you want to run *Note `mysqld': mysqld. on an
OpenServer 5.0.6 machine.

* If you use SCO OpenServer 5, you may need to recompile FSU
pthreads with `-DDRAFT7' in `CFLAGS'. Otherwise, `InnoDB' may hang
at a *Note `mysqld': mysqld. startup.

* SCO provides operating system patches at
`ftp://ftp.sco.com/pub/openserver5' for OpenServer 5.0.x.

* SCO provides security fixes and `libsocket.so.2' at
`ftp://ftp.sco.com/pub/security/OpenServer' and
`ftp://ftp.sco.com/pub/security/sse' for OpenServer 5.0.x.

* Pre-OSR506 security fixes. Also, the `telnetd' fix at
`ftp://stage.caldera.com/pub/security/openserver/' or
`ftp://stage.caldera.com/pub/security/openserver/CSSA-2001-SCO.10/'
as both `libsocket.so.2' and `libresolv.so.1' with instructions for
installing on pre-OSR506 systems.

It is probably a good idea to install these patches before trying
to compile/use MySQL.

Beginning with Legend/OpenServer 6.0.0, there are native threads and no
2GB file size limit.

File: manual.info, Node: sco-openserver, Next: sco-unixware, Prev: sco, Up: other-unix-notes

3.20.5.9 SCO OpenServer 6.0.x Notes
...................................

OpenServer 6 includes these key improvements:

* Larger file support up to 1 TB

* Multiprocessor support increased from 4 to 32 processors

* Increased memory support up to 64GB

* Extending the power of UnixWare into OpenServer 6

* Dramatic performance improvement

OpenServer 6.0.0 commands are organized as follows:

* `/bin' is for commands that behave exactly the same as on
OpenServer 5.0.x.

* `/u95/bin' is for commands that have better standards conformance,
for example Large File System (LFS) support.

* `/udk/bin' is for commands that behave the same as on UnixWare
7.1.4. The default is for the LFS support.

The following is a guide to setting `PATH' on OpenServer 6. If the user
wants the traditional OpenServer 5.0.x then `PATH' should be `/bin'
first. If the user wants LFS support, the path should be
`/u95/bin:/bin'. If the user wants UnixWare 7 support first, the path
would be `/udk/bin:/u95/bin:/bin:'.

Use the latest production release of MySQL. Should you choose to use an
older release of MySQL on OpenServer 6.0.x, you must use a version of
MySQL at least as recent as 3.22.13 to get fixes for some portability
and OS problems.

MySQL distribution files with names of the following form are `tar'
archives of media are tar archives of media images suitable for
installation with the SCO Software Manager (`/etc/custom') on SCO
OpenServer 6:

mysql-PRODUCT-5.0.93-sco-osr6-i686.VOLS.tar

A distribution where PRODUCT is `pro-cert' is the Commercially licensed
MySQL Pro Certified server. A distribution where PRODUCT is
`pro-gpl-cert' is the MySQL Pro Certified server licensed under the
terms of the General Public License (GPL).

Select whichever distribution you wish to install and, after download,
extract the `tar' archive into an empty directory. For example:

shell> mkdir /tmp/mysql-pro
shell> cd /tmp/mysql-pro
shell> tar xf /tmp/mysql-pro-cert-5.0.93-sco-osr6-i686.VOLS.tar

Prior to installation, back up your data in accordance with the
procedures outlined in *Note upgrading::.

Remove any previously installed `pkgadd' version of MySQL:

shell> pkginfo mysql 2>&1 > /dev/null && pkgrm mysql

Install MySQL Pro from media images using the SCO Software Manager:

shell> /etc/custom -p SCO:MySQL -i -z /tmp/mysql-pro

Alternatively, the SCO Software Manager can be displayed graphically by
clicking the `Software Manager' icon on the desktop, selecting
`Software -> Install New', selecting the host, selecting `Media Images'
for the Media Device, and entering `/tmp/mysql-pro' as the Image
Directory.

After installation, run `mkdev mysql' as the `root' user to configure
your newly installed MySQL Pro Certified server.

*Note*:

The installation procedure for VOLS packages does not create the
`mysql' user and group that the package uses by default. You should
either create the `mysql' user and group, or else select a different
user and group using an option in `mkdev mysql'.

If you wish to configure your MySQL Pro server to interface with the
Apache Web server using PHP, download and install the PHP update from
SCO at `ftp://ftp.sco.com/pub/updates/OpenServer/SCOSA-2006.17/'.

We have been able to compile MySQL with the following `configure'
command on OpenServer 6.0.x:

CC=cc CFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
CXX=CC CXXFLAGS="-D_FILE_OFFSET_BITS=64 -O3" \
./configure --prefix=/usr/local/mysql \
--enable-thread-safe-client --with-berkeley-db \
--with-extra-charsets=complex \
--build=i686-unknown-sysv5SCO_SV6.0.0

If you use `gcc', you must use `gcc' 2.95.3 or newer.

CC=gcc CXX=g++ ... ./configure ...

The version of Berkeley DB that comes with either UnixWare 7.1.4 or
OpenServer 6.0.0 is not used when building MySQL. MySQL instead uses
its own version of Berkeley DB. The `configure' command needs to build
both a static and a dynamic library in `SRC_DIRECTORY/bdb/build_unix/',
but it does not with MySQL's own `BDB' version. The workaround is as
follows.

1. Configure as normal for MySQL.

2. `cd bdb/build_unix/'

3. `cp -p Makefile Makefile.sav'

4. Use same options and run `../dist/configure'.

5. Run `gmake'.

6. `cp -p Makefile.sav Makefile'

7. Change location to the top source directory and run `gmake'.

This enables both the shared and dynamic libraries to be made and work.

SCO provides OpenServer 6 operating system patches at
`ftp://ftp.sco.com/pub/openserver6'.

SCO provides information about security fixes at
`ftp://ftp.sco.com/pub/security/OpenServer'.

By default, the maximum file size on a OpenServer 6.0.0 system is 1TB.
Some operating system utilities have a limitation of 2GB. The maximum
possible file size on UnixWare 7 is 1TB with VXFS or HTFS.

OpenServer 6 can be configured for large file support (file sizes
greater than 2GB) by tuning the UNIX kernel.

By default, the entries in `/etc/conf/cf.d/mtune' are set as follows:

Value Default Min Max
----- ------- --- ---
SVMMLIM 0x9000000 0x1000000 0x7FFFFFFF
HVMMLIM 0x9000000 0x1000000 0x7FFFFFFF

To make changes to the kernel, use the `idtune NAME PARAMETER' command.
`idtune' modifies the `/etc/conf/cf.d/stune' file for you. To set the
kernel values, execute the following commands as `root':

# /etc/conf/bin/idtune SDATLIM 0x7FFFFFFF
# /etc/conf/bin/idtune HDATLIM 0x7FFFFFFF
# /etc/conf/bin/idtune SVMMLIM 0x7FFFFFFF
# /etc/conf/bin/idtune HVMMLIM 0x7FFFFFFF
# /etc/conf/bin/idtune SFNOLIM 2048
# /etc/conf/bin/idtune HFNOLIM 2048

Then rebuild and reboot the kernel by issuing this command:

# /etc/conf/bin/idbuild -B && init 6

* `SHMMAX' (recommended setting: 128MB) and `SHMSEG' (recommended
setting: 15). These parameters have an influence on the MySQL
database engine to create user buffer pools.

* `SFNOLIM' and `HFNOLIM' should be at maximum 2048.

* `NPROC' should be set to at least 3000/4000 (depends on number of
users).

* The following formulas are recommended to calculate values for
`SEMMSL', `SEMMNS', and `SEMMNU':

SEMMSL = 13

13 is what has been found to be the best for both Progress and
MySQL.

SEMMNS = SEMMSL * NUMBER OF DB SERVERS TO BE RUN ON THE SYSTEM

Set `SEMMNS' to the value of `SEMMSL' multiplied by the number of
database servers (maximum) that you are running on the system at
one time.

SEMMNU = SEMMNS

Set the value of `SEMMNU' to equal the value of `SEMMNS'. You
could probably set this to 75% of `SEMMNS', but this is a
conservative estimate.

File: manual.info, Node: sco-unixware, Prev: sco-openserver, Up: other-unix-notes

3.20.5.10 SCO UnixWare 7.1.x and OpenUNIX 8.0.0 Notes
.....................................................

Use the latest production release of MySQL. Should you choose to use an
older release of MySQL on UnixWare 7.1.x, you must use a version of
MySQL at least as recent as 3.22.13 to get fixes for some portability
and OS problems.

We have been able to compile MySQL with the following `configure'
command on UnixWare 7.1.x:

CC="cc" CFLAGS="-I/usr/local/include" \
CXX="CC" CXXFLAGS="-I/usr/local/include" \
./configure --prefix=/usr/local/mysql \
--enable-thread-safe-client --with-berkeley-db=./bdb \
--with-innodb --with-openssl --with-extra-charsets=complex

If you want to use `gcc', you must use `gcc' 2.95.3 or newer.

CC=gcc CXX=g++ ... ./configure ...

1. Configure as normal for MySQL.

2. `cd bdb/build_unix/'

3. `cp -p Makefile Makefile.sav'

4. Use same options and run `../dist/configure'.

5. Run `gmake'.

6. `cp -p Makefile.sav Makefile'

7. Change to top source directory and run `gmake'.

This enables both the shared and dynamic libraries to be made and work.

SCO provides operating system patches at
`ftp://ftp.sco.com/pub/unixware7' for UnixWare 7.1.1,
`ftp://ftp.sco.com/pub/unixware7/713/' for UnixWare 7.1.3,
`ftp://ftp.sco.com/pub/unixware7/714/' for UnixWare 7.1.4, and
`ftp://ftp.sco.com/pub/openunix8' for OpenUNIX 8.0.0.

SCO provides information about security fixes at
`ftp://ftp.sco.com/pub/security/OpenUNIX' for OpenUNIX and
`ftp://ftp.sco.com/pub/security/UnixWare' for UnixWare.

The UnixWare 7 file size limit is 1 TB with VXFS. Some OS utilities
have a limitation of 2GB.

On UnixWare 7.1.4 you do not need to do anything to get large file
support, but to enable large file support on prior versions of UnixWare
7.1.x, run `fsadm'.

# fsadm -Fvxfs -o largefiles /
# fsadm / * Note
# ulimit unlimited
# /etc/conf/bin/idtune SFSZLIM 0x7FFFFFFF ** Note
# /etc/conf/bin/idtune HFSZLIM 0x7FFFFFFF ** Note
# /etc/conf/bin/idbuild -B

* This should report "largefiles".
** 0x7FFFFFFF represents infinity for these values.

Reboot the system using `shutdown'.

By default, the entries in `/etc/conf/cf.d/mtune' are set as follows:

Value Default Min Max
----- ------- --- ---
SVMMLIM 0x9000000 0x1000000 0x7FFFFFFF
HVMMLIM 0x9000000 0x1000000 0x7FFFFFFF

To make changes to the kernel, use the `idtune NAME PARAMETER' command.
`idtune' modifies the `/etc/conf/cf.d/stune' file for you. To set the
kernel values, execute the following commands as `root':

Then rebuild and reboot the kernel by issuing this command:

# /etc/conf/bin/idbuild -B && init 6

* `SHMMAX' (recommended setting: 128MB) and `SHMSEG' (recommended
setting: 15). These parameters have an influence on the MySQL
database engine to create user buffer pools.

* `SFNOLIM' and `HFNOLIM' should be at maximum 2048.

* `NPROC' should be set to at least 3000/4000 (depends on number of
users).

* The following formulas are recommended to calculate values for
`SEMMSL', `SEMMNS', and `SEMMNU':

SEMMSL = 13

13 is what has been found to be the best for both Progress and
MySQL.

SEMMNS = SEMMSL * NUMBER OF DB SERVERS TO BE RUN ON THE SYSTEM

Set `SEMMNS' to the value of `SEMMSL' multiplied by the number of
database servers (maximum) that you are running on the system at
one time.

SEMMNU = SEMMNS

Set the value of `SEMMNU' to equal the value of `SEMMNS'. You
could probably set this to 75% of `SEMMNS', but this is a
conservative estimate.

File: manual.info, Node: os-2, Prev: other-unix-notes, Up: operating-system-specific-notes

3.20.6 OS/2 Notes
-----------------

*Note*:

We no longer test builds on OS/2. The notes in this section are
provided for your information but may not work on your system.

MySQL uses quite a few open files. Because of this, you should add
something like the following to your `CONFIG.SYS' file:

SET EMXOPT=-c -n -h1024

If you do not do this, you may encounter the following error:

File 'XXXX' not found (Errcode: 24)

When using MySQL with OS/2 Warp 3, FixPack 29 or above is required.
With OS/2 Warp 4, FixPack 4 or above is required. This is a requirement
of the Pthreads library. MySQL must be installed on a partition with a
type that supports long file names, such as HPFS, FAT32, and so on.

The `INSTALL.CMD' script must be run from OS/2's own `CMD.EXE' and may
not work with replacement shells such as `4OS2.EXE'.

The `scripts/mysql-install-db' script has been renamed. It is called
`install.cmd' and is a REXX script, which sets up the default MySQL
security settings and creates the WorkPlace Shell icons for MySQL.

Dynamic module support is compiled in but not fully tested. Dynamic
modules should be compiled using the Pthreads runtime library.

gcc -Zdll -Zmt -Zcrtdll=pthrdrtl -I../include -I../regex -I.. \
-o example udf_example.c -L../lib -lmysqlclient udf_example.def
mv example.dll example.udf

*Note*:

Due to limitations in OS/2, UDF module name stems must not exceed eight
characters. Modules are stored in the `/mysql2/udf' directory; the
`safe-mysqld.cmd' script puts this directory in the `BEGINLIBPATH'
environment variable. When using UDF modules, specified extensions are
ignored--it is assumed to be `.udf'. For example, in Unix, the shared
module might be named `example.so' and you would load a function from
it like this:

mysql> CREATE FUNCTION metaphon RETURNS STRING SONAME 'example.so';

In OS/2, the module would be named `example.udf', but you would not
specify the module extension:

mysql> CREATE FUNCTION metaphon RETURNS STRING SONAME 'example';

File: manual.info, Node: environment-variables, Next: perl-support, Prev: operating-system-specific-notes, Up: installing

3.21 Environment Variables
==========================

This section lists all the environment variables that are used directly
or indirectly by MySQL. Most of these can also be found in other places
in this manual.

Note that any options on the command line take precedence over values
specified in option files and environment variables, and values in
option files take precedence over values in environment variables.

In many cases, it is preferable to use an option file instead of
environment variables to modify the behavior of MySQL. See *Note
option-files::.

Variable Description
`CXX' The name of your C++ compiler (for running
`configure').
`CC' The name of your C compiler (for running `configure').
`CFLAGS' Flags for your C compiler (for running `configure').
`CXXFLAGS' Flags for your C++ compiler (for running `configure').
`DBI_USER' The default user name for Perl DBI.
`DBI_TRACE' Trace options for Perl DBI.
`HOME' The default path for the *Note `mysql': mysql.
history file is `$HOME/.mysql_history'.
`LD_RUN_PATH' Used to specify the location of `libmysqlclient.so'.
`MYSQL_DEBUG' Debug trace options when debugging.
`MYSQL_GROUP_SUFFIX'Option group suffix value (like specifying
`--defaults-group-suffix').
`MYSQL_HISTFILE' The path to the *Note `mysql': mysql. history file.
If this variable is set, its value overrides the
default for `$HOME/.mysql_history'.
`MYSQL_HOME' The path to the directory in which the server-specific
`my.cnf' file resides (as of MySQL 5.0.3).
`MYSQL_HOST' The default host name used by the *Note `mysql':
mysql. command-line client.
`MYSQL_PS1' The command prompt to use in the *Note `mysql':
mysql. command-line client.
`MYSQL_PWD' The default password when connecting to *Note
`mysqld': mysqld. Note that using this is insecure.
See *Note password-security-user::.
`MYSQL_TCP_PORT' The default TCP/IP port number.
`MYSQL_UNIX_PORT' The default Unix socket file name; used for
connections to `localhost'.
`PATH' Used by the shell to find MySQL programs.
`TMPDIR' The directory where temporary files are created.
`TZ' This should be set to your local time zone. See *Note
timezone-problems::.
`UMASK' The user-file creation mode when creating files. See
note following table.
`UMASK_DIR' The user-directory creation mode when creating
directories. See note following table.
`USER' The default user name on Windows and NetWare when
connecting to *Note `mysqld': mysqld.

For information about the *Note `mysql': mysql. history file, see *Note
mysql-history-file::.

The `UMASK' and `UMASK_DIR' variables, despite their names, are used as
modes, not masks:

* If `UMASK' is set, *Note `mysqld': mysqld. uses `($UMASK | 0600)'
as the mode for file creation, so that newly created files have a
mode in the range from 0600 to 0666 (all values octal).

* If `UMASK_DIR' is set, *Note `mysqld': mysqld. uses `($UMASK_DIR |
0700)' as the base mode for directory creation, which then is
AND-ed with `~(~$UMASK & 0666)', so that newly created directories
have a mode in the range from 0700 to 0777 (all values octal). The
AND operation may remove read and write permissions from the
directory mode, but not execute permissions.

MySQL assumes that the value for `UMASK' or `UMASK_DIR' is in octal if
it starts with a zero.

File: manual.info, Node: perl-support, Prev: environment-variables, Up: installing

3.22 Perl Installation Notes
============================

* Menu:

* perl-installation:: Installing Perl on Unix
* activestate-perl:: Installing ActiveState Perl on Windows
* perl-support-problems:: Problems Using the Perl `DBI'/`DBD' Interface

The Perl `DBI' module provides a generic interface for database access.
You can write a `DBI' script that works with many different database
engines without change. To use `DBI', you must install the `DBI'
module, as well as a DataBase Driver (DBD) module for each type of
databas server you want to access. For MySQL, this driver is the
`DBD::mysql' module.

Perl, and the `DBD::MySQL' module for `DBI' must be installed if you
want to run the MySQL benchmark scripts; see *Note mysql-benchmarks::.
They are also required for the MySQL Cluster *Note `ndb_size.pl':
mysql-cluster-programs-ndb-size-pl. utility; see *Note
mysql-cluster-programs-ndb-size-pl::.

*Note*:

Perl support is not included with MySQL distributions. You can obtain
the necessary modules from `http://search.cpan.org' for Unix, or by
using the ActiveState `ppm' program on Windows. The following sections
describe how to do this.

The `DBI'/`DBD' interface requires Perl 5.6.0, and 5.6.1 or later is
preferred. DBI _does not work_ if you have an older version of Perl.
You should use `DBD::mysql' 4.009 or higher. Although earlier versions
are available, they do not support the full functionality of MySQL 5.0.

File: manual.info, Node: perl-installation, Next: activestate-perl, Prev: perl-support, Up: perl-support

3.22.1 Installing Perl on Unix
------------------------------

MySQL Perl support requires that you have installed MySQL client
programming support (libraries and header files). Most installation
methods install the necessary files. If you install MySQL from RPM
files on Linux, be sure to install the developer RPM as well. The
client programs are in the client RPM, but client programming support
is in the developer RPM.

The files you need for Perl support can be obtained from the CPAN
(Comprehensive Perl Archive Network) at `http://search.cpan.org'.

The easiest way to install Perl modules on Unix is to use the `CPAN'
module. For example:

shell> perl -MCPAN -e shell
cpan> install DBI
cpan> install DBD::mysql

The `DBD::mysql' installation runs a number of tests. These tests
attempt to connect to the local MySQL server using the default user
name and password. (The default user name is your login name on Unix,
and `ODBC' on Windows. The default password is `no password.') If you
cannot connect to the server with those values (for example, if your
account has a password), the tests fail. You can use `force install
DBD::mysql' to ignore the failed tests.

`DBI' requires the `Data::Dumper' module. It may be installed; if not,
you should install it before installing `DBI'.

It is also possible to download the module distributions in the form of
compressed `tar' archives and build the modules manually. For example,
to unpack and build a DBI distribution, use a procedure such as this:

1. Unpack the distribution into the current directory:

shell> gunzip < DBI-VERSION.tar.gz | tar xvf -

This command creates a directory named `DBI-VERSION'.

2. Change location into the top-level directory of the unpacked
distribution:

shell> cd DBI-VERSION

3. Build the distribution and compile everything:

shell> perl Makefile.PL
shell> make
shell> make test
shell> make install

The `make test' command is important because it verifies that the
module is working. Note that when you run that command during the
`DBD::mysql' installation to exercise the interface code, the MySQL
server must be running or the test fails.

It is a good idea to rebuild and reinstall the `DBD::mysql'
distribution whenever you install a new release of MySQL. This ensures
that the latest versions of the MySQL client libraries are installed
correctly.

If you do not have access rights to install Perl modules in the system
directory or if you want to install local Perl modules, the following
reference may be useful:
`http://servers.digitaldaze.com/extensions/perl/modules.html#modules'

Look under the heading `Installing New Modules that Require Locally
Installed Modules.'

File: manual.info, Node: activestate-perl, Next: perl-support-problems, Prev: perl-installation, Up: perl-support

3.22.2 Installing ActiveState Perl on Windows
---------------------------------------------

On Windows, you should do the following to install the MySQL `DBD'
module with ActiveState Perl:

1. Get ActiveState Perl from
`http://www.activestate.com/Products/ActivePerl/' and install it.

2. Open a console window.

3. If necessary, set the `HTTP_proxy' variable. For example, you
might try a setting like this:

C:\> set HTTP_proxy=my.proxy.com:3128

4. Start the PPM program:

C:\> C:\perl\bin\ppm.pl

5. If you have not previously done so, install `DBI':

ppm> install DBI

6. If this succeeds, run the following command:

ppm> install DBD-mysql

This procedure should work with ActiveState Perl 5.6 or newer.

If you cannot get the procedure to work, you should install the MyODBC
driver instead and connect to the MySQL server through ODBC:

use DBI;
$dbh= DBI->connect("DBI:ODBC:$dsn",$user,$password) ||
die "Got error $DBI::errstr when connecting to $dsn\n";

File: manual.info, Node: perl-support-problems, Prev: activestate-perl, Up: perl-support

3.22.3 Problems Using the Perl `DBI'/`DBD' Interface
----------------------------------------------------

If Perl reports that it cannot find the `../mysql/mysql.so' module, the
problem is probably that Perl cannot locate the `libmysqlclient.so'
shared library. You should be able to fix this problem by one of the
following methods:

* Compile the `DBD::mysql' distribution with `perl Makefile.PL
-static -config' rather than `perl Makefile.PL'.

* Copy `libmysqlclient.so' to the directory where your other shared
libraries are located (probably `/usr/lib' or `/lib').

* Modify the `-L' options used to compile `DBD::mysql' to reflect
the actual location of `libmysqlclient.so'.

* On Linux, you can add the path name of the directory where
`libmysqlclient.so' is located to the `/etc/ld.so.conf' file.

* Add the path name of the directory where `libmysqlclient.so' is
located to the `LD_RUN_PATH' environment variable. Some systems
use `LD_LIBRARY_PATH' instead.

Note that you may also need to modify the `-L' options if there are
other libraries that the linker fails to find. For example, if the
linker cannot find `libc' because it is in `/lib' and the link command
specifies `-L/usr/lib', change the `-L' option to `-L/lib' or add
`-L/lib' to the existing link command.

If you get the following errors from `DBD::mysql', you are probably
using `gcc' (or using an old binary compiled with `gcc'):

/usr/bin/perl: can't resolve symbol '__moddi3'
/usr/bin/perl: can't resolve symbol '__divdi3'

Add `-L/usr/lib/gcc-lib/... -lgcc' to the link command when the
`mysql.so' library gets built (check the output from `make' for
`mysql.so' when you compile the Perl client). The `-L' option should
specify the path name of the directory where `libgcc.a' is located on
your system.

Another cause of this problem may be that Perl and MySQL are not both
compiled with `gcc'. In this case, you can solve the mismatch by
compiling both with `gcc'.

You may see the following error from `DBD::mysql' when you run the
tests:

t/00base............install_driver(mysql) failed:
Can't load '../blib/arch/auto/DBD/mysql/mysql.so' for module DBD::mysql:
../blib/arch/auto/DBD/mysql/mysql.so: undefined symbol:
uncompress at /usr/lib/perl5/5.00503/i586-linux/DynaLoader.pm line 169.

This means that you need to include the `-lz' compression library on
the link line. That can be done by changing the following line in the
file `lib/DBD/mysql/Install.pm':

$sysliblist .= " -lm";

Change that line to:

$sysliblist .= " -lm -lz";

After this, you _must_ run `make realclean' and then proceed with the
installation from the beginning.

If you want to install DBI on SCO, you have to edit the `Makefile' in
DBI-XXX and each subdirectory. Note that the following assumes `gcc'
2.95.2 or newer:

OLD: NEW:
CC = cc CC = gcc
CCCDLFLAGS = -KPIC -W1,-Bexport CCCDLFLAGS = -fpic
CCDLFLAGS = -wl,-Bexport CCDLFLAGS =

LD = ld LD = gcc -G -fpic
LDDLFLAGS = -G -L/usr/local/lib LDDLFLAGS = -L/usr/local/lib
LDFLAGS = -belf -L/usr/local/lib LDFLAGS = -L/usr/local/lib

LD = ld LD = gcc -G -fpic
OPTIMISE = -Od OPTIMISE = -O1

OLD:
CCCFLAGS = -belf -dy -w0 -U M_XENIX -DPERL_SCO5 -I/usr/local/include

NEW:
CCFLAGS = -U M_XENIX -DPERL_SCO5 -I/usr/local/include

These changes are necessary because the Perl dynaloader does not load
the `DBI' modules if they were compiled with `icc' or `cc'.

If you want to use the Perl module on a system that does not support
dynamic linking (such as SCO), you can generate a static version of
Perl that includes `DBI' and `DBD::mysql'. The way this works is that
you generate a version of Perl with the `DBI' code linked in and
install it on top of your current Perl. Then you use that to build a
version of Perl that additionally has the `DBD' code linked in, and
install that.

On SCO, you must have the following environment variables set:

LD_LIBRARY_PATH=/lib:/usr/lib:/usr/local/lib:/usr/progressive/lib

Or:

LD_LIBRARY_PATH=/usr/lib:/lib:/usr/local/lib:/usr/ccs/lib:\
/usr/progressive/lib:/usr/skunk/lib
LIBPATH=/usr/lib:/lib:/usr/local/lib:/usr/ccs/lib:\
/usr/progressive/lib:/usr/skunk/lib
MANPATH=scohelp:/usr/man:/usr/local1/man:/usr/local/man:\
/usr/skunk/man:

First, create a Perl that includes a statically linked `DBI' module by
running these commands in the directory where your `DBI' distribution is
located:

shell> perl Makefile.PL -static -config
shell> make
shell> make install
shell> make perl

Then, you must install the new Perl. The output of `make perl'
indicates the exact `make' command you need to execute to perform the
installation. On SCO, this is `make -f Makefile.aperl inst_perl
MAP_TARGET=perl'.

Next, use the just-created Perl to create another Perl that also
includes a statically linked `DBD::mysql' by running these commands in
the directory where your `DBD::mysql' distribution is located:

shell> perl Makefile.PL -static -config
shell> make
shell> make install
shell> make perl

Finally, you should install this new Perl. Again, the output of `make
perl' indicates the command to use.

File: manual.info, Node: tutorial, Next: programs, Prev: installing, Up: Top

4 Tutorial
**********

* Menu:

* connecting-disconnecting:: Connecting to and Disconnecting from the Server
* entering-queries:: Entering Queries
* database-use:: Creating and Using a Database
* getting-information:: Getting Information About Databases and Tables
* batch-mode:: Using `mysql' in Batch Mode
* examples:: Examples of Common Queries
* apache:: Using MySQL with Apache

This chapter provides a tutorial introduction to MySQL by showing how
to use the *Note `mysql': mysql. client program to create and use a
simple database. *Note `mysql': mysql. (sometimes referred to as the
`terminal monitor' or just `monitor') is an interactive program that
enables you to connect to a MySQL server, run queries, and view the
results. *Note `mysql': mysql. may also be used in batch mode: you
place your queries in a file beforehand, then tell *Note `mysql':
mysql. to execute the contents of the file. Both ways of using *Note
`mysql': mysql. are covered here.

To see a list of options provided by *Note `mysql': mysql, invoke it
with the `--help' option:

shell> mysql --help

This chapter assumes that *Note `mysql': mysql. is installed on your
machine and that a MySQL server is available to which you can connect.
If this is not true, contact your MySQL administrator. (If _you_ are
the administrator, you need to consult the relevant portions of this
manual, such as *Note server-administration::.)

This chapter describes the entire process of setting up and using a
database. If you are interested only in accessing an existing database,
you may want to skip over the sections that describe how to create the
database and the tables it contains.

Because this chapter is tutorial in nature, many details are
necessarily omitted. Consult the relevant sections of the manual for
more information on the topics covered here.

File: manual.info, Node: connecting-disconnecting, Next: entering-queries, Prev: tutorial, Up: tutorial

4.1 Connecting to and Disconnecting from the Server
===================================================

To connect to the server, you will usually need to provide a MySQL user
name when you invoke *Note `mysql': mysql. and, most likely, a
password. If the server runs on a machine other than the one where you
log in, you will also need to specify a host name. Contact your
administrator to find out what connection parameters you should use to
connect (that is, what host, user name, and password to use). Once you
know the proper parameters, you should be able to connect like this:

shell> mysql -h HOST -u USER -p
Enter password: ********

`host' and `user' represent the host name where your MySQL server is
running and the user name of your MySQL account. Substitute appropriate
values for your setup. The `********' represents your password; enter
it when *Note `mysql': mysql. displays the `Enter password:' prompt.

If that works, you should see some introductory information followed by
a `mysql>' prompt:

shell> mysql -h HOST -u USER -p
Enter password: ********
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 25338 to server version: 5.0.93-standard

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

The `mysql>' prompt tells you that *Note `mysql': mysql. is ready for
you to enter commands.

If you are logging in on the same machine that MySQL is running on, you
can omit the host, and simply use the following:

shell> mysql -u USER -p

If, when you attempt to log in, you get an error message such as `ERROR
2002 (HY000): Can't connect to local MySQL server through socket
'/tmp/mysql.sock' (2)', it means that the MySQL server daemon (Unix) or
service (Windows) is not running. Consult the administrator or see the
section of *Note installing:: that is appropriate to your operating
system.

For help with other problems often encountered when trying to log in,
see *Note common-errors::.

Some MySQL installations permit users to connect as the anonymous
(unnamed) user to the server running on the local host. If this is the
case on your machine, you should be able to connect to that server by
invoking *Note `mysql': mysql. without any options:

shell> mysql

After you have connected successfully, you can disconnect any time by
typing `QUIT' (or `\q') at the `mysql>' prompt:

mysql> QUIT
Bye

On Unix, you can also disconnect by pressing Control-D.

Most examples in the following sections assume that you are connected
to the server. They indicate this by the `mysql>' prompt.

File: manual.info, Node: entering-queries, Next: database-use, Prev: connecting-disconnecting, Up: tutorial

4.2 Entering Queries
====================

Make sure that you are connected to the server, as discussed in the
previous section. Doing so does not in itself select any database to
work with, but that is okay. At this point, it is more important to
find out a little about how to issue queries than to jump right in
creating tables, loading data into them, and retrieving data from them.
This section describes the basic principles of entering commands, using
several queries you can try out to familiarize yourself with how *Note
`mysql': mysql. works.

Here is a simple command that asks the server to tell you its version
number and the current date. Type it in as shown here following the
`mysql>' prompt and press Enter:

This query illustrates several things about *Note `mysql': mysql.:

* A command normally consists of an SQL statement followed by a
semicolon. (There are some exceptions where a semicolon may be
omitted. `QUIT', mentioned earlier, is one of them. We'll get to
others later.)

* When you issue a command, *Note `mysql': mysql. sends it to the
server for execution and displays the results, then prints another
`mysql>' prompt to indicate that it is ready for another command.

* *Note `mysql': mysql. displays query output in tabular form (rows
and columns). The first row contains labels for the columns. The
rows following are the query results. Normally, column labels are
the names of the columns you fetch from database tables. If you're
retrieving the value of an expression rather than a table column
(as in the example just shown), *Note `mysql': mysql. labels the
column using the expression itself.

* *Note `mysql': mysql. shows how many rows were returned and how
long the query took to execute, which gives you a rough idea of
server performance. These values are imprecise because they
represent wall clock time (not CPU or machine time), and because
they are affected by factors such as server load and network
latency. (For brevity, the `rows in set' line is sometimes not
shown in the remaining examples in this chapter.)

Keywords may be entered in any lettercase. The following queries are
equivalent:

mysql> SELECT VERSION(), CURRENT_DATE;
mysql> select version(), current_date;
mysql> SeLeCt vErSiOn(), current_DATE;

Here is another query. It demonstrates that you can use *Note `mysql':
mysql. as a simple calculator:

mysql> SELECT SIN(PI()/4), (4+1)*5;
+------------------+---------+
| SIN(PI()/4) | (4+1)*5 |
+------------------+---------+
| 0.70710678118655 | 25 |
+------------------+---------+
1 row in set (0.02 sec)

The queries shown thus far have been relatively short, single-line
statements. You can even enter multiple statements on a single line.
Just end each one with a semicolon:

mysql> SELECT VERSION(); SELECT NOW();
+----------------+
| VERSION() |
+----------------+
| 5.0.7-beta-Max |
+----------------+
1 row in set (0.00 sec)

+---------------------+
| NOW() |
+---------------------+
| 2005-07-11 17:59:36 |
+---------------------+
1 row in set (0.00 sec)

A command need not be given all on a single line, so lengthy commands
that require several lines are not a problem. *Note `mysql': mysql.
determines where your statement ends by looking for the terminating
semicolon, not by looking for the end of the input line. (In other
words, *Note `mysql': mysql. accepts free-format input: it collects
input lines but does not execute them until it sees the semicolon.)

Here is a simple multiple-line statement:

mysql> SELECT
-> USER()
-> ,
-> CURRENT_DATE;
+---------------+--------------+
| USER() | CURRENT_DATE |
+---------------+--------------+
| jon@localhost | 2005-07-11 |
+---------------+--------------+

In this example, notice how the prompt changes from `mysql>' to `->'
after you enter the first line of a multiple-line query. This is how
*Note `mysql': mysql. indicates that it has not yet seen a complete
statement and is waiting for the rest. The prompt is your friend,
because it provides valuable feedback. If you use that feedback, you
can always be aware of what *Note `mysql': mysql. is waiting for.

If you decide you do not want to execute a command that you are in the
process of entering, cancel it by typing `\c':

mysql> SELECT
-> USER()
-> \c
mysql>

Here, too, notice the prompt. It switches back to `mysql>' after you
type `\c', providing feedback to indicate that *Note `mysql': mysql. is
ready for a new command.

The following table shows each of the prompts you may see and
summarizes what they mean about the state that *Note `mysql': mysql. is
in.

Prompt Meaning
`mysql>'Ready for new command.
`->' Waiting for next line of multiple-line command.
`'>' Waiting for next line, waiting for completion of a string
that began with a single quote (``''').
`">' Waiting for next line, waiting for completion of a string
that began with a double quote (``"'').
``>' Waiting for next line, waiting for completion of an
identifier that began with a backtick (```'').
`/*>' Waiting for next line, waiting for completion of a
comment that began with `/*'.

In the MySQL 5.0 series, the `/*>' prompt was implemented in MySQL
5.0.6.

Multiple-line statements commonly occur by accident when you intend to
issue a command on a single line, but forget the terminating semicolon.
In this case, *Note `mysql': mysql. waits for more input:

mysql> SELECT USER()
->

If this happens to you (you think you've entered a statement but the
only response is a `->' prompt), most likely *Note `mysql': mysql. is
waiting for the semicolon. If you don't notice what the prompt is
telling you, you might sit there for a while before realizing what you
need to do. Enter a semicolon to complete the statement, and *Note
`mysql': mysql. executes it:

mysql> SELECT USER()
-> ;
+---------------+
| USER() |
+---------------+
| jon@localhost |
+---------------+

The `'>' and `">' prompts occur during string collection (another way
of saying that MySQL is waiting for completion of a string). In MySQL,
you can write strings surrounded by either ``''' or ``"'' characters
(for example, `'hello'' or `"goodbye"'), and *Note `mysql': mysql. lets
you enter strings that span multiple lines. When you see a `'>' or `">'
prompt, it means that you have entered a line containing a string that
begins with a ``''' or ``"'' quote character, but have not yet entered
the matching quote that terminates the string. This often indicates
that you have inadvertently left out a quote character. For example:

mysql> SELECT * FROM my_table WHERE name = 'Smith AND age < 30;
'>

If you enter this *Note `SELECT': select. statement, then press `Enter'
and wait for the result, nothing happens. Instead of wondering why this
query takes so long, notice the clue provided by the `'>' prompt. It
tells you that *Note `mysql': mysql. expects to see the rest of an
unterminated string. (Do you see the error in the statement? The string
`'Smith' is missing the second single quotation mark.)

At this point, what do you do? The simplest thing is to cancel the
command. However, you cannot just type `\c' in this case, because *Note
`mysql': mysql. interprets it as part of the string that it is
collecting. Instead, enter the closing quote character (so *Note
`mysql': mysql. knows you've finished the string), then type `\c':

mysql> SELECT * FROM my_table WHERE name = 'Smith AND age < 30;
'> '\c
mysql>

The prompt changes back to `mysql>', indicating that *Note `mysql':
mysql. is ready for a new command.

The ``>' prompt is similar to the `'>' and `">' prompts, but indicates
that you have begun but not completed a backtick-quoted identifier.

It is important to know what the `'>', `">', and ``>' prompts signify,
because if you mistakenly enter an unterminated string, any further
lines you type appear to be ignored by *Note `mysql': mysql.--including
a line containing `QUIT'. This can be quite confusing, especially if
you do not know that you need to supply the terminating quote before
you can cancel the current command.

File: manual.info, Node: database-use, Next: getting-information, Prev: entering-queries, Up: tutorial

4.3 Creating and Using a Database
=================================

* Menu:

* creating-database:: Creating and Selecting a Database
* creating-tables:: Creating a Table
* loading-tables:: Loading Data into a Table
* retrieving-data:: Retrieving Information from a Table

Once you know how to enter commands, you are ready to access a database.

Suppose that you have several pets in your home (your menagerie) and
you would like to keep track of various types of information about
them. You can do so by creating tables to hold your data and loading
them with the desired information. Then you can answer different sorts
of questions about your animals by retrieving data from the tables.
This section shows you how to perform the following operations:

* Create a database

* Create a table

* Load data into the table

* Retrieve data from the table in various ways

* Use multiple tables

The menagerie database is simple (deliberately), but it is not
difficult to think of real-world situations in which a similar type of
database might be used. For example, a database like this could be used
by a farmer to keep track of livestock, or by a veterinarian to keep
track of patient records. A menagerie distribution containing some of
the queries and sample data used in the following sections can be
obtained from the MySQL Web site. It is available in both compressed
`tar' file and Zip formats at `http://dev.mysql.com/doc/'.

Use the *Note `SHOW': show. statement to find out what databases
currently exist on the server:

mysql> SHOW DATABASES;
+----------+
| Database |
+----------+
| mysql |
| test |
| tmp |
+----------+

The `mysql' database describes user access privileges. The `test'
database often is available as a workspace for users to try things out.

The list of databases displayed by the statement may be different on
your machine; *Note `SHOW DATABASES': show-databases. does not show
databases that you have no privileges for if you do not have the *Note
`SHOW DATABASES': show-databases. privilege. See *Note
show-databases::.

If the `test' database exists, try to access it:

mysql> USE test
Database changed

*Note `USE': use, like `QUIT', does not require a semicolon. (You can
terminate such statements with a semicolon if you like; it does no
harm.) The *Note `USE': use. statement is special in another way, too:
it must be given on a single line.

You can use the `test' database (if you have access to it) for the
examples that follow, but anything you create in that database can be
removed by anyone else with access to it. For this reason, you should
probably ask your MySQL administrator for permission to use a database
of your own. Suppose that you want to call yours `menagerie'. The
administrator needs to execute a command like this:

mysql> GRANT ALL ON menagerie.* TO 'your_mysql_name'@'your_client_host';

where `your_mysql_name' is the MySQL user name assigned to you and
`your_client_host' is the host from which you connect to the server.

File: manual.info, Node: creating-database, Next: creating-tables, Prev: database-use, Up: database-use

4.3.1 Creating and Selecting a Database
---------------------------------------

If the administrator creates your database for you when setting up your
permissions, you can begin using it. Otherwise, you need to create it
yourself:

mysql> CREATE DATABASE menagerie;

Under Unix, database names are case sensitive (unlike SQL keywords), so
you must always refer to your database as `menagerie', not as
`Menagerie', `MENAGERIE', or some other variant. This is also true for
table names. (Under Windows, this restriction does not apply, although
you must refer to databases and tables using the same lettercase
throughout a given query. However, for a variety of reasons, the
recommended best practice is always to use the same lettercase that was
used when the database was created.)

*Note*:

If you get an error such as `ERROR 1044 (42000): Access denied for user
'monty'@'localhost' to database 'menagerie'' when attempting to create
a database, this means that your user account does not have the
necessary privileges to do so. Discuss this with the administrator or
see *Note privilege-system::.

Creating a database does not select it for use; you must do that
explicitly. To make `menagerie' the current database, use this command:

mysql> USE menagerie
Database changed

Your database needs to be created only once, but you must select it for
use each time you begin a *Note `mysql': mysql. session. You can do
this by issuing a *Note `USE': use. statement as shown in the example.
Alternatively, you can select the database on the command line when you
invoke *Note `mysql': mysql. Just specify its name after any connection
parameters that you might need to provide. For example:

shell> mysql -h HOST -u USER -p menagerie
Enter password: ********

*Important*:

`menagerie' in the command just shown is *not* your password. If you
want to supply your password on the command line after the `-p' option,
you must do so with no intervening space (for example, as
`-pmypassword', not as `-p mypassword'). However, putting your password
on the command line is not recommended, because doing so exposes it to
snooping by other users logged in on your machine.

*Note*:

You can see at any time which database is currently selected using
*Note `SELECT': select. `DATABASE()'.

File: manual.info, Node: creating-tables, Next: loading-tables, Prev: creating-database, Up: database-use

4.3.2 Creating a Table
----------------------

Creating the database is the easy part, but at this point it is empty,
as *Note `SHOW TABLES': show-tables. tells you:

mysql> SHOW TABLES;
Empty set (0.00 sec)

The harder part is deciding what the structure of your database should
be: what tables you need and what columns should be in each of them.

You want a table that contains a record for each of your pets. This
can be called the `pet' table, and it should contain, as a bare
minimum, each animal's name. Because the name by itself is not very
interesting, the table should contain other information. For example,
if more than one person in your family keeps pets, you might want to
list each animal's owner. You might also want to record some basic
descriptive information such as species and sex.

How about age? That might be of interest, but it is not a good thing to
store in a database. Age changes as time passes, which means you'd have
to update your records often. Instead, it is better to store a fixed
value such as date of birth. Then, whenever you need age, you can
calculate it as the difference between the current date and the birth
date. MySQL provides functions for doing date arithmetic, so this is
not difficult. Storing birth date rather than age has other
advantages, too:

* You can use the database for tasks such as generating reminders
for upcoming pet birthdays. (If you think this type of query is
somewhat silly, note that it is the same question you might ask in
the context of a business database to identify clients to whom you
need to send out birthday greetings in the current week or month,
for that computer-assisted personal touch.)

* You can calculate age in relation to dates other than the current
date. For example, if you store death date in the database, you
can easily calculate how old a pet was when it died.

You can probably think of other types of information that would be
useful in the `pet' table, but the ones identified so far are
sufficient: name, owner, species, sex, birth, and death.

Use a *Note `CREATE TABLE': create-table. statement to specify the
layout of your table:

mysql> CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20),
-> species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);

*Note `VARCHAR': char. is a good choice for the `name', `owner', and
`species' columns because the column values vary in length. The lengths
in those column definitions need not all be the same, and need not be
`20'. You can normally pick any length from `1' to `65535', whatever
seems most reasonable to you.

*Note*:

Prior to MySQL 5.0.3, the upper limit was 255.) If you make a poor
choice and it turns out later that you need a longer field, MySQL
provides an *Note `ALTER TABLE': alter-table. statement.

Several types of values can be chosen to represent sex in animal
records, such as `'m'' and `'f'', or perhaps `'male'' and `'female''.
It is simplest to use the single characters `'m'' and `'f''.

The use of the *Note `DATE': datetime. data type for the `birth' and
`death' columns is a fairly obvious choice.

Once you have created a table, *Note `SHOW TABLES': show-tables. should
produce some output:

mysql> SHOW TABLES;
+---------------------+
| Tables in menagerie |
+---------------------+
| pet |
+---------------------+

To verify that your table was created the way you expected, use a *Note
`DESCRIBE': describe. statement:

You can use *Note `DESCRIBE': describe. any time, for example, if you
forget the names of the columns in your table or what types they have.

For more information about MySQL data types, see *Note data-types::.

File: manual.info, Node: loading-tables, Next: retrieving-data, Prev: creating-tables, Up: database-use

4.3.3 Loading Data into a Table
-------------------------------

After creating your table, you need to populate it. The *Note `LOAD
DATA': load-data. and *Note `INSERT': insert. statements are useful for
this.

Suppose that your pet records can be described as shown here. (Observe
that MySQL expects dates in `'YYYY-MM-DD'' format; this may be different
from what you are used to.)

name owner species sex birth death
Fluffy Harold cat f 1993-02-04
Claws Gwen cat m 1994-03-17
Buffy Harold dog f 1989-05-13
Fang Benny dog m 1990-08-27
Bowser Diane dog m 1979-08-31 1995-07-29
Chirpy Gwen bird f 1998-09-11
WhistlerGwen bird 1997-12-09
Slim Benny snake m 1996-04-29

Because you are beginning with an empty table, an easy way to populate
it is to create a text file containing a row for each of your animals,
then load the contents of the file into the table with a single
statement.

You could create a text file `pet.txt' containing one record per line,
with values separated by tabs, and given in the order in which the
columns were listed in the *Note `CREATE TABLE': create-table.
statement. For missing values (such as unknown sexes or death dates for
animals that are still living), you can use `NULL' values. To represent
these in your text file, use `\N' (backslash, capital-N). For example,
the record for Whistler the bird would look like this (where the
whitespace between values is a single tab character):

Whistler Gwen bird \N 1997-12-09 \N

To load the text file `pet.txt' into the `pet' table, use this
statement:

mysql> LOAD DATA LOCAL INFILE '/path/pet.txt' INTO TABLE pet;

If you created the file on Windows with an editor that uses `\r\n' as a
line terminator, you should use this statement instead:

mysql> LOAD DATA LOCAL INFILE '/path/pet.txt' INTO TABLE pet
-> LINES TERMINATED BY '\r\n';

(On an Apple machine running OS X, you would likely want to use `LINES
TERMINATED BY '\r''.)

You can specify the column value separator and end of line marker
explicitly in the *Note `LOAD DATA': load-data. statement if you wish,
but the defaults are tab and linefeed. These are sufficient for the
statement to read the file `pet.txt' properly.

If the statement fails, it is likely that your MySQL installation does
not have local file capability enabled by default. See *Note
load-data-local::, for information on how to change this.

When you want to add new records one at a time, the *Note `INSERT':
insert. statement is useful. In its simplest form, you supply values
for each column, in the order in which the columns were listed in the
*Note `CREATE TABLE': create-table. statement. Suppose that Diane gets
a new hamster named `Puffball.' You could add a new record using an
*Note `INSERT': insert. statement like this:

mysql> INSERT INTO pet
-> VALUES ('Puffball','Diane','hamster','f','1999-03-30',NULL);

String and date values are specified as quoted strings here. Also,
with *Note `INSERT': insert, you can insert `NULL' directly to
represent a missing value. You do not use `\N' like you do with *Note
`LOAD DATA': load-data.

From this example, you should be able to see that there would be a lot
more typing involved to load your records initially using several *Note
`INSERT': insert. statements rather than a single *Note `LOAD DATA':
load-data. statement.

File: manual.info, Node: retrieving-data, Prev: loading-tables, Up: database-use

4.3.4 Retrieving Information from a Table
-----------------------------------------

* Menu:

* selecting-all:: Selecting All Data
* selecting-rows:: Selecting Particular Rows
* selecting-columns:: Selecting Particular Columns
* sorting-rows:: Sorting Rows
* date-calculations:: Date Calculations
* working-with-null:: Working with `NULL' Values
* pattern-matching:: Pattern Matching
* counting-rows:: Counting Rows
* multiple-tables:: Using More Than one Table

The *Note `SELECT': select. statement is used to pull information from
a table. The general form of the statement is:

SELECT WHAT_TO_SELECT
FROM WHICH_TABLE
WHERE CONDITIONS_TO_SATISFY;

WHAT_TO_SELECT indicates what you want to see. This can be a list of
columns, or `*' to indicate `all columns.' WHICH_TABLE indicates the
table from which you want to retrieve data. The `WHERE' clause is
optional. If it is present, CONDITIONS_TO_SATISFY specifies one or more
conditions that rows must satisfy to qualify for retrieval.

File: manual.info, Node: selecting-all, Next: selecting-rows, Prev: retrieving-data, Up: retrieving-data

4.3.4.1 Selecting All Data
..........................

The simplest form of *Note `SELECT': select. retrieves everything from
a table:

mysql> SELECT * FROM pet;
+----------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+----------+--------+---------+------+------------+------------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Fang | Benny | dog | m | 1990-08-27 | NULL |
| Bowser | Diane | dog | m | 1979-08-31 | 1995-07-29 |
| Chirpy | Gwen | bird | f | 1998-09-11 | NULL |
| Whistler | Gwen | bird | NULL | 1997-12-09 | NULL |
| Slim | Benny | snake | m | 1996-04-29 | NULL |
| Puffball | Diane | hamster | f | 1999-03-30 | NULL |
+----------+--------+---------+------+------------+------------+

This form of *Note `SELECT': select. is useful if you want to review
your entire table, for example, after you've just loaded it with your
initial data set. For example, you may happen to think that the birth
date for Bowser doesn't seem quite right. Consulting your original
pedigree papers, you find that the correct birth year should be 1989,
not 1979.

There are at least two ways to fix this:

* Edit the file `pet.txt' to correct the error, then empty the table
and reload it using *Note `DELETE': delete. and *Note `LOAD DATA':
load-data.:

mysql> DELETE FROM pet;
mysql> LOAD DATA LOCAL INFILE 'pet.txt' INTO TABLE pet;

However, if you do this, you must also re-enter the record for
Puffball.

* Fix only the erroneous record with an *Note `UPDATE': update.
statement:

mysql> UPDATE pet SET birth = '1989-08-31' WHERE name = 'Bowser';

The *Note `UPDATE': update. changes only the record in question
and does not require you to reload the table.

File: manual.info, Node: selecting-rows, Next: selecting-columns, Prev: selecting-all, Up: retrieving-data

4.3.4.2 Selecting Particular Rows
.................................

As shown in the preceding section, it is easy to retrieve an entire
table. Just omit the `WHERE' clause from the *Note `SELECT': select.
statement. But typically you don't want to see the entire table,
particularly when it becomes large. Instead, you're usually more
interested in answering a particular question, in which case you specify
some constraints on the information you want. Let's look at some
selection queries in terms of questions about your pets that they
answer.

You can select only particular rows from your table. For example, if
you want to verify the change that you made to Bowser's birth date,
select Bowser's record like this:

mysql> SELECT * FROM pet WHERE name = 'Bowser';
+--------+-------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+--------+-------+---------+------+------------+------------+
| Bowser | Diane | dog | m | 1989-08-31 | 1995-07-29 |
+--------+-------+---------+------+------------+------------+

The output confirms that the year is correctly recorded as 1989, not
1979.

String comparisons normally are case-insensitive, so you can specify
the name as `'bowser'', `'BOWSER'', and so forth. The query result is
the same.

You can specify conditions on any column, not just `name'. For example,
if you want to know which animals were born during or after 1998, test
the `birth' column:

You can combine conditions, for example, to locate female dogs:

The preceding query uses the `AND' logical operator. There is also an
`OR' operator:

`AND' and `OR' may be intermixed, although `AND' has higher precedence
than `OR'. If you use both operators, it is a good idea to use
parentheses to indicate explicitly how conditions should be grouped:

mysql> SELECT * FROM pet WHERE (species = 'cat' AND sex = 'm')
-> OR (species = 'dog' AND sex = 'f');
+-------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+-------+--------+---------+------+------------+-------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+-------+--------+---------+------+------------+-------+

File: manual.info, Node: selecting-columns, Next: sorting-rows, Prev: selecting-rows, Up: retrieving-data

4.3.4.3 Selecting Particular Columns
....................................

If you do not want to see entire rows from your table, just name the
columns in which you are interested, separated by commas. For example,
if you want to know when your animals were born, select the `name' and
`birth' columns:

mysql> SELECT name, birth FROM pet;
+----------+------------+
| name | birth |
+----------+------------+
| Fluffy | 1993-02-04 |
| Claws | 1994-03-17 |
| Buffy | 1989-05-13 |
| Fang | 1990-08-27 |
| Bowser | 1989-08-31 |
| Chirpy | 1998-09-11 |
| Whistler | 1997-12-09 |
| Slim | 1996-04-29 |
| Puffball | 1999-03-30 |
+----------+------------+

To find out who owns pets, use this query:

Notice that the query simply retrieves the `owner' column from each
record, and some of them appear more than once. To minimize the output,
retrieve each unique output record just once by adding the keyword
`DISTINCT':

You can use a `WHERE' clause to combine row selection with column
selection. For example, to get birth dates for dogs and cats only, use
this query:

mysql> SELECT name, species, birth FROM pet
-> WHERE species = 'dog' OR species = 'cat';
+--------+---------+------------+
| name | species | birth |
+--------+---------+------------+
| Fluffy | cat | 1993-02-04 |
| Claws | cat | 1994-03-17 |
| Buffy | dog | 1989-05-13 |
| Fang | dog | 1990-08-27 |
| Bowser | dog | 1989-08-31 |
+--------+---------+------------+

File: manual.info, Node: sorting-rows, Next: date-calculations, Prev: selecting-columns, Up: retrieving-data

4.3.4.4 Sorting Rows
....................

You may have noticed in the preceding examples that the result rows are
displayed in no particular order. It is often easier to examine query
output when the rows are sorted in some meaningful way. To sort a
result, use an `ORDER BY' clause.

Here are animal birthdays, sorted by date:

mysql> SELECT name, birth FROM pet ORDER BY birth;
+----------+------------+
| name | birth |
+----------+------------+
| Buffy | 1989-05-13 |
| Bowser | 1989-08-31 |
| Fang | 1990-08-27 |
| Fluffy | 1993-02-04 |
| Claws | 1994-03-17 |
| Slim | 1996-04-29 |
| Whistler | 1997-12-09 |
| Chirpy | 1998-09-11 |
| Puffball | 1999-03-30 |
+----------+------------+

On character type columns, sorting--like all other comparison
operations--is normally performed in a case-insensitive fashion. This
means that the order is undefined for columns that are identical except
for their case. You can force a case-sensitive sort for a column by
using `BINARY' like so: `ORDER BY BINARY COL_NAME'.

The default sort order is ascending, with smallest values first. To
sort in reverse (descending) order, add the `DESC' keyword to the name
of the column you are sorting by:

mysql> SELECT name, birth FROM pet ORDER BY birth DESC;
+----------+------------+
| name | birth |
+----------+------------+
| Puffball | 1999-03-30 |
| Chirpy | 1998-09-11 |
| Whistler | 1997-12-09 |
| Slim | 1996-04-29 |
| Claws | 1994-03-17 |
| Fluffy | 1993-02-04 |
| Fang | 1990-08-27 |
| Bowser | 1989-08-31 |
| Buffy | 1989-05-13 |
+----------+------------+

You can sort on multiple columns, and you can sort different columns in
different directions. For example, to sort by type of animal in
ascending order, then by birth date within animal type in descending
order (youngest animals first), use the following query:

mysql> SELECT name, species, birth FROM pet
-> ORDER BY species, birth DESC;
+----------+---------+------------+
| name | species | birth |
+----------+---------+------------+
| Chirpy | bird | 1998-09-11 |
| Whistler | bird | 1997-12-09 |
| Claws | cat | 1994-03-17 |
| Fluffy | cat | 1993-02-04 |
| Fang | dog | 1990-08-27 |
| Bowser | dog | 1989-08-31 |
| Buffy | dog | 1989-05-13 |
| Puffball | hamster | 1999-03-30 |
| Slim | snake | 1996-04-29 |
+----------+---------+------------+

The `DESC' keyword applies only to the column name immediately
preceding it (`birth'); it does not affect the `species' column sort
order.

File: manual.info, Node: date-calculations, Next: working-with-null, Prev: sorting-rows, Up: retrieving-data

4.3.4.5 Date Calculations
.........................

MySQL provides several functions that you can use to perform
calculations on dates, for example, to calculate ages or extract parts
of dates.

To determine how many years old each of your pets is, compute the
difference in the year part of the current date and the birth date,
then subtract one if the current date occurs earlier in the calendar
year than the birth date. The following query shows, for each pet, the
birth date, the current date, and the age in years.

mysql> SELECT name, birth, CURDATE(),
-> (YEAR(CURDATE())-YEAR(birth))
-> - (RIGHT(CURDATE(),5)<RIGHT(birth,5))
-> AS age
-> FROM pet;
+----------+------------+------------+------+
| name | birth | CURDATE() | age |
+----------+------------+------------+------+
| Fluffy | 1993-02-04 | 2003-08-19 | 10 |
| Claws | 1994-03-17 | 2003-08-19 | 9 |
| Buffy | 1989-05-13 | 2003-08-19 | 14 |
| Fang | 1990-08-27 | 2003-08-19 | 12 |
| Bowser | 1989-08-31 | 2003-08-19 | 13 |
| Chirpy | 1998-09-11 | 2003-08-19 | 4 |
| Whistler | 1997-12-09 | 2003-08-19 | 5 |
| Slim | 1996-04-29 | 2003-08-19 | 7 |
| Puffball | 1999-03-30 | 2003-08-19 | 4 |
+----------+------------+------------+------+

Here, `YEAR()' pulls out the year part of a date and `RIGHT()' pulls
off the rightmost five characters that represent the `MM-DD' (calendar
year) part of the date. The part of the expression that compares the
`MM-DD' values evaluates to 1 or 0, which adjusts the year difference
down a year if `CURDATE()' occurs earlier in the year than `birth'. The
full expression is somewhat ungainly, so an _alias_ (`age') is used to
make the output column label more meaningful.

The query works, but the result could be scanned more easily if the
rows were presented in some order. This can be done by adding an `ORDER
BY name' clause to sort the output by name:

mysql> SELECT name, birth, CURDATE(),
-> (YEAR(CURDATE())-YEAR(birth))
-> - (RIGHT(CURDATE(),5)<RIGHT(birth,5))
-> AS age
-> FROM pet ORDER BY name;
+----------+------------+------------+------+
| name | birth | CURDATE() | age |
+----------+------------+------------+------+
| Bowser | 1989-08-31 | 2003-08-19 | 13 |
| Buffy | 1989-05-13 | 2003-08-19 | 14 |
| Chirpy | 1998-09-11 | 2003-08-19 | 4 |
| Claws | 1994-03-17 | 2003-08-19 | 9 |
| Fang | 1990-08-27 | 2003-08-19 | 12 |
| Fluffy | 1993-02-04 | 2003-08-19 | 10 |
| Puffball | 1999-03-30 | 2003-08-19 | 4 |
| Slim | 1996-04-29 | 2003-08-19 | 7 |
| Whistler | 1997-12-09 | 2003-08-19 | 5 |
+----------+------------+------------+------+

To sort the output by `age' rather than `name', just use a different
`ORDER BY' clause:

mysql> SELECT name, birth, CURDATE(),
-> (YEAR(CURDATE())-YEAR(birth))
-> - (RIGHT(CURDATE(),5)<RIGHT(birth,5))
-> AS age
-> FROM pet ORDER BY age;
+----------+------------+------------+------+
| name | birth | CURDATE() | age |
+----------+------------+------------+------+
| Chirpy | 1998-09-11 | 2003-08-19 | 4 |
| Puffball | 1999-03-30 | 2003-08-19 | 4 |
| Whistler | 1997-12-09 | 2003-08-19 | 5 |
| Slim | 1996-04-29 | 2003-08-19 | 7 |
| Claws | 1994-03-17 | 2003-08-19 | 9 |
| Fluffy | 1993-02-04 | 2003-08-19 | 10 |
| Fang | 1990-08-27 | 2003-08-19 | 12 |
| Bowser | 1989-08-31 | 2003-08-19 | 13 |
| Buffy | 1989-05-13 | 2003-08-19 | 14 |
+----------+------------+------------+------+

A similar query can be used to determine age at death for animals that
have died. You determine which animals these are by checking whether
the `death' value is `NULL'. Then, for those with non-`NULL' values,
compute the difference between the `death' and `birth' values:

mysql> SELECT name, birth, death,
-> (YEAR(death)-YEAR(birth)) - (RIGHT(death,5)<RIGHT(birth,5))
-> AS age
-> FROM pet WHERE death IS NOT NULL ORDER BY age;
+--------+------------+------------+------+
| name | birth | death | age |
+--------+------------+------------+------+
| Bowser | 1989-08-31 | 1995-07-29 | 5 |
+--------+------------+------------+------+

The query uses `death IS NOT NULL' rather than `death <> NULL' because
`NULL' is a special value that cannot be compared using the usual
comparison operators. This is discussed later. See *Note
working-with-null::.

What if you want to know which animals have birthdays next month? For
this type of calculation, year and day are irrelevant; you simply want
to extract the month part of the `birth' column. MySQL provides several
functions for extracting parts of dates, such as `YEAR()', `MONTH()',
and `DAYOFMONTH()'. `MONTH()' is the appropriate function here. To see
how it works, run a simple query that displays the value of both
`birth' and `MONTH(birth)':

mysql> SELECT name, birth, MONTH(birth) FROM pet;
+----------+------------+--------------+
| name | birth | MONTH(birth) |
+----------+------------+--------------+
| Fluffy | 1993-02-04 | 2 |
| Claws | 1994-03-17 | 3 |
| Buffy | 1989-05-13 | 5 |
| Fang | 1990-08-27 | 8 |
| Bowser | 1989-08-31 | 8 |
| Chirpy | 1998-09-11 | 9 |
| Whistler | 1997-12-09 | 12 |
| Slim | 1996-04-29 | 4 |
| Puffball | 1999-03-30 | 3 |
+----------+------------+--------------+

Finding animals with birthdays in the upcoming month is also simple.
Suppose that the current month is April. Then the month value is `4'
and you can look for animals born in May (month `5') like this:

mysql> SELECT name, birth FROM pet WHERE MONTH(birth) = 5;
+-------+------------+
| name | birth |
+-------+------------+
| Buffy | 1989-05-13 |
+-------+------------+

There is a small complication if the current month is December. You
cannot merely add one to the month number (`12') and look for animals
born in month `13', because there is no such month. Instead, you look
for animals born in January (month `1').

You can write the query so that it works no matter what the current
month is, so that you do not have to use the number for a particular
month. `DATE_ADD()' enables you to add a time interval to a given
date. If you add a month to the value of `CURDATE()', then extract the
month part with `MONTH()', the result produces the month in which to
look for birthdays:

mysql> SELECT name, birth FROM pet
-> WHERE MONTH(birth) = MONTH(DATE_ADD(CURDATE(),INTERVAL 1 MONTH));

A different way to accomplish the same task is to add `1' to get the
next month after the current one after using the modulo function (`MOD')
to wrap the month value to `0' if it is currently `12':

mysql> SELECT name, birth FROM pet
-> WHERE MONTH(birth) = MOD(MONTH(CURDATE()), 12) + 1;

`MONTH()' returns a number between `1' and `12'. And
`MOD(something,12)' returns a number between `0' and `11'. So the
addition has to be after the `MOD()', otherwise we would go from
November (`11') to January (`1').

File: manual.info, Node: working-with-null, Next: pattern-matching, Prev: date-calculations, Up: retrieving-data

4.3.4.6 Working with `NULL' Values
..................................

The `NULL' value can be surprising until you get used to it.
Conceptually, `NULL' means `a missing unknown value' and it is treated
somewhat differently from other values. To test for `NULL', you cannot
use the arithmetic comparison operators such as `=', `<', or `<>'. To
demonstrate this for yourself, try the following query:

Clearly you get no meaningful results from these comparisons. Use the
`IS NULL' and `IS NOT NULL' operators instead:

mysql> SELECT 1 IS NULL, 1 IS NOT NULL;
+-----------+---------------+
| 1 IS NULL | 1 IS NOT NULL |
+-----------+---------------+
| 0 | 1 |
+-----------+---------------+

In MySQL, `0' or `NULL' means false and anything else means true. The
default truth value from a boolean operation is `1'.

This special treatment of `NULL' is why, in the previous section, it
was necessary to determine which animals are no longer alive using
`death IS NOT NULL' instead of `death <> NULL'.

Two `NULL' values are regarded as equal in a `GROUP BY'.

When doing an `ORDER BY', `NULL' values are presented first if you do
`ORDER BY ... ASC' and last if you do `ORDER BY ... DESC'.

A common error when working with `NULL' is to assume that it is not
possible to insert a zero or an empty string into a column defined as
`NOT NULL', but this is not the case. These are in fact values, whereas
`NULL' means `not having a value.' You can test this easily enough by
using `IS [NOT] NULL' as shown:

mysql> SELECT 0 IS NULL, 0 IS NOT NULL, '' IS NULL, '' IS NOT NULL;
+-----------+---------------+------------+----------------+
| 0 IS NULL | 0 IS NOT NULL | '' IS NULL | '' IS NOT NULL |
+-----------+---------------+------------+----------------+
| 0 | 1 | 0 | 1 |
+-----------+---------------+------------+----------------+

Thus it is entirely possible to insert a zero or empty string into a
`NOT NULL' column, as these are in fact `NOT NULL'. See *Note
problems-with-null::.

File: manual.info, Node: pattern-matching, Next: counting-rows, Prev: working-with-null, Up: retrieving-data

4.3.4.7 Pattern Matching
........................

MySQL provides standard SQL pattern matching as well as a form of
pattern matching based on extended regular expressions similar to those
used by Unix utilities such as `vi', `grep', and `sed'.

SQL pattern matching enables you to use ``_'' to match any single
character and ``%'' to match an arbitrary number of characters
(including zero characters). In MySQL, SQL patterns are
case-insensitive by default. Some examples are shown here. You do not
use `=' or `<>' when you use SQL patterns; use the `LIKE' or `NOT LIKE'
comparison operators instead.

To find names beginning with ``b'':

mysql> SELECT * FROM pet WHERE name LIKE 'b%';
+--------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+--------+--------+---------+------+------------+------------+
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Bowser | Diane | dog | m | 1989-08-31 | 1995-07-29 |
+--------+--------+---------+------+------------+------------+

To find names ending with ``fy'':

mysql> SELECT * FROM pet WHERE name LIKE '%fy';
+--------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+--------+--------+---------+------+------------+-------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+--------+--------+---------+------+------------+-------+

To find names containing a ``w'':

mysql> SELECT * FROM pet WHERE name LIKE '%w%';
+----------+-------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+----------+-------+---------+------+------------+------------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Bowser | Diane | dog | m | 1989-08-31 | 1995-07-29 |
| Whistler | Gwen | bird | NULL | 1997-12-09 | NULL |
+----------+-------+---------+------+------------+------------+

To find names containing exactly five characters, use five instances of
the ``_'' pattern character:

mysql> SELECT * FROM pet WHERE name LIKE '_____';
+-------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+-------+--------+---------+------+------------+-------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+-------+--------+---------+------+------------+-------+

The other type of pattern matching provided by MySQL uses extended
regular expressions. When you test for a match for this type of
pattern, use the `REGEXP' and `NOT REGEXP' operators (or `RLIKE' and
`NOT RLIKE', which are synonyms).

The following list describes some characteristics of extended regular
expressions:

* ``.'' matches any single character.

* A character class ``[...]'' matches any character within the
brackets. For example, ``[abc]'' matches ``a'', ``b'', or ``c''.
To name a range of characters, use a dash. ``[a-z]'' matches any
letter, whereas ``[0-9]'' matches any digit.

* ``*'' matches zero or more instances of the thing preceding it.
For example, ``x*'' matches any number of ``x'' characters,
``[0-9]*'' matches any number of digits, and ``.*'' matches any
number of anything.

* A `REGEXP' pattern match succeeds if the pattern matches anywhere
in the value being tested. (This differs from a `LIKE' pattern
match, which succeeds only if the pattern matches the entire
value.)

* To anchor a pattern so that it must match the beginning or end of
the value being tested, use ``^'' at the beginning or ``$'' at the
end of the pattern.

To demonstrate how extended regular expressions work, the `LIKE'
queries shown previously are rewritten here to use `REGEXP'.

To find names beginning with ``b'', use ``^'' to match the beginning of
the name:

mysql> SELECT * FROM pet WHERE name REGEXP '^b';
+--------+--------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+--------+--------+---------+------+------------+------------+
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
| Bowser | Diane | dog | m | 1989-08-31 | 1995-07-29 |
+--------+--------+---------+------+------------+------------+

If you really want to force a `REGEXP' comparison to be case sensitive,
use the `BINARY' keyword to make one of the strings a binary string.
This query matches only lowercase ``b'' at the beginning of a name:

mysql> SELECT * FROM pet WHERE name REGEXP BINARY '^b';

To find names ending with ``fy'', use ``$'' to match the end of the
name:

mysql> SELECT * FROM pet WHERE name REGEXP 'fy$';
+--------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+--------+--------+---------+------+------------+-------+
| Fluffy | Harold | cat | f | 1993-02-04 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+--------+--------+---------+------+------------+-------+

To find names containing a ``w'', use this query:

mysql> SELECT * FROM pet WHERE name REGEXP 'w';
+----------+-------+---------+------+------------+------------+
| name | owner | species | sex | birth | death |
+----------+-------+---------+------+------------+------------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Bowser | Diane | dog | m | 1989-08-31 | 1995-07-29 |
| Whistler | Gwen | bird | NULL | 1997-12-09 | NULL |
+----------+-------+---------+------+------------+------------+

Because a regular expression pattern matches if it occurs anywhere in
the value, it is not necessary in the previous query to put a wildcard
on either side of the pattern to get it to match the entire value like
it would be if you used an SQL pattern.

To find names containing exactly five characters, use ``^'' and ``$''
to match the beginning and end of the name, and five instances of ``.''
in between:

mysql> SELECT * FROM pet WHERE name REGEXP '^.....$';
+-------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+-------+--------+---------+------+------------+-------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+-------+--------+---------+------+------------+-------+

You could also write the previous query using the `{N}'
(`repeat-N-times') operator:

mysql> SELECT * FROM pet WHERE name REGEXP '^.{5}$';
+-------+--------+---------+------+------------+-------+
| name | owner | species | sex | birth | death |
+-------+--------+---------+------+------------+-------+
| Claws | Gwen | cat | m | 1994-03-17 | NULL |
| Buffy | Harold | dog | f | 1989-05-13 | NULL |
+-------+--------+---------+------+------------+-------+

*Note regexp::, provides more information about the syntax for regular
expressions.

File: manual.info, Node: counting-rows, Next: multiple-tables, Prev: pattern-matching, Up: retrieving-data

4.3.4.8 Counting Rows
.....................

Databases are often used to answer the question, `How often does a
certain type of data occur in a table?' For example, you might want to
know how many pets you have, or how many pets each owner has, or you
might want to perform various kinds of census operations on your
animals.

Counting the total number of animals you have is the same question as
`How many rows are in the `pet' table?' because there is one record per
pet. `COUNT(*)' counts the number of rows, so the query to count your
animals looks like this:

mysql> SELECT COUNT(*) FROM pet;
+----------+
| COUNT(*) |
+----------+
| 9 |
+----------+

Earlier, you retrieved the names of the people who owned pets. You can
use `COUNT()' if you want to find out how many pets each owner has:

mysql> SELECT owner, COUNT(*) FROM pet GROUP BY owner;
+--------+----------+
| owner | COUNT(*) |
+--------+----------+
| Benny | 2 |
| Diane | 2 |
| Gwen | 3 |
| Harold | 2 |
+--------+----------+

The preceding query uses `GROUP BY' to group all records for each
`owner'. The use of `COUNT()' in conjunction with `GROUP BY' is useful
for characterizing your data under various groupings. The following
examples show different ways to perform animal census operations.

Number of animals per species:

mysql> SELECT species, COUNT(*) FROM pet GROUP BY species;
+---------+----------+
| species | COUNT(*) |
+---------+----------+
| bird | 2 |
| cat | 2 |
| dog | 3 |
| hamster | 1 |
| snake | 1 |
+---------+----------+

Number of animals per sex:

mysql> SELECT sex, COUNT(*) FROM pet GROUP BY sex;
+------+----------+
| sex | COUNT(*) |
+------+----------+
| NULL | 1 |
| f | 4 |
| m | 4 |
+------+----------+

(In this output, `NULL' indicates that the sex is unknown.)

Number of animals per combination of species and sex:

mysql> SELECT species, sex, COUNT(*) FROM pet GROUP BY species, sex;
+---------+------+----------+
| species | sex | COUNT(*) |
+---------+------+----------+
| bird | NULL | 1 |
| bird | f | 1 |
| cat | f | 1 |
| cat | m | 1 |
| dog | f | 1 |
| dog | m | 2 |
| hamster | f | 1 |
| snake | m | 1 |
+---------+------+----------+

You need not retrieve an entire table when you use `COUNT()'. For
example, the previous query, when performed just on dogs and cats, looks
like this:

mysql> SELECT species, sex, COUNT(*) FROM pet
-> WHERE species = 'dog' OR species = 'cat'
-> GROUP BY species, sex;
+---------+------+----------+
| species | sex | COUNT(*) |
+---------+------+----------+
| cat | f | 1 |
| cat | m | 1 |
| dog | f | 1 |
| dog | m | 2 |
+---------+------+----------+

Or, if you wanted the number of animals per sex only for animals whose
sex is known:

mysql> SELECT species, sex, COUNT(*) FROM pet
-> WHERE sex IS NOT NULL
-> GROUP BY species, sex;
+---------+------+----------+
| species | sex | COUNT(*) |
+---------+------+----------+
| bird | f | 1 |
| cat | f | 1 |
| cat | m | 1 |
| dog | f | 1 |
| dog | m | 2 |
| hamster | f | 1 |
| snake | m | 1 |
+---------+------+----------+

If you name columns to select in addition to the `COUNT()' value, a
`GROUP BY' clause should be present that names those same columns.
Otherwise, the following occurs:

* If the `ONLY_FULL_GROUP_BY' SQL mode is enabled, an error occurs:

mysql> SET sql_mode = 'ONLY_FULL_GROUP_BY';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT owner, COUNT(*) FROM pet;
ERROR 1140 (42000): Mixing of GROUP columns (MIN(),MAX(),COUNT()...)
with no GROUP columns is illegal if there is no GROUP BY clause

* If `ONLY_FULL_GROUP_BY' is not enabled, the query is processed by
treating all rows as a single group, but the value selected for
each named column is indeterminate. The server is free to select
the value from any row:

mysql> SET sql_mode = '';
Query OK, 0 rows affected (0.00 sec)

See also *Note group-by-hidden-columns::.

File: manual.info, Node: multiple-tables, Prev: counting-rows, Up: retrieving-data

4.3.4.9 Using More Than one Table
.................................

The `pet' table keeps track of which pets you have. If you want to
record other information about them, such as events in their lives like
visits to the vet or when litters are born, you need another table.
What should this table look like? It needs to contain the following
information:

* The pet name so that you know which animal each event pertains to.

* A date so that you know when the event occurred.

* A field to describe the event.

* An event type field, if you want to be able to categorize events.

Given these considerations, the *Note `CREATE TABLE': create-table.
statement for the `event' table might look like this:

mysql> CREATE TABLE event (name VARCHAR(20), date DATE,
-> type VARCHAR(15), remark VARCHAR(255));

As with the `pet' table, it is easiest to load the initial records by
creating a tab-delimited text file containing the following information.

name date type remark
Fluffy 1995-05-15 litter 4 kittens, 3 female, 1
male
Buffy 1993-06-23 litter 5 puppies, 2 female, 3
male
Buffy 1994-06-19 litter 3 puppies, 3 female
Chirpy 1999-03-21 vet needed beak straightened
Slim 1997-08-03 vet broken rib
Bowser 1991-10-12 kennel
Fang 1991-10-12 kennel
Fang 1998-08-28 birthday Gave him a new chew toy
Claws 1998-03-17 birthday Gave him a new flea
collar
Whistler 1998-12-09 birthday First birthday

Load the records like this:

mysql> LOAD DATA LOCAL INFILE 'event.txt' INTO TABLE event;

Based on what you have learned from the queries that you have run on
the `pet' table, you should be able to perform retrievals on the
records in the `event' table; the principles are the same. But when is
the `event' table by itself insufficient to answer questions you might
ask?

Suppose that you want to find out the ages at which each pet had its
litters. We saw earlier how to calculate ages from two dates. The
litter date of the mother is in the `event' table, but to calculate her
age on that date you need her birth date, which is stored in the `pet'
table. This means the query requires both tables:

There are several things to note about this query:

* The `FROM' clause joins two tables because the query needs to pull
information from both of them.

* When combining (joining) information from multiple tables, you
need to specify how records in one table can be matched to records
in the other. This is easy because they both have a `name' column.
The query uses `ON' clause to match up records in the two tables
based on the `name' values.

The query uses an `INNER JOIN' to combine the tables. An `INNER
JOIN' permits rows from either table to appear in the result if
and only if both tables meet the conditions specified in the `ON'
clause. In this example, the `ON' clause specifies that the `name'
column in the `pet' table must match the `name' column in the
`event' table. If a name appears in one table but not the other,
the row will not appear in the result because the condition in the
`ON' clause fails.

* Because the `name' column occurs in both tables, you must be
specific about which table you mean when referring to the column.
This is done by prepending the table name to the column name.

You need not have two different tables to perform a join. Sometimes it
is useful to join a table to itself, if you want to compare records in
a table to other records in that same table. For example, to find
breeding pairs among your pets, you can join the `pet' table with
itself to produce candidate pairs of males and females of like species:

mysql> SELECT p1.name, p1.sex, p2.name, p2.sex, p1.species
-> FROM pet AS p1 INNER JOIN pet AS p2
-> ON p1.species = p2.species AND p1.sex = 'f' AND p2.sex = 'm';
+--------+------+--------+------+---------+
| name | sex | name | sex | species |
+--------+------+--------+------+---------+
| Fluffy | f | Claws | m | cat |
| Buffy | f | Fang | m | dog |
| Buffy | f | Bowser | m | dog |
+--------+------+--------+------+---------+

In this query, we specify aliases for the table name to refer to the
columns and keep straight which instance of the table each column
reference is associated with.

File: manual.info, Node: getting-information, Next: batch-mode, Prev: database-use, Up: tutorial

4.4 Getting Information About Databases and Tables
==================================================

What if you forget the name of a database or table, or what the
structure of a given table is (for example, what its columns are
called)? MySQL addresses this problem through several statements that
provide information about the databases and tables it supports.

You have previously seen *Note `SHOW DATABASES': show-databases, which
lists the databases managed by the server. To find out which database
is currently selected, use the `DATABASE()' function:

mysql> SELECT DATABASE();
+------------+
| DATABASE() |
+------------+
| menagerie |
+------------+

If you have not yet selected any database, the result is `NULL'.

To find out what tables the default database contains (for example,
when you are not sure about the name of a table), use this command:

mysql> SHOW TABLES;
+---------------------+
| Tables_in_menagerie |
+---------------------+
| event |
| pet |
+---------------------+

The name of the column in the output produced by this statement is
always `Tables_in_DB_NAME', where DB_NAME is the name of the database.
See *Note show-tables::, for more information.

If you want to find out about the structure of a table, the *Note
`DESCRIBE': describe. statement is useful; it displays information
about each of a table's columns:

`Field' indicates the column name, `Type' is the data type for the
column, `NULL' indicates whether the column can contain `NULL' values,
`Key' indicates whether the column is indexed, and `Default' specifies
the column's default value. `Extra' displays special information about
columns: If a column was created with the `AUTO_INCREMENT' option, the
value will be `auto_increment' rather than empty.

`DESC' is a short form of *Note `DESCRIBE': describe. See *Note
describe::, for more information.

You can obtain the *Note `CREATE TABLE': create-table. statement
necessary to create an existing table using the *Note `SHOW CREATE
TABLE': show-create-table. statement. See *Note show-create-table::.

If you have indexes on a table, `SHOW INDEX FROM TBL_NAME' produces
information about them. See *Note show-index::, for more about this
statement.

File: manual.info, Node: batch-mode, Next: examples, Prev: getting-information, Up: tutorial

4.5 Using `mysql' in Batch Mode
===============================

In the previous sections, you used *Note `mysql': mysql. interactively
to enter queries and view the results. You can also run *Note `mysql':
mysql. in batch mode. To do this, put the commands you want to run in a
file, then tell *Note `mysql': mysql. to read its input from the file:

shell> mysql < BATCH-FILE

If you are running *Note `mysql': mysql. under Windows and have some
special characters in the file that cause problems, you can do this:

C:\> mysql -e "source BATCH-FILE"

If you need to specify connection parameters on the command line, the
command might look like this:

shell> mysql -h HOST -u USER -p < BATCH-FILE
Enter password: ********

When you use *Note `mysql': mysql. this way, you are creating a script
file, then executing the script.

If you want the script to continue even if some of the statements in it
produce errors, you should use the `--force' command-line option.

Why use a script? Here are a few reasons:

* If you run a query repeatedly (say, every day or every week),
making it a script enables you to avoid retyping it each time you
execute it.

* You can generate new queries from existing ones that are similar
by copying and editing script files.

* Batch mode can also be useful while you're developing a query,
particularly for multiple-line commands or multiple-statement
sequences of commands. If you make a mistake, you don't have to
retype everything. Just edit your script to correct the error,
then tell *Note `mysql': mysql. to execute it again.

* If you have a query that produces a lot of output, you can run the
output through a pager rather than watching it scroll off the top
of your screen:

shell> mysql < BATCH-FILE | more

* You can catch the output in a file for further processing:

shell> mysql < BATCH-FILE > mysql.out

* You can distribute your script to other people so that they can
also run the commands.

* Some situations do not allow for interactive use, for example,
when you run a query from a `cron' job. In this case, you must use
batch mode.

The default output format is different (more concise) when you run
*Note `mysql': mysql. in batch mode than when you use it interactively.
For example, the output of `SELECT DISTINCT species FROM pet' looks
like this when *Note `mysql': mysql. is run interactively:

+---------+
| species |
+---------+
| bird |
| cat |
| dog |
| hamster |
| snake |
+---------+

In batch mode, the output looks like this instead:

species
bird
cat
dog
hamster
snake

If you want to get the interactive output format in batch mode, use
`mysql -t'. To echo to the output the commands that are executed, use
`mysql -vvv'.

You can also use scripts from the *Note `mysql': mysql. prompt by using
the `source' command or `\.' command:

mysql> source FILENAME;
mysql> \. FILENAME

See *Note batch-commands::, for more information.

File: manual.info, Node: examples, Next: apache, Prev: batch-mode, Up: tutorial

4.6 Examples of Common Queries
==============================

* Menu:

* example-maximum-column:: The Maximum Value for a Column
* example-maximum-row:: The Row Holding the Maximum of a Certain Column
* example-maximum-column-group:: Maximum of Column per Group
* example-maximum-column-group-row:: The Rows Holding the Group-wise Maximum of a Certain Column
* example-user-variables:: Using User-Defined Variables
* example-foreign-keys:: Using Foreign Keys
* searching-on-two-keys:: Searching on Two Keys
* calculating-days:: Calculating Visits Per Day
* example-auto-increment:: Using `AUTO_INCREMENT'

Here are examples of how to solve some common problems with MySQL.

Some of the examples use the table `shop' to hold the price of each
article (item number) for certain traders (dealers). Supposing that
each trader has a single fixed price per article, then (`article',
`dealer') is a primary key for the records.

Start the command-line tool *Note `mysql': mysql. and select a database:

shell> mysql YOUR-DATABASE-NAME

(In most MySQL installations, you can use the database named `test').

You can create and populate the example table with these statements:

CREATE TABLE shop (
article INT(4) UNSIGNED ZEROFILL DEFAULT '0000' NOT NULL,
dealer CHAR(20) DEFAULT '' NOT NULL,
price DOUBLE(16,2) DEFAULT '0.00' NOT NULL,
PRIMARY KEY(article, dealer));
INSERT INTO shop VALUES
(1,'A',3.45),(1,'B',3.99),(2,'A',10.99),(3,'B',1.45),
(3,'C',1.69),(3,'D',1.25),(4,'D',19.95);

After issuing the statements, the table should have the following
contents:

SELECT * FROM shop;

+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0001 | A | 3.45 |
| 0001 | B | 3.99 |
| 0002 | A | 10.99 |
| 0003 | B | 1.45 |
| 0003 | C | 1.69 |
| 0003 | D | 1.25 |
| 0004 | D | 19.95 |
+---------+--------+-------+

File: manual.info, Node: example-maximum-column, Next: example-maximum-row, Prev: examples, Up: examples

4.6.1 The Maximum Value for a Column
------------------------------------

`What is the highest item number?'

SELECT MAX(article) AS article FROM shop;

+---------+
| article |
+---------+
| 4 |
+---------+

File: manual.info, Node: example-maximum-row, Next: example-maximum-column-group, Prev: example-maximum-column, Up: examples

4.6.2 The Row Holding the Maximum of a Certain Column
-----------------------------------------------------

_Task: Find the number, dealer, and price of the most expensive
article._

This is easily done with a subquery:

SELECT article, dealer, price
FROM shop
WHERE price=(SELECT MAX(price) FROM shop);

+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0004 | D | 19.95 |
+---------+--------+-------+

Other solutions are to use a `LEFT JOIN' or to sort all rows descending
by price and get only the first row using the MySQL-specific `LIMIT'
clause:

SELECT s1.article, s1.dealer, s1.price
FROM shop s1
LEFT JOIN shop s2 ON s1.price < s2.price
WHERE s2.article IS NULL;

SELECT article, dealer, price
FROM shop
ORDER BY price DESC
LIMIT 1;

*Note*:

If there were several most expensive articles, each with a price of
19.95, the `LIMIT' solution would show only one of them.

File: manual.info, Node: example-maximum-column-group, Next: example-maximum-column-group-row, Prev: example-maximum-row, Up: examples

4.6.3 Maximum of Column per Group
---------------------------------

_Task: Find the highest price per article._

SELECT article, MAX(price) AS price
FROM shop
GROUP BY article;

+---------+-------+
| article | price |
+---------+-------+
| 0001 | 3.99 |
| 0002 | 10.99 |
| 0003 | 1.69 |
| 0004 | 19.95 |
+---------+-------+

File: manual.info, Node: example-maximum-column-group-row, Next: example-user-variables, Prev: example-maximum-column-group, Up: examples

4.6.4 The Rows Holding the Group-wise Maximum of a Certain Column
-----------------------------------------------------------------

_Task: For each article, find the dealer or dealers with the most
expensive price._

This problem can be solved with a subquery like this one:

SELECT article, dealer, price
FROM shop s1
WHERE price=(SELECT MAX(s2.price)
FROM shop s2
WHERE s1.article = s2.article);

+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0001 | B | 3.99 |
| 0002 | A | 10.99 |
| 0003 | C | 1.69 |
| 0004 | D | 19.95 |
+---------+--------+-------+

The preceding example uses a correlated subquery, which can be
inefficient (see *Note correlated-subqueries::). Other possibilities
for solving the problem are to use an uncorrelated subquery in the
`FROM' clause or a `LEFT JOIN':

SELECT s1.article, dealer, s1.price
FROM shop s1
JOIN (
SELECT article, MAX(price) AS price
FROM shop
GROUP BY article) AS s2
ON s1.article = s2.article AND s1.price = s2.price;

SELECT s1.article, s1.dealer, s1.price
FROM shop s1
LEFT JOIN shop s2 ON s1.article = s2.article AND s1.price < s2.price
WHERE s2.article IS NULL;

The `LEFT JOIN' works on the basis that when `s1.price' is at its
maximum value, there is no `s2.price' with a greater value and the `s2'
rows values will be `NULL'. See *Note join::.

File: manual.info, Node: example-user-variables, Next: example-foreign-keys, Prev: example-maximum-column-group-row, Up: examples

4.6.5 Using User-Defined Variables
----------------------------------

You can employ MySQL user variables to remember results without having
to store them in temporary variables in the client. (See *Note
user-variables::.)

For example, to find the articles with the highest and lowest price you
can do this:

mysql> SELECT @min_price:=MIN(price),@max_price:=MAX(price) FROM shop;
mysql> SELECT * FROM shop WHERE price=@min_price OR price=@max_price;
+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0003 | D | 1.25 |
| 0004 | D | 19.95 |
+---------+--------+-------+

*Note*:

It is also possible to store the name of a database object such as a
table or a column in a user variable and then to use this variable in
an SQL statement; however, this requires the use of a prepared
statement. See *Note sql-syntax-prepared-statements::, for more
information.

File: manual.info, Node: example-foreign-keys, Next: searching-on-two-keys, Prev: example-user-variables, Up: examples

4.6.6 Using Foreign Keys
------------------------

In MySQL, `InnoDB' tables support checking of foreign key constraints.
See *Note innodb-storage-engine::, and *Note ansi-diff-foreign-keys::.

A foreign key constraint is not required merely to join two tables. For
storage engines other than `InnoDB', it is possible when defining a
column to use a `REFERENCES TBL_NAME(COL_NAME)' clause, which has no
actual effect, and _serves only as a memo or comment to you that the
column which you are currently defining is intended to refer to a
column in another table_. It is extremely important to realize when
using this syntax that:

* MySQL does not perform any sort of `CHECK' to make sure that
COL_NAME actually exists in TBL_NAME (or even that TBL_NAME itself
exists).

* MySQL does not perform any sort of action on TBL_NAME such as
deleting rows in response to actions taken on rows in the table
which you are defining; in other words, this syntax induces no `ON
DELETE' or `ON UPDATE' behavior whatsoever. (Although you can
write an `ON DELETE' or `ON UPDATE' clause as part of the
`REFERENCES' clause, it is also ignored.)

* This syntax creates a _column_; it does *not* create any sort of
index or key.

You can use a column so created as a join column, as shown here:

CREATE TABLE person (
id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT,
name CHAR(60) NOT NULL,
PRIMARY KEY (id)
);

CREATE TABLE shirt (
id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT,
style ENUM('t-shirt', 'polo', 'dress') NOT NULL,
color ENUM('red', 'blue', 'orange', 'white', 'black') NOT NULL,
owner SMALLINT UNSIGNED NOT NULL REFERENCES person(id),
PRIMARY KEY (id)
);

INSERT INTO person VALUES (NULL, 'Antonio Paz');

SELECT @last := LAST_INSERT_ID();

INSERT INTO shirt VALUES
(NULL, 'polo', 'blue', @last),
(NULL, 'dress', 'white', @last),
(NULL, 't-shirt', 'blue', @last);

INSERT INTO person VALUES (NULL, 'Lilliana Angelovska');

SELECT @last := LAST_INSERT_ID();

INSERT INTO shirt VALUES
(NULL, 'dress', 'orange', @last),
(NULL, 'polo', 'red', @last),
(NULL, 'dress', 'blue', @last),
(NULL, 't-shirt', 'white', @last);

SELECT * FROM person;
+----+---------------------+
| id | name |
+----+---------------------+
| 1 | Antonio Paz |
| 2 | Lilliana Angelovska |
+----+---------------------+

SELECT * FROM shirt;
+----+---------+--------+-------+
| id | style | color | owner |
+----+---------+--------+-------+
| 1 | polo | blue | 1 |
| 2 | dress | white | 1 |
| 3 | t-shirt | blue | 1 |
| 4 | dress | orange | 2 |
| 5 | polo | red | 2 |
| 6 | dress | blue | 2 |
| 7 | t-shirt | white | 2 |
+----+---------+--------+-------+

SELECT s.* FROM person p INNER JOIN shirt s
ON s.owner = p.id
WHERE p.name LIKE 'Lilliana%'
AND s.color <> 'white';

+----+-------+--------+-------+
| id | style | color | owner |
+----+-------+--------+-------+
| 4 | dress | orange | 2 |
| 5 | polo | red | 2 |
| 6 | dress | blue | 2 |
+----+-------+--------+-------+

When used in this fashion, the `REFERENCES' clause is not displayed in
the output of *Note `SHOW CREATE TABLE': show-create-table. or *Note
`DESCRIBE': describe.:

SHOW CREATE TABLE shirt\G
*************************** 1. row ***************************
Table: shirt
Create Table: CREATE TABLE `shirt` (
`id` smallint(5) unsigned NOT NULL auto_increment,
`style` enum('t-shirt','polo','dress') NOT NULL,
`color` enum('red','blue','orange','white','black') NOT NULL,
`owner` smallint(5) unsigned NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1

The use of `REFERENCES' in this way as a comment or `reminder' in a
column definition works with both `MyISAM' and `BerkeleyDB' tables.

File: manual.info, Node: searching-on-two-keys, Next: calculating-days, Prev: example-foreign-keys, Up: examples

4.6.7 Searching on Two Keys
---------------------------

An `OR' using a single key is well optimized, as is the handling of
`AND'.

The one tricky case is that of searching on two different keys combined
with `OR':

SELECT field1_index, field2_index FROM test_table
WHERE field1_index = '1' OR field2_index = '1'

This case is optimized from MySQL 5.0.0. See *Note
index-merge-optimization::.

You can also solve the problem efficiently by using a *Note `UNION':
union. that combines the output of two separate *Note `SELECT': select.
statements. See *Note union::.

Each *Note `SELECT': select. searches only one key and can be optimized:

SELECT field1_index, field2_index
FROM test_table WHERE field1_index = '1'
UNION
SELECT field1_index, field2_index
FROM test_table WHERE field2_index = '1';

File: manual.info, Node: calculating-days, Next: example-auto-increment, Prev: searching-on-two-keys, Up: examples

4.6.8 Calculating Visits Per Day
--------------------------------

The following example shows how you can use the bit group functions to
calculate the number of days per month a user has visited a Web page.

CREATE TABLE t1 (year YEAR(4), month INT(2) UNSIGNED ZEROFILL,
day INT(2) UNSIGNED ZEROFILL);
INSERT INTO t1 VALUES(2000,1,1),(2000,1,20),(2000,1,30),(2000,2,2),
(2000,2,23),(2000,2,23);

The example table contains year-month-day values representing visits by
users to the page. To determine how many different days in each month
these visits occur, use this query:

SELECT year,month,BIT_COUNT(BIT_OR(1<<day)) AS days FROM t1
GROUP BY year,month;

Which returns:

+------+-------+------+
| year | month | days |
+------+-------+------+
| 2000 | 01 | 3 |
| 2000 | 02 | 2 |
+------+-------+------+

The query calculates how many different days appear in the table for
each year/month combination, with automatic removal of duplicate
entries.

File: manual.info, Node: example-auto-increment, Prev: calculating-days, Up: examples

4.6.9 Using `AUTO_INCREMENT'
----------------------------

The `AUTO_INCREMENT' attribute can be used to generate a unique
identity for new rows:

CREATE TABLE animals (
id MEDIUMINT NOT NULL AUTO_INCREMENT,
name CHAR(30) NOT NULL,
PRIMARY KEY (id)
) ENGINE=MyISAM;

INSERT INTO animals (name) VALUES
('dog'),('cat'),('penguin'),
('lax'),('whale'),('ostrich');

SELECT * FROM animals;

Which returns:

+----+---------+
| id | name |
+----+---------+
| 1 | dog |
| 2 | cat |
| 3 | penguin |
| 4 | lax |
| 5 | whale |
| 6 | ostrich |
+----+---------+

No value was specified for the `AUTO_INCREMENT' column, so MySQL
assigned sequence numbers automatically. You can also explicitly assign
`NULL' or 0 to the column to generate sequence numbers.

You can retrieve the most recent `AUTO_INCREMENT' value with the
`LAST_INSERT_ID()' SQL function or the *Note `mysql_insert_id()':
mysql-insert-id. C API function. These functions are
connection-specific, so their return values are not affected by another
connection which is also performing inserts.

Use a large enough integer data type for the `AUTO_INCREMENT' column to
hold the maximum sequence value you will need. When the column reaches
the upper limit of the data type, the next attempt to generate a
sequence number fails. For example, if you use *Note `TINYINT':
numeric-types, the maximum permissible sequence number is 127. For
*Note `TINYINT UNSIGNED': numeric-types, the maximum is 255.

*Note*:

For a multiple-row insert, `LAST_INSERT_ID()' and *Note
`mysql_insert_id()': mysql-insert-id. actually return the
`AUTO_INCREMENT' key from the _first_ of the inserted rows. This enables
multiple-row inserts to be reproduced correctly on other servers in a
replication setup.

For `MyISAM' and `BDB' tables you can specify `AUTO_INCREMENT' on a
secondary column in a multiple-column index. In this case, the generated
value for the `AUTO_INCREMENT' column is calculated as
`MAX(AUTO_INCREMENT_COLUMN) + 1 WHERE prefix=GIVEN-PREFIX'. This is
useful when you want to put data into ordered groups.

CREATE TABLE animals (
grp ENUM('fish','mammal','bird') NOT NULL,
id MEDIUMINT NOT NULL AUTO_INCREMENT,
name CHAR(30) NOT NULL,
PRIMARY KEY (grp,id)
) ENGINE=MyISAM;

INSERT INTO animals (grp,name) VALUES
('mammal','dog'),('mammal','cat'),
('bird','penguin'),('fish','lax'),('mammal','whale'),
('bird','ostrich');

SELECT * FROM animals ORDER BY grp,id;

Which returns:

+--------+----+---------+
| grp | id | name |
+--------+----+---------+
| fish | 1 | lax |
| mammal | 1 | dog |
| mammal | 2 | cat |
| mammal | 3 | whale |
| bird | 1 | penguin |
| bird | 2 | ostrich |
+--------+----+---------+

In this case (when the `AUTO_INCREMENT' column is part of a
multiple-column index), `AUTO_INCREMENT' values are reused if you
delete the row with the biggest `AUTO_INCREMENT' value in any group.
This happens even for `MyISAM' tables, for which `AUTO_INCREMENT'
values normally are not reused.

If the `AUTO_INCREMENT' column is part of multiple indexes, MySQL will
generate sequence values using the index that begins with the
`AUTO_INCREMENT' column, if there is one. For example, if the `animals'
table contained indexes `PRIMARY KEY (grp, id)' and `INDEX (id)', MySQL
would ignore the `PRIMARY KEY' for generating sequence values. As a
result, the table would contain a single sequence, not a sequence per
`grp' value.

To start with an `AUTO_INCREMENT' value other than 1, you can set that
value with *Note `CREATE TABLE': create-table. or *Note `ALTER TABLE':
alter-table, like this:

mysql> ALTER TABLE tbl AUTO_INCREMENT = 100;

More information about `AUTO_INCREMENT' is available here:

* How to assign the `AUTO_INCREMENT' attribute to a column: *Note
create-table::, and *Note alter-table::.

* How `AUTO_INCREMENT' behaves depending on the
`NO_AUTO_VALUE_ON_ZERO' SQL mode: *Note server-sql-mode::.

* How to use the `LAST_INSERT_ID()' function to find the row that
contains the most recent `AUTO_INCREMENT' value: *Note
information-functions::.

* Setting the `AUTO_INCREMENT' value to be used: *Note
server-system-variables::.

* `AUTO_INCREMENT' and replication: *Note
replication-features-auto-increment::.

* Server-system variables related to `AUTO_INCREMENT'
(`auto_increment_increment' and `auto_increment_offset') that can
be used for replication: *Note server-system-variables::.

File: manual.info, Node: apache, Prev: examples, Up: tutorial

4.7 Using MySQL with Apache
===========================

There are programs that let you authenticate your users from a MySQL
database and also let you write your log files into a MySQL table.

You can change the Apache logging format to be easily readable by MySQL
by putting the following into the Apache configuration file:

LogFormat \
"\"%h\",%{%Y%m%d%H%M%S}t,%>s,\"%b\",\"%{Content-Type}o\", \
\"%U\",\"%{Referer}i\",\"%{User-Agent}i\""

To load a log file in that format into MySQL, you can use a statement
something like this:

LOAD DATA INFILE '/LOCAL/ACCESS_LOG' INTO TABLE TBL_NAME
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' ESCAPED BY '\\'

The named table should be created to have columns that correspond to
those that the `LogFormat' line writes to the log file.

File: manual.info, Node: programs, Next: server-administration, Prev: tutorial, Up: Top

5 MySQL Programs
****************

* Menu:

* programs-overview:: Overview of MySQL Programs
* programs-using:: Using MySQL Programs
* programs-server:: MySQL Server and Server-Startup Programs
* programs-installation:: MySQL Installation-Related Programs
* programs-client:: MySQL Client Programs
* programs-admin-utils:: MySQL Administrative and Utility Programs
* programs-development:: MySQL Program Development Utilities
* programs-miscellaneous:: Miscellaneous Programs

This chapter provides a brief overview of the MySQL command-line
programs provided by Oracle Corporation. It also discusses the general
syntax for specifying options when you run these programs. Most
programs have options that are specific to their own operation, but the
option syntax is similar for all of them. Finally, the chapter provides
more detailed descriptions of individual programs, including which
options they recognize.

File: manual.info, Node: programs-overview, Next: programs-using, Prev: programs, Up: programs

5.1 Overview of MySQL Programs
==============================

There are many different programs in a MySQL installation. This section
provides a brief overview of them. Later sections provide a more
detailed description of each one, with the exception of MySQL Cluster
programs. Each program's description indicates its invocation syntax
and the options that it supports. *Note mysql-cluster::, describes
programs specific to MySQL Cluster.

Most MySQL distributions include all of these programs, except for
those programs that are platform-specific. (For example, the server
startup scripts are not used on Windows.) The exception is that RPM
distributions are more specialized. There is one RPM for the server,
another for client programs, and so forth. If you appear to be missing
one or more programs, see *Note installing::, for information on types
of distributions and what they contain. It may be that you have a
distribution that does not include all programs and you need to install
an additional package.

Each MySQL program takes many different options. Most programs provide
a `--help' option that you can use to get a description of the
program's different options. For example, try *Note `mysql --help':
mysql.

You can override default option values for MySQL programs by specifying
options on the command line or in an option file. See *Note
programs-using::, for general information on invoking programs and
specifying program options.

The MySQL server, *Note `mysqld': mysqld, is the main program that does
most of the work in a MySQL installation. The server is accompanied by
several related scripts that assist you in starting and stopping the
server:

* *Note `mysqld': mysqld.

The SQL daemon (that is, the MySQL server). To use client
programs, *Note `mysqld': mysqld. must be running, because clients
gain access to databases by connecting to the server. See *Note
mysqld::.

* *Note `mysqld_safe': mysqld-safe.

A server startup script. *Note `mysqld_safe': mysqld-safe.
attempts to start *Note `mysqld': mysqld. See *Note mysqld-safe::.

* *Note `mysql.server': mysql-server.

A server startup script. This script is used on systems that use
System V-style run directories containing scripts that start
system services for particular run levels. It invokes *Note
`mysqld_safe': mysqld-safe. to start the MySQL server. See *Note
mysql-server::.

* *Note `mysqld_multi': mysqld-multi.

A server startup script that can start or stop multiple servers
installed on the system. See *Note mysqld-multi::. As of MySQL
5.0.3 (Unix-like systems) or 5.0.13 (Windows), an alternative to
*Note `mysqld_multi': mysqld-multi. is `mysqlmanager', the MySQL
Instance Manager. See *Note instance-manager::.

There are several programs that perform setup operations during MySQL
installation or upgrading:

* *Note `comp_err': comp-err.

This program is used during the MySQL build/installation process.
It compiles error message files from the error source files. See
*Note comp-err::.

* `make_binary_distribution'

This program makes a binary release of a compiled MySQL. This
could be sent by FTP to `/pub/mysql/upload/' on `ftp.mysql.com'
for the convenience of other MySQL users.

* *Note `make_win_bin_dist': make-win-bin-dist.

This program is used on Windows. It packages a MySQL distribution
for installation after the source distribution has been built. See
*Note make-win-bin-dist::.

* *Note `mysql_fix_privilege_tables': mysql-fix-privilege-tables.

This program is used after a MySQL upgrade operation. It updates
the grant tables with any changes that have been made in newer
versions of MySQL. See *Note mysql-fix-privilege-tables::.

Note: As of MySQL 5.0.19, this program has been superseded by
*Note `mysql_upgrade': mysql-upgrade. and should no longer be used.

* *Note `mysql_install_db': mysql-install-db.

This script creates the MySQL database and initializes the grant
tables with default privileges. It is usually executed only once,
when first installing MySQL on a system. See *Note
mysql-install-db::, *Note unix-postinstallation::, and *Note
mysql-install-db::.

* *Note `mysql_secure_installation': mysql-secure-installation.

This program enables you to improve the security of your MySQL
installation. SQL. See *Note mysql-secure-installation::.

* *Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql.

This program loads the time zone tables in the `mysql' database
using the contents of the host system _zoneinfo_ database (the set
of files describing time zones). SQL. See *Note
mysql-tzinfo-to-sql::.

* *Note `mysql_upgrade': mysql-upgrade.

This program is used after a MySQL upgrade operation. It checks
tables for incompatibilities and repairs them if necessary, and
updates the grant tables with any changes that have been made in
newer versions of MySQL. See *Note mysql-upgrade::.

* *Note `make_win_src_distribution': make-win-src-distribution.

This program is used on Unix or Unix-like systems to create a
MySQL source distribution that can be compiled on Windows. See
*Note windows-sourcetree-build::, and *Note
make-win-src-distribution::.

MySQL client programs:

* *Note `mysql': mysql.

The command-line tool for interactively entering SQL statements or
executing them from a file in batch mode. See *Note mysql::.

* *Note `mysqladmin': mysqladmin.

A client that performs administrative operations, such as creating
or dropping databases, reloading the grant tables, flushing tables
to disk, and reopening log files. *Note `mysqladmin': mysqladmin.
can also be used to retrieve version, process, and status
information from the server. See *Note mysqladmin::.

* *Note `mysqlcheck': mysqlcheck.

A table-maintenance client that checks, repairs, analyzes, and
optimizes tables. See *Note mysqlcheck::.

* *Note `mysqldump': mysqldump.

A client that dumps a MySQL database into a file as SQL, text, or
XML. See *Note mysqldump::.

* *Note `mysqlimport': mysqlimport.

A client that imports text files into their respective tables
using *Note `LOAD DATA INFILE': load-data. See *Note mysqlimport::.

* *Note `mysqlshow': mysqlshow.

A client that displays information about databases, tables,
columns, and indexes. See *Note mysqlshow::.

MySQL administrative and utility programs:

* *Note `innochecksum': innochecksum.

An offline `InnoDB' offline file checksum utility. See *Note
innochecksum::.

* *Note `myisam_ftdump': myisam-ftdump.

A utility that displays information about full-text indexes in
`MyISAM' tables. See *Note myisam-ftdump::.

* *Note `myisamchk': myisamchk.

A utility to describe, check, optimize, and repair `MyISAM'
tables. See *Note myisamchk::.

* *Note `myisamlog': myisamlog, `isamlog'

A utility that processes the contents of a `MyISAM' log file. See
*Note myisamlog::.

* *Note `myisampack': myisampack.

A utility that compresses `MyISAM' tables to produce smaller
read-only tables. See *Note myisampack::.

* *Note `mysqlaccess': mysqlaccess.

A script that checks the access privileges for a host name, user
name, and database combination. See *Note mysqlaccess::.

* *Note `mysqlbinlog': mysqlbinlog.

A utility for reading statements from a binary log. The log of
executed statements contained in the binary log files can be used
to help recover from a crash. See *Note mysqlbinlog::.

* *Note `mysqldumpslow': mysqldumpslow.

A utility to read and summarize the contents of a slow query log.
See *Note mysqldumpslow::.

* *Note `mysqlhotcopy': mysqlhotcopy.

A utility that quickly makes backups of `MyISAM' tables while the
server is running. See *Note mysqlhotcopy::.

* `mysqlmanager'

The MySQL Instance Manager, a program for monitoring and managing
MySQL servers. See *Note instance-manager::.

*Important*:

MySQL Instance Manager has been deprecated and is removed in MySQL
5.4.

* *Note `mysql_convert_table_format': mysql-convert-table-format.

A utility that converts tables in a database to use a given
storage engine. See *Note mysql-convert-table-format::.

* *Note `mysql_explain_log': mysql-explain-log.

A utility that analyzes queries in the MySQL query log using *Note
`EXPLAIN': explain. See *Note mysql-explain-log::.

* *Note `mysql_find_rows': mysql-find-rows.

A utility that reads files containing SQL statements (such as
update logs) and extracts statements that match a given regular
expression. See *Note mysql-find-rows::.

* *Note `mysql_fix_extensions': mysql-fix-extensions.

A utility that converts the extensions for `MyISAM' table files to
lowercase. This can be useful after transferring the files from a
system with case-insensitive file names to a system with
case-sensitive file names. See *Note mysql-fix-extensions::.

* *Note `mysql_setpermission': mysql-setpermission.

A utility for interactively setting permissions in the MySQL grant
tables. See *Note mysql-setpermission::.

* *Note `mysql_tableinfo': mysql-tableinfo.

A utility that generates database metadata. *Note
mysql-tableinfo::.

* *Note `mysql_waitpid': mysql-waitpid.

A utility that kills the process with a given process ID. See
*Note mysql-waitpid::.

* *Note `mysql_zap': mysql-zap.

A utility that kills processes that match a pattern. See *Note
mysql-zap::.

MySQL program-development utilities:

* *Note `msql2mysql': msql2mysql.

A shell script that converts `mSQL' programs to MySQL. It doesn't
handle every case, but it gives a good start when converting. See
*Note msql2mysql::.

* *Note `mysql_config': mysql-config.

A shell script that produces the option values needed when
compiling MySQL programs. See *Note mysql-config::.

* *Note `my_print_defaults': my-print-defaults.

A utility that shows which options are present in option groups of
option files. See *Note my-print-defaults::.

* *Note `resolve_stack_dump': resolve-stack-dump.

A utility program that resolves a numeric stack trace dump to
symbols. See *Note resolve-stack-dump::.

Miscellaneous utilities:

* *Note `perror': perror.

A utility that displays the meaning of system or MySQL error
codes. See *Note perror::.

* *Note `replace': replace-utility.

A utility program that performs string replacement in the input
text. See *Note replace-utility::.

* *Note `resolveip': resolveip.

A utility program that resolves a host name to an IP address or
vice versa. See *Note resolveip::.

Oracle Corporation also provides several GUI tools for administering
and otherwise working with MySQL Server:

* MySQL Workbench: This is the latest graphical tool for working
with MySQL databases.

* MySQL Administrator: This tool is used for administering MySQL
servers, databases, tables, and user accounts.

* MySQL Query Browser: This graphical tool is used for creating,
executing, and optimizing queries on MySQL databases.

* MySQL Migration Toolkit: This tool helps you migrate schemas and
data from other relational database management systems for use
with MySQL.

These GUI programs are available at `http://dev.mysql.com/downloads/'.
Each has its own manual that you can access at
`http://dev.mysql.com/doc/'.

MySQL client programs that communicate with the server using the MySQL
client/server library use the following environment variables.

Environment Meaning
Variable
`MYSQL_UNIX_PORT' The default Unix socket file; used for connections to
`localhost'
`MYSQL_TCP_PORT' The default port number; used for TCP/IP connections
`MYSQL_PWD' The default password
`MYSQL_DEBUG' Debug trace options when debugging
`TMPDIR' The directory where temporary tables and files are
created

For a full list of environment variables used by MySQL programs, see
*Note environment-variables::.

Use of `MYSQL_PWD' is insecure. See *Note password-security-user::.

File: manual.info, Node: programs-using, Next: programs-server, Prev: programs-overview, Up: programs

5.2 Using MySQL Programs
========================

* Menu:

* invoking-programs:: Invoking MySQL Programs
* connecting:: Connecting to the MySQL Server
* program-options:: Specifying Program Options
* setting-environment-variables:: Setting Environment Variables

File: manual.info, Node: invoking-programs, Next: connecting, Prev: programs-using, Up: programs-using

5.2.1 Invoking MySQL Programs
-----------------------------

To invoke a MySQL program from the command line (that is, from your
shell or command prompt), enter the program name followed by any
options or other arguments needed to instruct the program what you want
it to do. The following commands show some sample program invocations.
``shell>'' represents the prompt for your command interpreter; it is
not part of what you type. The particular prompt you see depends on your
command interpreter. Typical prompts are `$' for `sh' or `bash', `%'
for `csh' or `tcsh', and `C:\>' for the Windows `command.com' or
`cmd.exe' command interpreters.

shell> mysql --user=root test
shell> mysqladmin extended-status variables
shell> mysqlshow --help
shell> mysqldump -u root personnel

Arguments that begin with a single or double dash (``-'', ``--'')
specify program options. Options typically indicate the type of
connection a program should make to the server or affect its
operational mode. Option syntax is described in *Note program-options::.

Nonoption arguments (arguments with no leading dash) provide additional
information to the program. For example, the *Note `mysql': mysql.
program interprets the first nonoption argument as a database name, so
the command `mysql --user=root test' indicates that you want to use the
`test' database.

Later sections that describe individual programs indicate which options
a program supports and describe the meaning of any additional nonoption
arguments.

Some options are common to a number of programs. The most frequently
used of these are the `--host' (or `-h'), `--user' (or `-u'), and
`--password' (or `-p') options that specify connection parameters.
They indicate the host where the MySQL server is running, and the user
name and password of your MySQL account. All MySQL client programs
understand these options; they enable you to specify which server to
connect to and the account to use on that server. Other connection
options are `--port' (or `-P') to specify a TCP/IP port number and
`--socket' (or `-S') to specify a Unix socket file on Unix (or named
pipe name on Windows). For more information on options that specify
connection options, see *Note connecting::.

You may find it necessary to invoke MySQL programs using the path name
to the `bin' directory in which they are installed. This is likely to
be the case if you get a `program not found' error whenever you attempt
to run a MySQL program from any directory other than the `bin'
directory. To make it more convenient to use MySQL, you can add the
path name of the `bin' directory to your `PATH' environment variable
setting. That enables you to run a program by typing only its name, not
its entire path name. For example, if *Note `mysql': mysql. is
installed in `/usr/local/mysql/bin', you can run the program by
invoking it as *Note `mysql': mysql, and it is not necessary to invoke
it as `/usr/local/mysql/bin/mysql'.

Consult the documentation for your command interpreter for instructions
on setting your `PATH' variable. The syntax for setting environment
variables is interpreter-specific. (Some information is given in *Note
setting-environment-variables::.) After modifying your `PATH' setting,
open a new console window on Windows or log in again on Unix so that
the setting goes into effect.

File: manual.info, Node: connecting, Next: program-options, Prev: invoking-programs, Up: programs-using

5.2.2 Connecting to the MySQL Server
------------------------------------

For a client program to be able to connect to the MySQL server, it must
use the proper connection parameters, such as the name of the host
where the server is running and the user name and password of your
MySQL account. Each connection parameter has a default value, but you
can override them as necessary using program options specified either
on the command line or in an option file.

The examples here use the *Note `mysql': mysql. client program, but the
principles apply to other clients such as *Note `mysqldump': mysqldump,
*Note `mysqladmin': mysqladmin, or *Note `mysqlshow': mysqlshow.

This command invokes *Note `mysql': mysql. without specifying any
connection parameters explicitly:

shell> mysql

Because there are no parameter options, the default values apply:

* The default host name is `localhost'. On Unix, this has a special
meaning, as described later.

* The default user name is `ODBC' on Windows or your Unix login name
on Unix.

* No password is sent if neither `-p' nor `--password' is given.

* For *Note `mysql': mysql, the first nonoption argument is taken as
the name of the default database. If there is no such option,
*Note `mysql': mysql. does not select a default database.

To specify the host name and user name explicitly, as well as a
password, supply appropriate options on the command line:

shell> mysql --host=localhost --user=myname --password=mypass mydb
shell> mysql -h localhost -u myname -pmypass mydb

For password options, the password value is optional:

* If you use a `-p' or `--password' option and specify the password
value, there must be _no space_ between `-p' or `--password=' and
the password following it.

* If you use a `-p' or `--password' option but do not specify the
password value, the client program prompts you to enter the
password. The password is not displayed as you enter it. This is
more secure than giving the password on the command line. Other
users on your system may be able to see a password specified on
the command line by executing a command such as `ps auxw'. See
*Note password-security-user::.

As just mentioned, including the password value on the command line can
be a security risk. To avoid this problem, specify the `--password' or
`-p' option without any following password value:

shell> mysql --host=localhost --user=myname --password mydb
shell> mysql -h localhost -u myname -p mydb

When the password option has no password value, the client program
prints a prompt and waits for you to enter the password. (In these
examples, `mydb' is _not_ interpreted as a password because it is
separated from the preceding password option by a space.)

On some systems, the library routine that MySQL uses to prompt for a
password automatically limits the password to eight characters. That
is a problem with the system library, not with MySQL. Internally,
MySQL does not have any limit for the length of the password. To work
around the problem, change your MySQL password to a value that is eight
or fewer characters long, or put your password in an option file.

On Unix, MySQL programs treat the host name `localhost' specially, in a
way that is likely different from what you expect compared to other
network-based programs. For connections to `localhost', MySQL programs
attempt to connect to the local server by using a Unix socket file.
This occurs even if a `--port' or `-P' option is given to specify a
port number. To ensure that the client makes a TCP/IP connection to the
local server, use `--host' or `-h' to specify a host name value of
`127.0.0.1', or the IP address or name of the local server. You can
also specify the connection protocol explicitly, even for `localhost',
by using the `--protocol=TCP' option. For example:

shell> mysql --host=127.0.0.1
shell> mysql --protocol=TCP

The `--protocol' option enables you to establish a particular type of
connection even when the other options would normally default to some
other protocol.

On Windows, you can force a MySQL client to use a named-pipe connection
by specifying the `--pipe' or `--protocol=PIPE' option, or by
specifying `.' (period) as the host name. If named-pipe connections are
not enabled, an error occurs. Use the `--socket' option to specify the
name of the pipe if you do not want to use the default pipe name.

Connections to remote servers always use TCP/IP. This command connects
to the server running on `remote.example.com' using the default port
number (3306):

shell> mysql --host=remote.example.com

To specify a port number explicitly, use the `--port' or `-P' option:

shell> mysql --host=remote.example.com --port=13306

You can specify a port number for connections to a local server, too.
However, as indicated previously, connections to `localhost' on Unix
will use a socket file by default. You will need to force a TCP/IP
connection as already described or any option that specifies a port
number will be ignored.

For this command, the program uses a socket file on Unix and the
`--port' option is ignored:

shell> mysql --port=13306 --host=localhost

To cause the port number to be used, invoke the program in either of
these ways:

shell> mysql --port=13306 --host=127.0.0.1
shell> mysql --port=13306 --protocol=TCP

The following list summarizes the options that can be used to control
how client programs connect to the server:

* `--host=HOST_NAME', `-h HOST_NAME'

The host where the server is running. The default value is
`localhost'.

* `--password[=PASS_VAL]', `-p[PASS_VAL]'

The password of the MySQL account. As described earlier, the
password value is optional, but if given, there must be _no space_
between `-p' or `--password=' and the password following it. The
default is to send no password.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. The server
must be started with the `--enable-named-pipe' option to enable
named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The port number to use for the connection, for connections made
using TCP/IP. The default port number is 3306.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

This option explicitly specifies a protocol to use for connecting
to the server. It is useful when the other connection parameters
normally would cause a protocol to be used other than the one you
want. For example, connections on Unix to `localhost' are made
using a Unix socket file by default:

shell> mysql --host=localhost

To force a TCP/IP connection to be used instead, specify a
`--protocol' option:

shell> mysql --host=localhost --protocol=TCP

The following table shows the permissible `--protocol' option
values and indicates the platforms on which each value may be
used. The values are not case sensitive.

`--protocol' Connection Protocol Permissible
Value Operating Systems
`TCP' TCP/IP connection to local or All
remote server
`SOCKET' Unix socket file connection to Unix only
local server
`PIPE' Named-pipe connection to local or Windows only
remote server
`MEMORY' Shared-memory connection to local Windows only
server

* `--shared-memory-base-name=NAME'

On Windows, the shared-memory name to use, for connections made
using shared memory to a local server. The default value is
`MYSQL'. The shared-memory name is case sensitive.

The server must be started with the `--shared-memory' option to
enable shared-memory connections.

* `--socket=FILE_NAME', `-S FILE_NAME'

On Unix, the name of the Unix socket file to use, for connections
made using a named pipe to a local server. The default Unix socket
file name is `/tmp/mysql.sock'.

On Windows, the name of the named pipe to use, for connections to
a local server. The default Windows pipe name is `MySQL'. The pipe
name is not case sensitive.

The server must be started with the `--enable-named-pipe' option to
enable named-pipe connections.

* `--ssl*'

Options that begin with `--ssl' are used for establishing a secure
connection to the server using SSL, if the server is configured
with SSL support. For details, see *Note ssl-options::.

* `--user=USER_NAME', `-u USER_NAME'

The user name of the MySQL account you want to use. The default
user name is `ODBC' on Windows or your Unix login name on Unix.

It is possible to specify different default values to be used when you
make a connection so that you need not enter them on the command line
each time you invoke a client program. This can be done in a couple of
ways:

* You can specify connection parameters in the `[client]' section of
an option file. The relevant section of the file might look like
this:

[client]
host=HOST_NAME
user=USER_NAME
password=YOUR_PASS

*Note option-files::, discusses option files further.

* You can specify some connection parameters using environment
variables. The host can be specified for *Note `mysql': mysql.
using `MYSQL_HOST'. The MySQL user name can be specified using
`USER' (this is for Windows and NetWare only). The password can be
specified using `MYSQL_PWD', although this is insecure; see *Note
password-security-user::. For a list of variables, see *Note
environment-variables::.

File: manual.info, Node: program-options, Next: setting-environment-variables, Prev: connecting, Up: programs-using

5.2.3 Specifying Program Options
--------------------------------

* Menu:

* command-line-options:: Using Options on the Command Line
* option-modifiers:: Program Option Modifiers
* option-files:: Using Option Files
* program-variables:: Using Options to Set Program Variables
* option-defaults-equals:: Option Defaults, Options Expecting Values, and the `=' Sign

There are several ways to specify options for MySQL programs:

* List the options on the command line following the program name.
This is common for options that apply to a specific invocation of
the program.

* List the options in an option file that the program reads when it
starts. This is common for options that you want the program to
use each time it runs.

* List the options in environment variables (see *Note
setting-environment-variables::). This method is useful for
options that you want to apply each time the program runs. In
practice, option files are used more commonly for this purpose,
but *Note multiple-unix-servers::, discusses one situation in
which environment variables can be very helpful. It describes a
handy technique that uses such variables to specify the TCP/IP
port number and Unix socket file for the server and for client
programs.

Options are processed in order, so if an option is specified multiple
times, the last occurrence takes precedence. The following command
causes *Note `mysql': mysql. to connect to the server running on
`localhost':

shell> mysql -h example.com -h localhost

If conflicting or related options are given, later options take
precedence over earlier options. The following command runs *Note
`mysql': mysql. in `no column names' mode:

shell> mysql --column-names --skip-column-names

MySQL programs determine which options are given first by examining
environment variables, then by reading option files, and then by
checking the command line. This means that environment variables have
the lowest precedence and command-line options the highest.

You can take advantage of the way that MySQL programs process options
by specifying default option values for a program in an option file.
That enables you to avoid typing them each time you run the program
while enabling you to override the defaults if necessary by using
command-line options.

An option can be specified by writing it in full or as any unambiguous
prefix. For example, the `--compress' option can be given to *Note
`mysqldump': mysqldump. as `--compr', but not as `--comp' because the
latter is ambiguous:

shell> mysqldump --comp
mysqldump: ambiguous option '--comp' (compatible, compress)

Be aware that the use of option prefixes can cause problems in the
event that new options are implemented for a program. A prefix that is
unambiguous now might become ambiguous in the future.

File: manual.info, Node: command-line-options, Next: option-modifiers, Prev: program-options, Up: program-options

5.2.3.1 Using Options on the Command Line
.........................................

Program options specified on the command line follow these rules:

* Options are given after the command name.

* An option argument begins with one dash or two dashes, depending
on whether it is a short form or long form of the option name.
Many options have both short and long forms. For example, `-?'
and `--help' are the short and long forms of the option that
instructs a MySQL program to display its help message.

* Option names are case sensitive. `-v' and `-V' are both legal and
have different meanings. (They are the corresponding short forms
of the `--verbose' and `--version' options.)

* Some options take a value following the option name. For example,
`-h localhost' or `--host=localhost' indicate the MySQL server
host to a client program. The option value tells the program the
name of the host where the MySQL server is running.

* For a long option that takes a value, separate the option name and
the value by an ``='' sign. For a short option that takes a value,
the option value can immediately follow the option letter, or
there can be a space between: `-hlocalhost' and `-h localhost' are
equivalent. An exception to this rule is the option for specifying
your MySQL password. This option can be given in long form as
`--password=PASS_VAL' or as `--password'. In the latter case (with
no password value given), the program prompts you for the
password. The password option also may be given in short form as
`-pPASS_VAL' or as `-p'. However, for the short form, if the
password value is given, it must follow the option letter with _no
intervening space_. The reason for this is that if a space follows
the option letter, the program has no way to tell whether a
following argument is supposed to be the password value or some
other kind of argument. Consequently, the following two commands
have two completely different meanings:

shell> mysql -ptest
shell> mysql -p test

The first command instructs *Note `mysql': mysql. to use a
password value of `test', but specifies no default database. The
second instructs *Note `mysql': mysql. to prompt for the password
value and to use `test' as the default database.

* Within option names, dash (``-'') and underscore (``_'') may be
used interchangeably. For example, `--skip-grant-tables' and
`--skip_grant_tables' are equivalent. (However, the leading dashes
cannot be given as underscores.)

* For options that take a numeric value, the value can be given with
a suffix of `K', `M', or `G' (either uppercase or lowercase) to
indicate a multiplier of 1024, 1024^2 or 1024^3. For example, the
following command tells *Note `mysqladmin': mysqladmin. to ping the
server 1024 times, sleeping 10 seconds between each ping:

mysql> mysqladmin --count=1K --sleep=10 ping

Option values that contain spaces must be quoted when given on the
command line. For example, the `--execute' (or `-e') option can be used
with *Note `mysql': mysql. to pass SQL statements to the server. When
this option is used, *Note `mysql': mysql. executes the statements in
the option value and exits. The statements must be enclosed by quotation
marks. For example, you can use the following command to obtain a list
of user accounts:

Note that the long form (`--execute') is followed by an equal sign
(`=').

If you wish to use quoted values within a statement, you will either
need to escape the inner quotation marks, or use a different type of
quotation marks within the statement from those used to quote the
statement itself. The capabilities of your command processor dictate
your choices for whether you can use single or double quotation marks
and the syntax for escaping quote characters. For example, if your
command processor supports quoting with single or double quotation
marks, you can use double quotation marks around the statement, and
single quotation marks for any quoted values within the statement.

Multiple SQL statements may be passed in the option value on the
command line, separated by semicolons:

shell> mysql -u root -p -e "SELECT VERSION();SELECT NOW()"
Enter password: ******
+------------+
| VERSION() |
+------------+
| 5.0.19-log |
+------------+
+---------------------+
| NOW() |
+---------------------+
| 2006-01-05 21:19:04 |
+---------------------+

The `--execute' or `-e' option may also be used to pass commands in an
analogous fashion to the *Note `ndb_mgm':
mysql-cluster-programs-ndb-mgm. management client for MySQL Cluster.
See *Note mysql-cluster-multi-shutdown-restart::, for an example.

File: manual.info, Node: option-modifiers, Next: option-files, Prev: command-line-options, Up: program-options

5.2.3.2 Program Option Modifiers
................................

Some options are `boolean' and control behavior that can be turned on
or off. For example, the *Note `mysql': mysql. client supports a
`--column-names' option that determines whether or not to display a row
of column names at the beginning of query results. By default, this
option is enabled. However, you may want to disable it in some
instances, such as when sending the output of *Note `mysql': mysql. into
another program that expects to see only data and not an initial header
line.

To disable column names, you can specify the option using any of these
forms:

--disable-column-names
--skip-column-names
--column-names=0

The `--disable' and `--skip' prefixes and the `=0' suffix all have the
same effect: They turn the option off.

The `enabled' form of the option may be specified in any of these ways:

--column-names
--enable-column-names
--column-names=1

If an option is prefixed by `--loose', a program does not exit with an
error if it does not recognize the option, but instead issues only a
warning:

shell> mysql --loose-no-such-option
mysql: WARNING: unknown option '--no-such-option'

The `--loose' prefix can be useful when you run programs from multiple
installations of MySQL on the same machine and list options in an
option file, An option that may not be recognized by all versions of a
program can be given using the `--loose' prefix (or `loose' in an
option file). Versions of the program that recognize the option process
it normally, and versions that do not recognize it issue a warning and
ignore it.

*Note `mysqld': mysqld. enables a limit to be placed on how large
client programs can set dynamic system variables. To do this, use a
`--maximum' prefix with the variable name. For example,
`--maximum-query_cache_size=4M' prevents any client from making the
query cache size larger than 4MB.

File: manual.info, Node: option-files, Next: program-variables, Prev: option-modifiers, Up: program-options

5.2.3.3 Using Option Files
..........................

* Menu:

* option-file-options:: Command-Line Options that Affect Option-File Handling
* option-files-preconfigured:: Preconfigured Option Files

Most MySQL programs can read startup options from option files (also
sometimes called configuration files). Option files provide a
convenient way to specify commonly used options so that they need not
be entered on the command line each time you run a program. For the
MySQL server, MySQL provides a number of *Note preconfigured option
files: option-files-preconfigured.

To determine whether a program reads option files, invoke it with the
`--help' option. (For *Note `mysqld': mysqld, use `--verbose' and
`--help'.) If the program reads option files, the help message
indicates which files it looks for and which option groups it
recognizes.

*Note*:

Option files used with MySQL Cluster programs are covered in *Note
mysql-cluster-configuration::.

On Windows, MySQL programs read startup options from the following
files, in the specified order (top items are used first).

File Name Purpose
`WINDIR\my.ini', Global options
`WINDIR\my.cnf'
`C:\my.ini', Global options
`C:\my.cnf'
`INSTALLDIR\my.ini', Global options
`INSTALLDIR\my.cnf'
`defaults-extra-file' The file specified with
`--defaults-extra-file=PATH', if any

WINDIR represents the location of your Windows directory. This is
commonly `C:\WINDOWS'. You can determine its exact location from the
value of the `WINDIR' environment variable using the following command:

C:\> echo %WINDIR%

INSTALLDIR represents the MySQL installation directory. This is
typically `C:\PROGRAMDIR\MySQL\MySQL 5.0 Server' where PROGRAMDIR
represents the programs directory (usually `Program Files' on
English-language versions of Windows), when MySQL 5.0 has been
installed using the installation and configuration wizards. See *Note
mysql-config-wizard-starting::.

On Unix, Linux and Mac OS X, MySQL programs read startup options from
the following files, in the specified order (top items are used first).

File Name Purpose
`/etc/my.cnf' Global options
`SYSCONFDIR/my.cnf' Global options
`$MYSQL_HOME/my.cnf' Server-specific options
`defaults-extra-file' The file specified with
`--defaults-extra-file=PATH', if any
`~/.my.cnf' User-specific options

`~' represents the current user's home directory (the value of `$HOME').

SYSCONFDIR represents the directory specified with the `--sysconfdir'
option to `configure' when MySQL was built. By default, this is the
`etc' directory located under the compiled-in installation directory.
This location is used as of MySQL 5.0.21. (From 5.0.21 to 5.0.53, it
was read last, after `~/.my.cnf'.)

`MYSQL_HOME' is an environment variable containing the path to the
directory in which the server-specific `my.cnf' file resides. (This was
DATADIR prior to MySQL version 5.0.3.)

If `MYSQL_HOME' is not set and you start the server using the *Note
`mysqld_safe': mysqld-safe. program, *Note `mysqld_safe': mysqld-safe.
attempts to set `MYSQL_HOME' as follows:

* Let BASEDIR and DATADIR represent the path names of the MySQL base
directory and data directory, respectively.

* If there is a `my.cnf' file in DATADIR but not in BASEDIR, *Note
`mysqld_safe': mysqld-safe. sets `MYSQL_HOME' to DATADIR.

* Otherwise, if `MYSQL_HOME' is not set and there is no `my.cnf'
file in DATADIR, *Note `mysqld_safe': mysqld-safe. sets
`MYSQL_HOME' to BASEDIR.

In MySQL 5.0, use of DATADIR as the location for `my.cnf' is deprecated.

Typically, DATADIR is `/usr/local/mysql/data' for a binary installation
or `/usr/local/var' for a source installation. Note that this is the
data directory location that was specified at configuration time, not
the one specified with the `--datadir' option when *Note `mysqld':
mysqld. starts. Use of `--datadir' at runtime has no effect on where
the server looks for option files, because it looks for them before
processing any options.

MySQL looks for option files in the order just described and reads any
that exist. If an option file that you want to use does not exist,
create it with a plain text editor.

If multiple instances of a given option are found, the last instance
takes precedence. There is one exception: For *Note `mysqld': mysqld,
the _first_ instance of the `--user' option is used as a security
precaution, to prevent a user specified in an option file from being
overridden on the command line.

*Note*:

On Unix platforms, MySQL ignores configuration files that are
world-writable. This is intentional as a security measure.

Any long option that may be given on the command line when running a
MySQL program can be given in an option file as well. To get the list
of available options for a program, run it with the `--help' option.

The syntax for specifying options in an option file is similar to
command-line syntax (see *Note command-line-options::). However, in an
option file, you omit the leading two dashes from the option name and
you specify only one option per line. For example, `--quick' and
`--host=localhost' on the command line should be specified as `quick'
and `host=localhost' on separate lines in an option file. To specify an
option of the form `--loose-OPT_NAME' in an option file, write it as
`loose-OPT_NAME'.

Empty lines in option files are ignored. Nonempty lines can take any of
the following forms:

* `#COMMENT', `;COMMENT'

Comment lines start with ``#'' or ``;''. A ``#'' comment can start
in the middle of a line as well.

* `[GROUP]'

GROUP is the name of the program or group for which you want to
set options. After a group line, any option-setting lines apply to
the named group until the end of the option file or another group
line is given.

* `OPT_NAME'

This is equivalent to `--OPT_NAME' on the command line.

* `OPT_NAME=VALUE'

This is equivalent to `--OPT_NAME=VALUE' on the command line. In
an option file, you can have spaces around the ``='' character,
something that is not true on the command line. You can optionally
enclose the value within single quotation marks or double
quotation marks, which is useful if the value contains a ``#''
comment character.

Leading and trailing spaces are automatically deleted from option names
and values.

You can use the escape sequences ``\b'', ``\t'', ``\n'', ``\r'',
``\\'', and ``\s'' in option values to represent the backspace, tab,
newline, carriage return, backslash, and space characters. The escaping
rules in option files are:

* If a backslash is followed by a valid escape sequence character,
the sequence is converted to the character represented by the
sequence. For example, ``\s'' is converted to a space.

* If a backslash is not followed by a valid escape sequence
character, it remains unchanged. For example, ``\S'' is retained
as is.

The preceding rules mean that a literal backslash can be given as
``\\'', or as ``\'' if it is not followed by a valid escape sequence
character.

The rules for escape sequences in option files differ slightly from the
rules for escape sequences in string literals in SQL statements. In the
latter context, if `X' is not a value escape sequence character, ``\X''
becomes `X' rather than ``\X''. See *Note string-syntax::.

The escaping rules for option file values are especially pertinent for
Windows path names, which use ``\'' as a path name separator. A
separator in a Windows path name must be written as ``\\'' if it is
followed by an escape sequence character. It can be written as ``\\'' or
``\'' if it is not. Alternatively, ``/'' may be used in Windows path
names and will be treated as ``\''. Suppose that you want to specify a
base directory of `C:\Program Files\MySQL\MySQL Server 5.0' in an
option file. This can be done several ways. Some examples:

basedir="C:\Program Files\MySQL\MySQL Server 5.0"
basedir="C:\\Program Files\\MySQL\\MySQL Server 5.0"
basedir="C:/Program Files/MySQL/MySQL Server 5.0"
basedir=C:\\Program\sFiles\\MySQL\\MySQL\sServer\s5.0

If an option group name is the same as a program name, options in the
group apply specifically to that program. For example, the `[mysqld]'
and `[mysql]' groups apply to the *Note `mysqld': mysqld. server and the
*Note `mysql': mysql. client program, respectively.

The `[client]' option group is read by all client programs (but _not_ by
*Note `mysqld': mysqld.). This enables you to specify options that
apply to all clients. For example, `[client]' is the perfect group to
use to specify the password that you use to connect to the server. (But
make sure that the option file is readable and writable only by
yourself, so that other people cannot find out your password.) Be sure
not to put an option in the `[client]' group unless it is recognized by
_all_ client programs that you use. Programs that do not understand the
option quit after displaying an error message if you try to run them.

Here is a typical global option file:

[client]
port=3306
socket=/tmp/mysql.sock

[mysqld]
port=3306
socket=/tmp/mysql.sock
key_buffer_size=16M
max_allowed_packet=8M

[mysqldump]
quick

The preceding option file uses `VAR_NAME=VALUE' syntax for the lines
that set the `key_buffer_size' and `max_allowed_packet' variables.

Here is a typical user option file:

[client]
# The following password will be sent to all standard MySQL clients
password="my_password"

[mysql]
no-auto-rehash
connect_timeout=2

[mysqlhotcopy]
interactive-timeout

If you want to create option groups that should be read by *Note
`mysqld': mysqld. servers from a specific MySQL release series only,
you can do this by using groups with names of `[mysqld-4.1]',
`[mysqld-5.0]', and so forth. The following group indicates that the
`--new' option should be used only by MySQL servers with 5.0.x version
numbers:

[mysqld-5.0]
new

Beginning with MySQL 5.0.4, it is possible to use `!include' directives
in option files to include other option files and `!includedir' to
search specific directories for option files. For example, to include
the `/home/mydir/myopt.cnf' file, use the following directive:

!include /home/mydir/myopt.cnf

To search the `/home/mydir' directory and read option files found
there, use this directive:

!includedir /home/mydir

There is no guarantee about the order in which the option files in the
directory will be read.

*Note*:

Currently, any files to be found and included using the `!includedir'
directive on Unix operating systems _must_ have file names ending in
`.cnf'. On Windows, this directive checks for files with the `.ini' or
`.cnf' extension.

Write the contents of an included option file like any other option
file. That is, it should contain groups of options, each preceded by a
`[GROUP]' line that indicates the program to which the options apply.

While an included file is being processed, only those options in groups
that the current program is looking for are used. Other groups are
ignored. Suppose that a `my.cnf' file contains this line:

!include /home/mydir/myopt.cnf

And suppose that `/home/mydir/myopt.cnf' looks like this:

[mysqladmin]
force

[mysqld]
key_buffer_size=16M

If `my.cnf' is processed by *Note `mysqld': mysqld, only the `[mysqld]'
group in `/home/mydir/myopt.cnf' is used. If the file is processed by
*Note `mysqladmin': mysqladmin, only the `[mysqldamin]' group is used.
If the file is processed by any other program, no options in
`/home/mydir/myopt.cnf' are used.

The `!includedir' directive is processed similarly except that all
option files in the named directory are read.

File: manual.info, Node: option-file-options, Next: option-files-preconfigured, Prev: option-files, Up: option-files

5.2.3.4 Command-Line Options that Affect Option-File Handling
.............................................................

Most MySQL programs that support option files handle the following
options. They affect option-file handling, so they must be given on the
command line and not in an option file. To work properly, each of
these options must immediately follow the command name, with these
exceptions:

* `--print-defaults' may be used immediately after `--defaults-file'
or `--defaults-extra-file'.

* On Windows, if the `--defaults-file' and `--install' options are
given, `--install' option must be first. See *Note
windows-start-service::.

When specifying file names, you should avoid the use of the ``~'' shell
metacharacter because it might not be interpreted as you expect.

* `--defaults-extra-file=FILE_NAME'

Read this option file after the global option file but (on Unix)
before the user option file. As of MySQL 5.0.6, if the file does
not exist or is otherwise inaccessible, the program exits with an
error. FILE_NAME is the full path name to the file.

* `--defaults-file=FILE_NAME'

Use only the given option file. If the file does not exist or is
otherwise inaccessible, the program exits with an error.
FILE_NAME is the full path name to the file.

* `--defaults-group-suffix=STR'

If this option is given, the program reads not only its usual
option groups, but also groups with the usual names and a suffix
of STR. For example, the *Note `mysql': mysql. client normally
reads the `[client]' and `[mysql]' groups. If the
`--defaults-group-suffix=_other' option is given, *Note `mysql':
mysql. also reads the `[client_other]' and `[mysql_other]' groups.
This option was added in MySQL 5.0.10.

* `--no-defaults'

Do not read any option files. If a program does not start because
it is reading unknown options from an option file, `--no-defaults'
can be used to prevent the program from reading them.

* `--print-defaults'

Print the program name and all options that it gets from option
files.

File: manual.info, Node: option-files-preconfigured, Prev: option-file-options, Up: option-files

5.2.3.5 Preconfigured Option Files
..................................

MySQL provides a number of preconfigured option files that can be used
as a basis for tuning the MySQL server. Look for files such as
`my-small.cnf', `my-medium.cnf', `my-large.cnf', and `my-huge.cnf',
which are sample option files for small, medium, large, and very large
systems. On Windows, the extension is `.ini' rather than `.cnf'.

*Note*:

On Windows, the `.ini' or `.cnf' option file extension might not be
displayed.

For a binary distribution, look for the files in or under your
installation directory. If you have a source distribution, look in the
`support-files' directory. You can rename a copy of a sample file and
place it in the appropriate location for use as a base configuration
file. Regarding names and appropriate location, see the general
information provided in *Note option-files::.

File: manual.info, Node: program-variables, Next: option-defaults-equals, Prev: option-files, Up: program-options

5.2.3.6 Using Options to Set Program Variables
..............................................

Many MySQL programs have internal variables that can be set at runtime
using the *Note `SET': set-option. statement. See *Note set-option::,
and *Note using-system-variables::.

Most of these program variables also can be set at server startup by
using the same syntax that applies to specifying program options. For
example, *Note `mysql': mysql. has a `max_allowed_packet' variable that
controls the maximum size of its communication buffer. To set the
`max_allowed_packet' variable for *Note `mysql': mysql. to a value of
16MB, use either of the following commands:

shell> mysql --max_allowed_packet=16777216
shell> mysql --max_allowed_packet=16M

The first command specifies the value in bytes. The second specifies
the value in megabytes. For variables that take a numeric value, the
value can be given with a suffix of `K', `M', or `G' (either uppercase
or lowercase) to indicate a multiplier of 1024, 1024^2 or 1024^3. (For
example, when used to set `max_allowed_packet', the suffixes indicate
units of kilobytes, megabytes, or gigabytes.)

In an option file, variable settings are given without the leading
dashes:

[mysql]
max_allowed_packet=16777216

Or:

[mysql]
max_allowed_packet=16M

If you like, underscores in a variable name can be specified as dashes.
The following option groups are equivalent. Both set the size of the
server's key buffer to 512MB:

[mysqld]
key_buffer_size=512M

[mysqld]
key-buffer-size=512M

A variable can be specified by writing it in full or as any unambiguous
prefix. For example, the `max_allowed_packet' variable can be set for
*Note `mysql': mysql. as `--max_a', but not as `--max' because the
latter is ambiguous:

shell> mysql --max=1000000
mysql: ambiguous option '--max=1000000' (max_allowed_packet, max_join_size)

Be aware that the use of variable prefixes can cause problems in the
event that new variables are implemented for a program. A prefix that
is unambiguous now might become ambiguous in the future.

Suffixes for specifying a value multiplier can be used when setting a
variable at server startup, but not to set the value with *Note `SET':
set-option. at runtime. On the other hand, with *Note `SET':
set-option. you can assign a variable's value using an expression,
which is not true when you set a variable at server startup. For
example, the first of the following lines is legal at server startup,
but the second is not:

shell> mysql --max_allowed_packet=16M
shell> mysql --max_allowed_packet=16*1024*1024

Conversely, the second of the following lines is legal at runtime, but
the first is not:

mysql> SET GLOBAL max_allowed_packet=16M;
mysql> SET GLOBAL max_allowed_packet=16*1024*1024;

*Note*:

Before MySQL 4.0.2, the only syntax for setting program variables was
`--set-variable=OPTION=VALUE' (or `set-variable=OPTION=VALUE' in option
files). Underscores cannot be given as dashes, and the variable name
must be specified in full. This syntax still is recognized, but is now
deprecated and is removed in MySQL 5.5.

File: manual.info, Node: option-defaults-equals, Prev: program-variables, Up: program-options

5.2.3.7 Option Defaults, Options Expecting Values, and the `=' Sign
...................................................................

By convention, long forms of options that assign a value are written
with an equals (`=') sign, like this:

shell> mysql --host=tonfisk --user=jon

For options that require a value (that is, not having a default value),
the equal sign is not required, and so the following is also valid:

shell> mysql --host tonfisk --user jon

In both cases, the *Note `mysql': mysql. client attempts to connect to
a MySQL server running on the host named `tonfisk' using an account
with the user name `jon'.

Due to this behavior, problems can occasionally arise when no value is
provided for an option that expects one. Consider the following
example, where a user connects to a MySQL server running on host
`tonfisk' as user `jon':

shell> mysql --host 85.224.35.45 --user jon
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.0.93 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> SELECT CURRENT_USER();
+----------------+
| CURRENT_USER() |
+----------------+
| jon@% |
+----------------+
1 row in set (0.00 sec)

Omitting the required value for one of these option yields an error,
such as the one shown here:

shell> mysql --host 85.224.35.45 --user
`mysql: option '--user' requires an argument'

In this case, *Note `mysql': mysql. was unable to find a value
following the `--user' option because nothing came after it on the
command line. However, if you omit the value for an option that is
_not_ the last option to be used, you obtain a different error that you
may not be expecting:

shell> mysql --host --user jon
`ERROR 2005 (HY000): Unknown MySQL server host '--user' (1)'

Because *Note `mysql': mysql. assumes that any string following
`--host' on the command line is a host name, `--host' `--user' is
interpreted as `--host=--user', and the client attempts to connect to a
MySQL server running on a host named `--user'.

Options having default values always require an equal sign when
assigning a value; failing to do so causes an error. For example, the
MySQL server `--log-error' option has the default value `HOST_NAME.err',
where HOST_NAME is the name of the host on which MySQL is running.
Assume that you are running MySQL on a computer whose host name is
`tonfisk', and consider the following invocation of *Note
`mysqld_safe': mysqld-safe.:

shell> mysqld_safe &
[1] 11699
shell> 080112 12:53:40 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.
080112 12:53:40 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var
shell>

After shutting down the server, restart it as follows:

shell> mysqld_safe --log-error &
[1] 11699
shell> 080112 12:53:40 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.
080112 12:53:40 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var
shell>

The result is the same, since `--log-error' is not followed by anything
else on the command line, and it supplies its own default value. (The
`&' character tells the operating system to run MySQL in the
background; it is ignored by MySQL itself.) Now suppose that you wish
to log errors to a file named `my-errors.err'. You might try starting
the server with `--log-error my-errors', but this does not have the
intended effect, as shown here:

shell> mysqld_safe --log-error my-errors &
[1] 31357
shell> 080111 22:53:31 mysqld_safe Logging to '/usr/local/mysql/var/tonfisk.err'.
080111 22:53:32 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var
080111 22:53:34 mysqld_safe mysqld from pid file /usr/local/mysql/var/tonfisk.pid ended

[1]+ Done ./mysqld_safe --log-error my-errors

The server attempted to start using `/usr/local/mysql/var/tonfisk.err'
as the error log, but then shut down. Examining the last few lines of
this file shows the reason:

shell> tail /usr/local/mysql/var/tonfisk.err
080111 22:53:32 InnoDB: Started; log sequence number 0 46409
`/usr/local/mysql/libexec/mysqld: Too many arguments (first extra is 'my-errors').
Use --verbose --help to get a list of available options'
080111 22:53:32 `[ERROR] Aborting'

080111 22:53:32 InnoDB: Starting shutdown...
080111 22:53:34 InnoDB: Shutdown completed; log sequence number 0 46409
080111 22:53:34 [Note] /usr/local/mysql/libexec/mysqld: Shutdown complete

080111 22:53:34 mysqld_safe mysqld from pid file /usr/local/mysql/var/tonfisk.pid ended

Because the `--log-error' option supplies a default value, you must use
an equal sign to assign a different value to it, as shown here:

shell> mysqld_safe --log-error=my-errors &
[1] 31437
shell> 080111 22:54:15 mysqld_safe Logging to '/usr/local/mysql/var/my-errors.err'.
080111 22:54:15 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var

shell>

Now the server has been started successfully, and is logging errors to
the file `/usr/local/mysql/var/my-errors.err'.

Similar issues can arise when specifying option values in option files.
For example, consider a `my.cnf' file that contains the following:

[mysql]

host
user

When the *Note `mysql': mysql. client reads this file, these entries
are parsed as `--host' `--user' or `--host=--user', with the result
shown here:

shell> mysql
`ERROR 2005 (HY000): Unknown MySQL server host '--user' (1)'

However, in option files, an equal sign is not assumed. Suppose the
`my.cnf' file is as shown here:

[mysql]

user jon

Trying to start *Note `mysql': mysql. in this case causes a different
error:

shell> mysql
`mysql: unknown option '--user jon''

A similar error would occur if you were to write `host tonfisk' in the
option file rather than `host=tonfisk'. Instead, you must use the equal
sign:

[mysql]

user=jon

shell> mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.0.93 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> SELECT USER();
+---------------+
| USER() |
+---------------+
| jon@localhost |
+---------------+
1 row in set (0.00 sec)

This is not the same behavior as with the command line, where the equal
sign is not required:

shell> mysql --user jon --host tonfisk
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.0.93 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> SELECT USER();
+---------------+
| USER() |
+---------------+
| jon@tonfisk |
+---------------+
1 row in set (0.00 sec)

File: manual.info, Node: setting-environment-variables, Prev: program-options, Up: programs-using

5.2.4 Setting Environment Variables
-----------------------------------

Environment variables can be set at the command prompt to affect the
current invocation of your command processor, or set permanently to
affect future invocations. To set a variable permanently, you can set
it in a startup file or by using the interface provided by your system
for this purpose. Consult the documentation for your command
interpreter for specific details. *Note environment-variables::, lists
all environment variables that affect MySQL program operation.

To specify a value for an environment variable, use the syntax
appropriate for your command processor. For example, on Windows or
NetWare, you can set the `USER' variable to specify your MySQL account
name. To do so, use this syntax:

SET USER=YOUR_NAME

The syntax on Unix depends on your shell. Suppose that you want to
specify the TCP/IP port number using the `MYSQL_TCP_PORT' variable.
Typical syntax (such as for `sh', `bash', `zsh', and so on) is as
follows:

MYSQL_TCP_PORT=3306
export MYSQL_TCP_PORT

The first command sets the variable, and the `export' command exports
the variable to the shell environment so that its value becomes
accessible to MySQL and other processes.

For `csh' and `tcsh', use `setenv' to make the shell variable available
to the environment:

setenv MYSQL_TCP_PORT 3306

The commands to set environment variables can be executed at your
command prompt to take effect immediately, but the settings persist
only until you log out. To have the settings take effect each time you
log in, use the interface provided by your system or place the
appropriate command or commands in a startup file that your command
interpreter reads each time it starts.

On Windows, you can set environment variables using the System Control
Panel (under Advanced).

On Unix, typical shell startup files are `.bashrc' or `.bash_profile'
for `bash', or `.tcshrc' for `tcsh'.

Suppose that your MySQL programs are installed in
`/usr/local/mysql/bin' and that you want to make it easy to invoke
these programs. To do this, set the value of the `PATH' environment
variable to include that directory. For example, if your shell is
`bash', add the following line to your `.bashrc' file:

PATH=${PATH}:/usr/local/mysql/bin

`bash' uses different startup files for login and nonlogin shells, so
you might want to add the setting to `.bashrc' for login shells and to
`.bash_profile' for nonlogin shells to make sure that `PATH' is set
regardless.

If your shell is `tcsh', add the following line to your `.tcshrc' file:

setenv PATH ${PATH}:/usr/local/mysql/bin

If the appropriate startup file does not exist in your home directory,
create it with a text editor.

After modifying your `PATH' setting, open a new console window on
Windows or log in again on Unix so that the setting goes into effect.

File: manual.info, Node: programs-server, Next: programs-installation, Prev: programs-using, Up: programs

5.3 MySQL Server and Server-Startup Programs
============================================

* Menu:

* mysqld:: `mysqld' --- The MySQL Server
* mysqld-safe:: `mysqld_safe' --- MySQL Server Startup Script
* mysql-server:: `mysql.server' --- MySQL Server Startup Script
* mysqld-multi:: `mysqld_multi' --- Manage Multiple MySQL Servers

This section describes *Note `mysqld': mysqld, the MySQL server, and
several programs that are used to start the server.

File: manual.info, Node: mysqld, Next: mysqld-safe, Prev: programs-server, Up: programs-server

5.3.1 `mysqld' -- The MySQL Server
----------------------------------

*Note `mysqld': mysqld, also known as MySQL Server, is the main program
that does most of the work in a MySQL installation. MySQL Server
manages access to the MySQL data directory that contains databases and
tables. The data directory is also the default location for other
information such as log files and status files.

When MySQL server starts, it listens for network connections from
client programs and manages access to databases on behalf of those
clients.

The *Note `mysqld': mysqld. program has many options that can be
specified at startup. For a complete list of options, run this command:

shell> mysqld --verbose --help

MySQL Server also has a set of system variables that affect its
operation as it runs. System variables can be set at server startup,
and many of them can be changed at runtime to effect dynamic server
reconfiguration. MySQL Server also has a set of status variables that
provide information about its operation. You can monitor these status
variables to access runtime performance characteristics.

For a full description of MySQL Server command options, system
variables, and status variables, see *Note mysqld-server::. For
information about installing MySQL and setting up the initial
configuration, see *Note installing::.

File: manual.info, Node: mysqld-safe, Next: mysql-server, Prev: mysqld, Up: programs-server

5.3.2 `mysqld_safe' -- MySQL Server Startup Script
--------------------------------------------------

*Note `mysqld_safe': mysqld-safe. is the recommended way to start a
*Note `mysqld': mysqld. server on Unix and NetWare. *Note
`mysqld_safe': mysqld-safe. adds some safety features such as
restarting the server when an error occurs and logging runtime
information to an error log file. NetWare-specific behaviors are listed
later in this section.

*Note*:

To preserve backward compatibility with older versions of MySQL, MySQL
binary distributions still include `safe_mysqld' as a symbolic link to
*Note `mysqld_safe': mysqld-safe. However, you should not rely on this
because it is removed as of MySQL 5.1.

By default, *Note `mysqld_safe': mysqld-safe. before MySQL 5.0.27 tries
to start an executable named `mysqld-max' if it exists, and *Note
`mysqld': mysqld. otherwise. Be aware of the implications of this
behavior:

* On Linux, the `MySQL-Max' RPM relies on this *Note `mysqld_safe':
mysqld-safe. behavior. The RPM installs an executable named
`mysqld-max', which causes *Note `mysqld_safe': mysqld-safe. to
automatically use that executable rather than *Note `mysqld':
mysqld. from that point on.

* If you install a MySQL-Max distribution that includes a server
named `mysqld-max', and then upgrade later to a non-Max version of
MySQL, *Note `mysqld_safe': mysqld-safe. will still attempt to run
the old `mysqld-max' server. If you perform such an upgrade, you
should manually remove the old `mysqld-max' server to ensure that
*Note `mysqld_safe': mysqld-safe. runs the new *Note `mysqld':
mysqld. server.

To override the default behavior and specify explicitly the name of the
server you want to run, specify a `--mysqld' or `--mysqld-version'
option to *Note `mysqld_safe': mysqld-safe. You can also use `--ledir'
to indicate the directory where *Note `mysqld_safe': mysqld-safe.
should look for the server.

Many of the options to *Note `mysqld_safe': mysqld-safe. are the same
as the options to *Note `mysqld': mysqld. See *Note server-options::.

Options unknown to *Note `mysqld_safe': mysqld-safe. are passed to
*Note `mysqld': mysqld. if they are specified on the command line, but
ignored if they are specified in the `[mysqld_safe]' group of an option
file. See *Note option-files::.

*Note `mysqld_safe': mysqld-safe. reads all options from the
`[mysqld]', `[server]', and `[mysqld_safe]' sections in option files.
For example, if you specify a `[mysqld]' section like this, *Note
`mysqld_safe': mysqld-safe. will find and use the `--log-error' option:

[mysqld]
log-error=error.log

For backward compatibility, *Note `mysqld_safe': mysqld-safe. also
reads `[safe_mysqld]' sections, although you should rename such
sections to `[mysqld_safe]' in MySQL 5.0 installations.

*Note `mysqld_safe': mysqld-safe. supports the following options. It
also reads option files and supports the options for processing them
described at *Note option-file-options::.

*`mysqld_safe' Options*

Format Option File Description IntroductionDeprecatedRemoved
-autoclose autoclose On NetWare, mysqld_safe
provides a screen presence
-basedir=pathbasedir The path to the MySQL
installation directory
-core-file-size=sizecore-file-sizeThe size of the core file
that mysqld should be able
to create
-datadir=pathdatadir The path to the data
directory
-defaults-extra-file=pathdefaults-extra-fileThe name of an option file
to be read in addition to
the usual option files
-defaults-file=file_namedefaults-fileThe name of an option file
to be read instead of the
usual option files
-help Display a help message and 5.0.3
exit
-ledir=path ledir Use this option to indicate
the path name to the
directory where the server
is located
-log-error=file_namelog-error Write the error log to the
given file
-mysqld=prog_namemysqld The name of the server
program (in the ledir
directory) that you want to
start
-mysqld-version=suffixmysqld-versionThis option is similar to
the -mysqld option, but you
specify only the suffix for
the server program name
-nice=prioritynice Use the nice program to set
the server's scheduling
priority to the given value
-no-defaultsno-defaults Do not read any option files
-open-files-limit=countopen-files-limitThe number of files that
mysqld should be able to open
-pid-file=file_namepid-file=file_nameThe path name of the process
ID file
-port=numberport The port number that the
server should use when
listening for TCP/IP
connections
-skip-kill-mysqldskip-kill-mysqldDo not try to kill stray
mysqld processes
-socket=pathsocket The Unix socket file that
the server should use when
listening for local
connections
-timezone=timezonetimezone Set the TZ time zone
environment variable to the
given option value
-user={user_name|user_id}user Run the mysqld server as the
user having the name
user_name or the numeric
user ID user_id

* `--help'

Display a help message and exit. (Added in MySQL 5.0.3)

* `--autoclose'

(NetWare only) On NetWare, *Note `mysqld_safe': mysqld-safe.
provides a screen presence. When you unload (shut down) the *Note
`mysqld_safe': mysqld-safe. NLM, the screen does not by default go
away. Instead, it prompts for user input:

*<NLM has terminated; Press any key to close the screen>*

If you want NetWare to close the screen automatically instead, use
the `--autoclose' option to *Note `mysqld_safe': mysqld-safe.

* `--basedir=PATH'

The path to the MySQL installation directory.

* `--core-file-size=SIZE'

The size of the core file that *Note `mysqld': mysqld. should be
able to create. The option value is passed to `ulimit -c'.

* `--datadir=PATH'

The path to the data directory.

* `--defaults-extra-file=PATH'

The name of an option file to be read in addition to the usual
option files. This must be the first option on the command line if
it is used. As of MySQL 5.0.6, if the file does not exist or is
otherwise inaccessible, the server will exit with an error.

* `--defaults-file=FILE_NAME'

The name of an option file to be read instead of the usual option
files. This must be the first option on the command line if it is
used.

* `--ledir=PATH'

If *Note `mysqld_safe': mysqld-safe. cannot find the server, use
this option to indicate the path name to the directory where the
server is located.

* `--log-error=FILE_NAME'

Write the error log to the given file. See *Note error-log::.

* `--mysqld=PROG_NAME'

The name of the server program (in the `ledir' directory) that you
want to start. This option is needed if you use the MySQL binary
distribution but have the data directory outside of the binary
distribution. If *Note `mysqld_safe': mysqld-safe. cannot find
the server, use the `--ledir' option to indicate the path name to
the directory where the server is located.

* `--mysqld-version=SUFFIX'

This option is similar to the `--mysqld' option, but you specify
only the suffix for the server program name. The basename is
assumed to be *Note `mysqld': mysqld. For example, if you use
`--mysqld-version=debug', *Note `mysqld_safe': mysqld-safe. starts
the *Note `mysqld-debug': mysqld. program in the `ledir'
directory. If the argument to `--mysqld-version' is empty, *Note
`mysqld_safe': mysqld-safe. uses *Note `mysqld': mysqld. in the
`ledir' directory.

* `--nice=PRIORITY'

Use the `nice' program to set the server's scheduling priority to
the given value.

* `--no-defaults'

Do not read any option files. This must be the first option on the
command line if it is used.

* `--open-files-limit=COUNT'

The number of files that *Note `mysqld': mysqld. should be able to
open. The option value is passed to `ulimit -n'. Note that you
need to start *Note `mysqld_safe': mysqld-safe. as `root' for this
to work properly!

* `--pid-file=FILE_NAME'

The path name of the process ID file.

* `--port=PORT_NUM'

The port number that the server should use when listening for
TCP/IP connections. The port number must be 1024 or higher unless
the server is started by the `root' system user.

* `--skip-kill-mysqld'

Do not try to kill stray *Note `mysqld': mysqld. processes at
startup. This option works only on Linux.

* `--socket=PATH'

The Unix socket file that the server should use when listening for
local connections.

* `--timezone=TIMEZONE'

Set the `TZ' time zone environment variable to the given option
value. Consult your operating system documentation for legal time
zone specification formats.

* `--user={USER_NAME|USER_ID}'

Run the *Note `mysqld': mysqld. server as the user having the name
USER_NAME or the numeric user ID USER_ID. (`User' in this context
refers to a system login account, not a MySQL user listed in the
grant tables.)

If you execute *Note `mysqld_safe': mysqld-safe. with the
`--defaults-file' or `--defaults-extra-file' option to name an option
file, the option must be the first one given on the command line or the
option file will not be used. For example, this command will not use
the named option file:

mysql> mysqld_safe --port=PORT_NUM --defaults-file=FILE_NAME

Instead, use the following command:

mysql> mysqld_safe --defaults-file=FILE_NAME --port=PORT_NUM

The *Note `mysqld_safe': mysqld-safe. script is written so that it
normally can start a server that was installed from either a source or
a binary distribution of MySQL, even though these types of
distributions typically install the server in slightly different
locations. (See *Note installation-layouts::.) *Note `mysqld_safe':
mysqld-safe. expects one of the following conditions to be true:

* The server and databases can be found relative to the working
directory (the directory from which *Note `mysqld_safe':
mysqld-safe. is invoked). For binary distributions, *Note
`mysqld_safe': mysqld-safe. looks under its working directory for
`bin' and `data' directories. For source distributions, it looks
for `libexec' and `var' directories. This condition should be met
if you execute *Note `mysqld_safe': mysqld-safe. from your MySQL
installation directory (for example, `/usr/local/mysql' for a
binary distribution).

* If the server and databases cannot be found relative to the
working directory, *Note `mysqld_safe': mysqld-safe. attempts to
locate them by absolute path names. Typical locations are
`/usr/local/libexec' and `/usr/local/var'. The actual locations
are determined from the values configured into the distribution at
the time it was built. They should be correct if MySQL is
installed in the location specified at configuration time.

Because *Note `mysqld_safe': mysqld-safe. tries to find the server and
databases relative to its own working directory, you can install a
binary distribution of MySQL anywhere, as long as you run *Note
`mysqld_safe': mysqld-safe. from the MySQL installation directory:

shell> cd MYSQL_INSTALLATION_DIRECTORY
shell> bin/mysqld_safe &

If *Note `mysqld_safe': mysqld-safe. fails, even when invoked from the
MySQL installation directory, you can specify the `--ledir' and
`--datadir' options to indicate the directories in which the server and
databases are located on your system.

Normally, you should not edit the *Note `mysqld_safe': mysqld-safe.
script. Instead, configure *Note `mysqld_safe': mysqld-safe. by using
command-line options or options in the `[mysqld_safe]' section of a
`my.cnf' option file. In rare cases, it might be necessary to edit
*Note `mysqld_safe': mysqld-safe. to get it to start the server
properly. However, if you do this, your modified version of *Note
`mysqld_safe': mysqld-safe. might be overwritten if you upgrade MySQL
in the future, so you should make a copy of your edited version that
you can reinstall.

On NetWare, *Note `mysqld_safe': mysqld-safe. is a NetWare Loadable
Module (NLM) that is ported from the original Unix shell script. It
starts the server as follows:

1. Runs a number of system and option checks.

2. Runs a check on `MyISAM' tables.

3. Provides a screen presence for the MySQL server.

4. Starts *Note `mysqld': mysqld, monitors it, and restarts it if it
terminates in error.

5. Sends error messages from *Note `mysqld': mysqld. to the
`HOST_NAME.err' file in the data directory.

6. Sends *Note `mysqld_safe': mysqld-safe. screen output to the
`HOST_NAME.safe' file in the data directory.

File: manual.info, Node: mysql-server, Next: mysqld-multi, Prev: mysqld-safe, Up: programs-server

5.3.3 `mysql.server' -- MySQL Server Startup Script
---------------------------------------------------

MySQL distributions on Unix include a script named *Note
`mysql.server': mysql-server. It can be used on systems such as Linux
and Solaris that use System V-style run directories to start and stop
system services. It is also used by the Mac OS X Startup Item for MySQL.

*Note `mysql.server': mysql-server. can be found in the `support-files'
directory under your MySQL installation directory or in a MySQL source
distribution.

If you use the Linux server RPM package (`MySQL-server-VERSION.rpm'),
the *Note `mysql.server': mysql-server. script will be installed in the
`/etc/init.d' directory with the name `mysql'. You need not install it
manually. See *Note linux-installation-rpm::, for more information on
the Linux RPM packages.

Some vendors provide RPM packages that install a startup script under a
different name such as *Note `mysqld': mysqld.

If you install MySQL from a source distribution or using a binary
distribution format that does not install *Note `mysql.server':
mysql-server. automatically, you can install it manually. Instructions
are provided in *Note automatic-start::.

*Note `mysql.server': mysql-server. reads options from the
`[mysql.server]' and `[mysqld]' sections of option files. For backward
compatibility, it also reads `[mysql_server]' sections, although you
should rename such sections to `[mysql.server]' when using MySQL 5.0.

*Note `mysql.server': mysql-server. supports the following options.

* `--basedir=PATH'

The path to the MySQL installation directory.

* `--datadir=PATH'

The path to the MySQL data directory.

* `--pid-file=FILE_NAME'

The path name of the file in which the server should write its
process ID.

* `--service-startup-timeout=FILE_NAME'

How long in seconds to wait for confirmation of server startup. If
the server does not start within this time, *Note `mysql.server':
mysql-server. exits with an error. The default value is 900. A
value of 0 means not to wait at all for startup. Negative values
mean to wait forever (no timeout). This option was added in MySQL
5.0.40. Before that, a value of 900 is always used.

* `--use-mysqld_safe'

Use *Note `mysqld_safe': mysqld-safe. to start the server. This is
the default. This option was added in MySQL 5.0.4.

* `--use-manager'

Use Instance Manager to start the server. This option was added in
MySQL 5.0.4.

* `--user=USER_NAME'

The login user name to use for running *Note `mysqld': mysqld.
This option was added in MySQL 5.0.4.

File: manual.info, Node: mysqld-multi, Prev: mysql-server, Up: programs-server

5.3.4 `mysqld_multi' -- Manage Multiple MySQL Servers
-----------------------------------------------------

*Note `mysqld_multi': mysqld-multi. is designed to manage several *Note
`mysqld': mysqld. processes that listen for connections on different
Unix socket files and TCP/IP ports. It can start or stop servers, or
report their current status. The MySQL Instance Manager is an
alternative means of managing multiple servers (see *Note
instance-manager::).

*Note `mysqld_multi': mysqld-multi. searches for groups named
`[mysqldN]' in `my.cnf' (or in the file named by the `--config-file'
option). N can be any positive integer. This number is referred to in
the following discussion as the option group number, or GNR. Group
numbers distinguish option groups from one another and are used as
arguments to *Note `mysqld_multi': mysqld-multi. to specify which
servers you want to start, stop, or obtain a status report for.
Options listed in these groups are the same that you would use in the
`[mysqld]' group used for starting *Note `mysqld': mysqld. (See, for
example, *Note automatic-start::.) However, when using multiple
servers, it is necessary that each one use its own value for options
such as the Unix socket file and TCP/IP port number. For more
information on which options must be unique per server in a
multiple-server environment, see *Note multiple-servers::.

To invoke *Note `mysqld_multi': mysqld-multi, use the following syntax:

shell> mysqld_multi [OPTIONS] {start|stop|report} [GNR[,GNR] ...]

`start', `stop', and `report' indicate which operation to perform. You
can perform the designated operation for a single server or multiple
servers, depending on the GNR list that follows the option name. If
there is no list, *Note `mysqld_multi': mysqld-multi. performs the
operation for all servers in the option file.

Each GNR value represents an option group number or range of group
numbers. The value should be the number at the end of the group name in
the option file. For example, the GNR for a group named `[mysqld17]' is
`17'. To specify a range of numbers, separate the first and last numbers
by a dash. The GNR value `10-13' represents groups `[mysqld10]' through
`[mysqld13]'. Multiple groups or group ranges can be specified on the
command line, separated by commas. There must be no whitespace
characters (spaces or tabs) in the GNR list; anything after a whitespace
character is ignored.

This command starts a single server using option group `[mysqld17]':

shell> mysqld_multi start 17

This command stops several servers, using option groups `[mysqld8]' and
`[mysqld10]' through `[mysqld13]':

shell> mysqld_multi stop 8,10-13

For an example of how you might set up an option file, use this command:

shell> mysqld_multi --example

As of MySQL 5.0.42, *Note `mysqld_multi': mysqld-multi. searches for
option files as follows:

* With `--no-defaults', no option files are read.

* With `--defaults-file=FILE_NAME', only the named file is read.

* Otherwise, option files in the standard list of locations are
read, including any file named by the
`--defaults-extra-file=FILE_NAME' option, if one is given. (If the
option is given multiple times, the last value is used.)

Before MySQL 5.0.42, the preceding options are not recognized. Files
in the standard locations are read, and any file named by the
`--config-file=FILE_NAME' option, if one is given. A file named by
`--config-file' is read only for `[mysqldN]' option groups, not the
`[mysqld_multi]' group.

Option files read are searched for `[mysqld_multi]' and `[mysqldN]'
option groups. The `[mysqld_multi]' group can be used for options to
*Note `mysqld_multi': mysqld-multi. itself. `[mysqldN]' groups can be
used for options passed to specific *Note `mysqld': mysqld. instances.

As of MySQL 5.0.82, the `[mysqld]' or `[mysqld_safe]' groups can be
used for common options read by all instances of *Note `mysqld':
mysqld. or *Note `mysqld_safe': mysqld-safe. You can specify a
`--defaults-file=FILE_NAME' option to use a different configuration
file for that instance, in which case the `[mysqld]' or `[mysqld_safe]'
groups from that file will be used for that instance. Before MySQL
5.0.82, some versions of *Note `mysqld_multi': mysqld-multi. pass the
`--no-defaults' options to instances, so these techniques are
inapplicable.

*Note `mysqld_multi': mysqld-multi. supports the following options.

* `--help'

Display a help message and exit.

* `--config-file=FILE_NAME'

As of MySQL 5.0.42, this option is deprecated. If given, it is
treated the same way as `--defaults-extra-file', described earlier.
`--config-file' is removed in MySQL 5.5.

Before MySQL 5.0.42, this option specifies the name of an extra
option file. It affects where *Note `mysqld_multi': mysqld-multi.
looks for `[mysqldN]' option groups. Without this option, all
options are read from the usual `my.cnf' file. The option does not
affect where *Note `mysqld_multi': mysqld-multi. reads its own
options, which are always taken from the `[mysqld_multi]' group in
the usual `my.cnf' file.

* `--example'

Display a sample option file.

* `--log=FILE_NAME'

Specify the name of the log file. If the file exists, log output
is appended to it.

* `--mysqladmin=PROG_NAME'

The *Note `mysqladmin': mysqladmin. binary to be used to stop
servers.

* `--mysqld=PROG_NAME'

The *Note `mysqld': mysqld. binary to be used. Note that you can
specify *Note `mysqld_safe': mysqld-safe. as the value for this
option also. If you use *Note `mysqld_safe': mysqld-safe. to start
the server, you can include the `mysqld' or `ledir' options in the
corresponding `[mysqldN]' option group. These options indicate the
name of the server that *Note `mysqld_safe': mysqld-safe. should
start and the path name of the directory where the server is
located. (See the descriptions for these options in *Note
mysqld-safe::.) Example:

[mysqld38]
mysqld = mysqld-debug
ledir = /opt/local/mysql/libexec

* `--no-log'

Print log information to `stdout' rather than to the log file. By
default, output goes to the log file.

* `--password=PASSWORD'

The password of the MySQL account to use when invoking *Note
`mysqladmin': mysqladmin. Note that the password value is not
optional for this option, unlike for other MySQL programs.

* `--silent'

Silent mode; disable warnings.

* `--tcp-ip'

Connect to each MySQL server through the TCP/IP port instead of
the Unix socket file. (If a socket file is missing, the server
might still be running, but accessible only through the TCP/IP
port.) By default, connections are made using the Unix socket
file. This option affects `stop' and `report' operations.

* `--user=USER_NAME'

The user name of the MySQL account to use when invoking *Note
`mysqladmin': mysqladmin.

* `--verbose'

Be more verbose.

* `--version'

Display version information and exit.

Some notes about *Note `mysqld_multi': mysqld-multi.:

* *Most important*: Before using *Note `mysqld_multi': mysqld-multi.
be sure that you understand the meanings of the options that are
passed to the *Note `mysqld': mysqld. servers and _why_ you would
want to have separate *Note `mysqld': mysqld. processes. Beware of
the dangers of using multiple *Note `mysqld': mysqld. servers with
the same data directory. Use separate data directories, unless you
_know_ what you are doing. Starting multiple servers with the same
data directory does _not_ give you extra performance in a threaded
system. See *Note multiple-servers::.

* *Important*:

Make sure that the data directory for each server is fully
accessible to the Unix account that the specific *Note `mysqld':
mysqld. process is started as. _Do not_ use the Unix ROOT account
for this, unless you _know_ what you are doing. See *Note
changing-mysql-user::.

* Make sure that the MySQL account used for stopping the *Note
`mysqld': mysqld. servers (with the *Note `mysqladmin':
mysqladmin. program) has the same user name and password for each
server. Also, make sure that the account has the `SHUTDOWN'
privilege. If the servers that you want to manage have different
user names or passwords for the administrative accounts, you might
want to create an account on each server that has the same user
name and password. For example, you might set up a common
`multi_admin' account by executing the following commands for each
server:

shell> mysql -u root -S /tmp/mysql.sock -p
Enter password:
mysql> GRANT SHUTDOWN ON *.*
-> TO 'multi_admin'@'localhost' IDENTIFIED BY 'multipass';

See *Note privilege-system::. You have to do this for each *Note
`mysqld': mysqld. server. Change the connection parameters
appropriately when connecting to each one. Note that the host name
part of the account name must permit you to connect as
`multi_admin' from the host where you want to run *Note
`mysqld_multi': mysqld-multi.

* The Unix socket file and the TCP/IP port number must be different
for every *Note `mysqld': mysqld. (Alternatively, if the host has
multiple network addresses, you can use `--bind-address' to cause
different servers to listen to different interfaces.)

* The `--pid-file' option is very important if you are using *Note
`mysqld_safe': mysqld-safe. to start *Note `mysqld': mysqld. (for
example, `--mysqld=mysqld_safe') Every *Note `mysqld': mysqld.
should have its own process ID file. The advantage of using *Note
`mysqld_safe': mysqld-safe. instead of *Note `mysqld': mysqld. is
that *Note `mysqld_safe': mysqld-safe. monitors its *Note
`mysqld': mysqld. process and restarts it if the process
terminates due to a signal sent using `kill -9' or for other
reasons, such as a segmentation fault. Please note that the *Note
`mysqld_safe': mysqld-safe. script might require that you start
it from a certain place. This means that you might have to change
location to a certain directory before running *Note
`mysqld_multi': mysqld-multi. If you have problems starting,
please see the *Note `mysqld_safe': mysqld-safe. script. Check
especially the lines:

----------------------------------------------------------------
MY_PWD=`pwd`
# Check if we are starting this relative (for the binary release)
if test -d $MY_PWD/data/mysql -a -f ./share/mysql/english/errmsg.sys -a \
-x ./bin/mysqld
----------------------------------------------------------------

The test performed by these lines should be successful, or you
might encounter problems. See *Note mysqld-safe::.

* You might want to use the `--user' option for *Note `mysqld':
mysqld, but to do this you need to run the *Note `mysqld_multi':
mysqld-multi. script as the Unix superuser (`root'). Having the
option in the option file doesn't matter; you just get a warning if
you are not the superuser and the *Note `mysqld': mysqld.
processes are started under your own Unix account.

The following example shows how you might set up an option file for use
with *Note `mysqld_multi': mysqld-multi. The order in which the *Note
`mysqld': mysqld. programs are started or stopped depends on the order
in which they appear in the option file. Group numbers need not form
an unbroken sequence. The first and fifth `[mysqldN]' groups were
intentionally omitted from the example to illustrate that you can have
`gaps' in the option file. This gives you more flexibility.

# This file should probably be in your home dir (~/.my.cnf)
# or /etc/my.cnf
# Version 2.1 by Jani Tolonen

[mysqld_multi]
mysqld = /usr/local/bin/mysqld_safe
mysqladmin = /usr/local/bin/mysqladmin
user = multi_admin
password = multipass

[mysqld2]
socket = /tmp/mysql.sock2
port = 3307
pid-file = /usr/local/mysql/var2/hostname.pid2
datadir = /usr/local/mysql/var2
language = /usr/local/share/mysql/english
user = john

[mysqld3]
socket = /tmp/mysql.sock3
port = 3308
pid-file = /usr/local/mysql/var3/hostname.pid3
datadir = /usr/local/mysql/var3
language = /usr/local/share/mysql/swedish
user = monty

[mysqld4]
socket = /tmp/mysql.sock4
port = 3309
pid-file = /usr/local/mysql/var4/hostname.pid4
datadir = /usr/local/mysql/var4
language = /usr/local/share/mysql/estonia
user = tonu

[mysqld6]
socket = /tmp/mysql.sock6
port = 3311
pid-file = /usr/local/mysql/var6/hostname.pid6
datadir = /usr/local/mysql/var6
language = /usr/local/share/mysql/japanese
user = jani

See *Note option-files::.

File: manual.info, Node: programs-installation, Next: programs-client, Prev: programs-server, Up: programs

5.4 MySQL Installation-Related Programs
=======================================

* Menu:

* comp-err:: `comp_err' --- Compile MySQL Error Message File
* make-win-bin-dist:: `make_win_bin_dist' --- Package MySQL Distribution as ZIP Archive
* make-win-src-distribution:: `make_win_src_distribution' --- Create Source Distribution for Windows
* mysqlbug:: `mysqlbug' --- Generate Bug Report
* mysql-fix-privilege-tables:: `mysql_fix_privilege_tables' --- Upgrade MySQL System Tables
* mysql-install-db:: `mysql_install_db' --- Initialize MySQL Data Directory
* mysql-secure-installation:: `mysql_secure_installation' --- Improve MySQL Installation Security
* mysql-tzinfo-to-sql:: `mysql_tzinfo_to_sql' --- Load the Time Zone Tables
* mysql-upgrade:: `mysql_upgrade' --- Check Tables for MySQL Upgrade

The programs in this section are used when installing or upgrading
MySQL.

File: manual.info, Node: comp-err, Next: make-win-bin-dist, Prev: programs-installation, Up: programs-installation

5.4.1 `comp_err' -- Compile MySQL Error Message File
----------------------------------------------------

*Note `comp_err': comp-err. creates the `errmsg.sys' file that is used
by *Note `mysqld': mysqld. to determine the error messages to display
for different error codes. *Note `comp_err': comp-err. normally is run
automatically when MySQL is built. It compiles the `errmsg.sys' file
from the plaintext file located at `sql/share/errmsg.txt' in MySQL
source distributions.

*Note `comp_err': comp-err. also generates `mysqld_error.h',
`mysqld_ername.h', and `sql_state.h' header files.

For more information about how error messages are defined, see the
MySQL Internals Manual.

Invoke *Note `comp_err': comp-err. like this:

shell> comp_err [OPTIONS]

*Note `comp_err': comp-err. supports the following options.

* `--help', `-?'

Display a help message and exit.

* `--charset=PATH', `-C PATH'

The character set directory. The default is
`../sql/share/charsets'.

* `--debug=DEBUG_OPTIONS', `-# DEBUG_OPTIONS'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:O,FILE_NAME''. The default is `'d:t:O,/tmp/comp_err.trace''.

* `--debug-info', `-T'

Print some debugging information when the program exits.

* `--header_file=FILE_NAME', `-H FILE_NAME'

The name of the error header file. The default is `mysqld_error.h'.

* `--in_file=FILE_NAME', `-F FILE_NAME'

The name of the input file. The default is
`../sql/share/errmsg.txt'.

* `--name_file=FILE_NAME', `-N FILE_NAME'

The name of the error name file. The default is `mysqld_ername.h'.

* `--out_dir=PATH', `-D PATH'

The name of the output base directory. The default is
`../sql/share/'.

* `--out_file=FILE_NAME', `-O FILE_NAME'

The name of the output file. The default is `errmsg.sys'.

* `--statefile=FILE_NAME', `-S FILE_NAME'

The name for the SQLSTATE header file. The default is
`sql_state.h'.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: make-win-bin-dist, Next: make-win-src-distribution, Prev: comp-err, Up: programs-installation

5.4.2 `make_win_bin_dist' -- Package MySQL Distribution as ZIP Archive
----------------------------------------------------------------------

This script is used on Windows after building a MySQL distribution from
source to create executable programs. It packages the binaries and
support files into a ZIP archive that can be unpacked at the location
where you want to install MySQL.

*Note `make_win_bin_dist': make-win-bin-dist. is a shell script, so you
must have Cygwin installed to use it.

This program's use is subject to change. Currently, you invoke it as
follows from the root directory of your source distribution:

shell> make_win_bin_dist [OPTIONS] PACKAGE_BASENAME [COPY_DEF ...]

The PACKAGE_BASENAME argument provides the basename for the resulting
ZIP archive. This name will be the name of the directory that results
from unpacking the archive.

Because you might want to include files of directories from other
builds, you can instruct this script to copy them in for you, using
COPY_DEF arguments, which have the form RELATIVE_DEST_NAME=SOURCE_NAME.

Example:

bin/mysqld-max.exe=../my-max-build/sql/release/mysqld.exe

If you specify a directory, the entire directory will be copied.

*Note `make_win_bin_dist': make-win-bin-dist. supports the following
options.

* `--debug'

Pack the debug binaries and produce an error if they were not
built.

* `--embedded'

Pack the embedded server and produce an error if it was not built.
The default is to pack it if it was built.

* `--exe-suffix=SUFFIX'

Add a suffix to the basename of the *Note `mysql': mysql. binary.
For example, a suffix of `-abc' produces a binary named
`mysqld-abc.exe'.

* `--no-debug'

Do not pack the debug binaries even if they were built.

* `--no-embedded'

Do not pack the embedded server even if it was built.

* `--only-debug'

Use this option when the target for this build was `Debug', and
you just want to replace the normal binaries with debug versions
(that is, do not use separate `debug' directories).

File: manual.info, Node: make-win-src-distribution, Next: mysqlbug, Prev: make-win-bin-dist, Up: programs-installation

5.4.3 `make_win_src_distribution' -- Create Source Distribution for Windows
---------------------------------------------------------------------------

*Note `make_win_src_distribution': make-win-src-distribution. creates a
Windows source package to be used on Windows systems. It is used after
you configure and build the source distribution on a Unix or Unix-like
system so that you have a server binary to work with. (See the
instructions at *Note windows-sourcetree-build::.)

Invoke *Note `make_win_src_distribution': make-win-src-distribution.
like this from the top-level directory of a MySQL source distribution:

shell> make_win_src_distribution [OPTIONS]

*Note `make_win_src_distribution': make-win-src-distribution.
understands the following options:

* `--help'

Display a help message and exit.

* `--debug'

Print information about script operations; do not create a package.

* `--dirname'

Directory name to copy files (intermediate).

* `--silent'

Do not print verbose list of files processed.

* `--suffix'

The suffix name for the package.

* `--tar'

Create a `.tar.gz' package instead of a `.zip' package.

* `--tmp'

Specify the temporary location.

File: manual.info, Node: mysqlbug, Next: mysql-fix-privilege-tables, Prev: make-win-src-distribution, Up: programs-installation

5.4.4 `mysqlbug' -- Generate Bug Report
---------------------------------------

This program enables you to generate a bug report and send it to Oracle
Corporation. It is a shell script and runs on Unix.

The normal way to report bugs is to visit `http://bugs.mysql.com/',
which is the address for our bugs database. This database is public and
can be browsed and searched by anyone. If you log in to the system, you
can enter new reports. If you have no Web access, you can generate a
bug report by using the *Note `mysqlbug': mysqlbug. script.

*Note `mysqlbug': mysqlbug. helps you generate a report by determining
much of the following information automatically, but if something
important is missing, please include it with your message. *Note
`mysqlbug': mysqlbug. can be found in the `scripts' directory (source
distribution) and in the `bin' directory under your MySQL installation
directory (binary distribution).

Invoke *Note `mysqlbug': mysqlbug. without arguments:

shell> mysqlbug

The script will place you in an editor with a copy of the report to be
sent. Edit the lines near the beginning that indicate the nature of the
problem. Then write the file to save your changes, quit the editor, and
*Note `mysqlbug': mysqlbug. will send the report by email.

File: manual.info, Node: mysql-fix-privilege-tables, Next: mysql-install-db, Prev: mysqlbug, Up: programs-installation

5.4.5 `mysql_fix_privilege_tables' -- Upgrade MySQL System Tables
-----------------------------------------------------------------

Some releases of MySQL introduce changes to the structure of the system
tables in the `mysql' database to add new privileges or support new
features. When you update to a new version of MySQL, you should update
your system tables as well to make sure that their structure is up to
date. Otherwise, there might be capabilities that you cannot take
advantage of.

*Note `mysql_fix_privilege_tables': mysql-fix-privilege-tables. is an
older script that previously was used to uprade the system tables in the
`mysql' database after a MySQL upgrade.

*Note*:

As of MySQL 5.0.19, *Note `mysql_fix_privilege_tables':
mysql-fix-privilege-tables. is superseded by *Note `mysql_upgrade':
mysql-upgrade, which should be used instead. See *Note mysql-upgrade::.

Before running *Note `mysql_fix_privilege_tables':
mysql-fix-privilege-tables, make a backup of your `mysql' database.

On Unix or Unix-like systems, update the system tables by running the
*Note `mysql_fix_privilege_tables': mysql-fix-privilege-tables. script:

shell> mysql_fix_privilege_tables

You must run this script while the server is running. It attempts to
connect to the server running on the local host as `root'. If your
`root' account requires a password, indicate the password on the
command line like this:

shell> mysql_fix_privilege_tables --password=ROOT_PASSWORD

The *Note `mysql_fix_privilege_tables': mysql-fix-privilege-tables.
script performs any actions necessary to convert your system tables to
the current format. You might see some `Duplicate column name' warnings
as it runs; you can ignore them.

After running the script, stop the server and restart it so that any
changes made to the system tables take effect.

On Windows systems, MySQL distributions include a
`mysql_fix_privilege_tables.sql' SQL script that you can run using the
*Note `mysql': mysql. client. For example, if your MySQL installation
is located at `C:\Program Files\MySQL\MySQL Server 5.0', the commands
look like this:

C:\> cd "C:\Program Files\MySQL\MySQL Server 5.0"
C:\> bin\mysql -u root -p mysql
mysql> SOURCE share/mysql_fix_privilege_tables.sql

*Note*:

Prior to version 5.0.38, this script is found in the `scripts'
directory.

The *Note `mysql': mysql. command will prompt you for the `root'
password; enter it when prompted.

If your installation is located in some other directory, adjust the
path names appropriately.

As with the Unix procedure, you might see some `Duplicate column name'
warnings as *Note `mysql': mysql. processes the statements in the
`mysql_fix_privilege_tables.sql' script; you can ignore them.

After running the script, stop the server and restart it.

File: manual.info, Node: mysql-install-db, Next: mysql-secure-installation, Prev: mysql-fix-privilege-tables, Up: programs-installation

5.4.6 `mysql_install_db' -- Initialize MySQL Data Directory
-----------------------------------------------------------

*Note `mysql_install_db': mysql-install-db. initializes the MySQL data
directory and creates the system tables that it contains, if they do
not exist.

To invoke *Note `mysql_install_db': mysql-install-db, use the following
syntax:

shell> mysql_install_db [OPTIONS]

Because the MySQL server, *Note `mysqld': mysqld, needs to access the
data directory when it runs later, you should either run *Note
`mysql_install_db': mysql-install-db. from the same account that will
be used for running *Note `mysqld': mysqld. or run it as `root' and use
the `--user' option to indicate the user name that *Note `mysqld':
mysqld. will run as. It might be necessary to specify other options
such as `--basedir' or `--datadir' if *Note `mysql_install_db':
mysql-install-db. does not use the correct locations for the
installation directory or data directory. For example:

shell> bin/mysql_install_db --user=mysql \
--basedir=/opt/mysql/mysql \
--datadir=/opt/mysql/mysql/data

*Note `mysql_install_db': mysql-install-db. needs to invoke *Note
`mysqld': mysqld. with the `--bootstrap' and `--skip-grant-tables'
options. If MySQL was configured with the `DISABLE_GRANT_OPTIONS'
(http://dev.mysql.com/doc/refman/5.5/en/source-configuration-options.html#option_cmake_disable_grant_options)
compiler flag, `--bootstrap' and `--skip-grant-tables' will be disabled
(see *Note source-configuration-options::). To handle this, set the
`MYSQLD_BOOTSTRAP' environment variable to the full path name of a
server that has all options enabled. *Note `mysql_install_db':
mysql-install-db. will use that server.

*Note `mysql_install_db': mysql-install-db. supports the following
options, which can be specified on the command line or in the
`[mysql_install_db]' and (if they are common to *Note `mysqld':
mysqld.) `[mysqld]' option file groups.

* `--basedir=PATH'

The path to the MySQL installation directory.

* `--force'

Cause *Note `mysql_install_db': mysql-install-db. to run even if
DNS does not work. In that case, grant table entries that normally
use host names will use IP addresses.

* `--datadir=PATH', `--ldata=PATH'

The path to the MySQL data directory.

* `--rpm'

For internal use. This option is used by RPM files during the
MySQL installation process.

* `--skip-name-resolve'

Use IP addresses rather than host names when creating grant table
entries. This option can be useful if your DNS does not work.

* `--srcdir=PATH'

For internal use. The directory under which *Note
`mysql_install_db': mysql-install-db. looks for support files such
as the error message file and the file for populating the help
tables. This option was added in MySQL 5.0.32.

* `--user=USER_NAME'

The login user name to use for running *Note `mysqld': mysqld.
Files and directories created by *Note `mysqld': mysqld. will be
owned by this user. You must be `root' to use this option. By
default, *Note `mysqld': mysqld. runs using your current login
name and files and directories that it creates will be owned by
you.

* `--verbose'

Verbose mode. Print more information about what the program does.

* `--windows'

For internal use. This option is used for creating Windows
distributions.

File: manual.info, Node: mysql-secure-installation, Next: mysql-tzinfo-to-sql, Prev: mysql-install-db, Up: programs-installation

5.4.7 `mysql_secure_installation' -- Improve MySQL Installation Security
------------------------------------------------------------------------

This program enables you to improve the security of your MySQL
installation in the following ways:

* You can set a password for `root' accounts.

* You can remove `root' accounts that are accessible from outside
the local host.

* You can remove anonymous-user accounts.

* You can remove the `test' database (which by default can be
accessed by all users, even anonymous users), and privileges that
permit anyone to access databases with names that start with
`test_'.

*Note `mysql_secure_installation': mysql-secure-installation. helps you
implement security recommendations similar to those described at *Note
default-privileges::.

Invoke *Note `mysql_secure_installation': mysql-secure-installation.
without arguments:

shell> mysql_secure_installation

The script will prompt you to determine which actions to perform.

*Note `mysql_secure_installation': mysql-secure-installation. is not
available on Windows.

File: manual.info, Node: mysql-tzinfo-to-sql, Next: mysql-upgrade, Prev: mysql-secure-installation, Up: programs-installation

5.4.8 `mysql_tzinfo_to_sql' -- Load the Time Zone Tables
--------------------------------------------------------

The *Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql. program loads the
time zone tables in the `mysql' database. It is used on systems that
have a _zoneinfo_ database (the set of files describing time zones).
Examples of such systems are Linux, FreeBSD, Solaris, and Mac OS X. One
likely location for these files is the `/usr/share/zoneinfo' directory
(`/usr/share/lib/zoneinfo' on Solaris). If your system does not have a
zoneinfo database, you can use the downloadable package described in
*Note time-zone-support::.

*Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql. can be invoked several
ways:

shell> mysql_tzinfo_to_sql TZ_DIR
shell> mysql_tzinfo_to_sql TZ_FILE TZ_NAME
shell> mysql_tzinfo_to_sql --leap TZ_FILE

For the first invocation syntax, pass the zoneinfo directory path name
to *Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql. and send the
output into the *Note `mysql': mysql. program. For example:

shell> mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql

*Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql. reads your system's
time zone files and generates SQL statements from them. *Note `mysql':
mysql. processes those statements to load the time zone tables.

The second syntax causes *Note `mysql_tzinfo_to_sql':
mysql-tzinfo-to-sql. to load a single time zone file TZ_FILE that
corresponds to a time zone name TZ_NAME:

shell> mysql_tzinfo_to_sql TZ_FILE TZ_NAME | mysql -u root mysql

If your time zone needs to account for leap seconds, invoke *Note
`mysql_tzinfo_to_sql': mysql-tzinfo-to-sql. using the third syntax,
which initializes the leap second information. TZ_FILE is the name of
your time zone file:

shell> mysql_tzinfo_to_sql --leap TZ_FILE | mysql -u root mysql

After running *Note `mysql_tzinfo_to_sql': mysql-tzinfo-to-sql, it is
best to restart the server so that it does not continue to use any
previously cached time zone data.

File: manual.info, Node: mysql-upgrade, Prev: mysql-tzinfo-to-sql, Up: programs-installation

5.4.9 `mysql_upgrade' -- Check Tables for MySQL Upgrade
-------------------------------------------------------

*Note `mysql_upgrade': mysql-upgrade. examines all tables in all
databases for incompatibilities with the current version of MySQL
Server. *Note `mysql_upgrade': mysql-upgrade. also upgrades the system
tables so that you can take advantage of new privileges or capabilities
that might have been added.

*Note `mysql_upgrade': mysql-upgrade. should be executed each time you
upgrade MySQL. It supersedes the older *Note
`mysql_fix_privilege_tables': mysql-fix-privilege-tables. script, which
should no longer be used.

If *Note `mysql_upgrade': mysql-upgrade. finds that a table has a
possible incompatibility, it performs a table check and, if problems
are found, attempts a table repair. If the table cannot be repaired,
see *Note rebuilding-tables:: for manual table repair strategies.

*Caution*:

You should always back up your current MySQL installation _before_
performing an upgrade. See *Note backup-methods::.

Some upgrade incompatibilities may require special handling before you
upgrade your MySQL installation and run *Note `mysql_upgrade':
mysql-upgrade. See *Note upgrading::, for instructions on determining
whether any such incompatibilities apply to your installation and how
to handle them.

To use *Note `mysql_upgrade': mysql-upgrade, make sure that the server
is running, and then invoke it like this:

shell> mysql_upgrade [OPTIONS]

After running *Note `mysql_upgrade': mysql-upgrade, stop the server and
restart it so that any changes made to the system tables take effect.

*Note `mysql_upgrade': mysql-upgrade. executes the following commands
to check and repair tables and to upgrade the system tables:

mysqlcheck --all-databases --check-upgrade --auto-repair
mysql < FIX_PRIV_TABLES

Notes about the preceding commands:

* Because *Note `mysql_upgrade': mysql-upgrade. invokes *Note
`mysqlcheck': mysqlcheck. with the `--all-databases' option, it
processes all tables in all databases, which might take a long
time to complete. Each table is locked and therefore unavailable
to other sessions while it is being processed. Check and repair
operations can be time-consuming, particularly for large tables.

* For details about what checks the `--check-upgrade' option
entails, see the description of the `FOR UPGRADE' option of the
*Note `CHECK TABLE': check-table. statement (see *Note
check-table::).

* FIX_PRIV_TABLES represents a script generated internally by *Note
`mysql_upgrade': mysql-upgrade. that contains SQL statements to
upgrade the tables in the `mysql' database.

All checked and repaired tables are marked with the current MySQL
version number. This ensures that next time you run *Note
`mysql_upgrade': mysql-upgrade. with the same version of the server, it
can tell whether there is any need to check or repair the table again.

*Note `mysql_upgrade': mysql-upgrade. also saves the MySQL version
number in a file named `mysql_upgrade_info' in the data directory. This
is used to quickly check whether all tables have been checked for this
release so that table-checking can be skipped. To ignore this file and
perform the check regardless, use the `--force' option.

If you install MySQL from RPM packages on Linux, you must install the
server and client RPMs. *Note `mysql_upgrade': mysql-upgrade. is
included in the server RPM but requires the client RPM because the
latter includes *Note `mysqlcheck': mysqlcheck. (See *Note
linux-installation-rpm::.)

In MySQL 5.0.19, `mysql_upgrade ' was added as a shell script and
worked only for Unix systems. As of MySQL 5.0.25, *Note
`mysql_upgrade': mysql-upgrade. is an executable binary and is
available on all systems.

*Note `mysql_upgrade': mysql-upgrade. does not upgrade the contents of
the help tables. For upgrade instructions, see *Note
server-side-help-support::.

*Note `mysql_upgrade': mysql-upgrade. supports the following options,
which can be specified on the command line or in the `[mysql_upgrade]'
and `[client]' option file groups. Other options are passed to *Note
`mysqlcheck': mysqlcheck. For example, it might be necessary to specify
the `--password[=PASSWORD]' option. *Note `mysql_upgrade':
mysql-upgrade. also supports the options for processing option files
described at *Note option-file-options::.

* `--help'

Display a short help message and exit.

* `--basedir=PATH'

The path to the MySQL installation directory. This option is
accepted for backward compatibility but ignored.

* `--datadir=PATH'

The path to the data directory. This option is accepted for
backward compatibility but ignored.

* `--force'

Ignore the `mysql_upgrade_info' file and force execution of *Note
`mysqlcheck': mysqlcheck. even if *Note `mysql_upgrade':
mysql-upgrade. has already been executed for the current version
of MySQL.

* `--tmpdir=PATH', `-t PATH'

The path name of the directory to use for creating temporary
files. This option was added in MySQL 5.0.62.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server. The
default user name is `root'.

* `--verbose'

Verbose mode. Print more information about what the program does.

File: manual.info, Node: programs-client, Next: programs-admin-utils, Prev: programs-installation, Up: programs

5.5 MySQL Client Programs
=========================

* Menu:

* mysql:: `mysql' --- The MySQL Command-Line Tool
* mysqladmin:: `mysqladmin' --- Client for Administering a MySQL Server
* mysqlcheck:: `mysqlcheck' --- A Table Maintenance Program
* mysqldump:: `mysqldump' --- A Database Backup Program
* mysqlimport:: `mysqlimport' --- A Data Import Program
* mysqlshow:: `mysqlshow' --- Display Database, Table, and Column Information

This section describes client programs that connect to the MySQL server.

File: manual.info, Node: mysql, Next: mysqladmin, Prev: programs-client, Up: programs-client

5.5.1 `mysql' -- The MySQL Command-Line Tool
--------------------------------------------

* Menu:

* mysql-command-options:: `mysql' Options
* mysql-commands:: `mysql' Commands
* mysql-history-file:: `mysql' History File
* mysql-server-side-help:: `mysql' Server-Side Help
* batch-commands:: Executing SQL Statements from a Text File
* mysql-tips:: `mysql' Tips

*Note `mysql': mysql. is a simple SQL shell (with GNU `readline'
capabilities). It supports interactive and noninteractive use. When
used interactively, query results are presented in an ASCII-table
format. When used noninteractively (for example, as a filter), the
result is presented in tab-separated format. The output format can be
changed using command options.

If you have problems due to insufficient memory for large result sets,
use the `--quick' option. This forces *Note `mysql': mysql. to retrieve
results from the server a row at a time rather than retrieving the
entire result set and buffering it in memory before displaying it. This
is done by returning the result set using the *Note
`mysql_use_result()': mysql-use-result. C API function in the
client/server library rather than *Note `mysql_store_result()':
mysql-store-result.

Using *Note `mysql': mysql. is very easy. Invoke it from the prompt of
your command interpreter as follows:

shell> mysql DB_NAME

Or:

shell> mysql --user=USER_NAME --password=YOUR_PASSWORD DB_NAME

Then type an SQL statement, end it with ``;'', `\g', or `\G' and press
Enter.

As of MySQL 5.0.25, typing Control-C causes *Note `mysql': mysql. to
attempt to kill the current statement. If this cannot be done, or
Control-C is typed again before the statement is killed, *Note `mysql':
mysql. exits. Previously, Control-C caused *Note `mysql': mysql. to
exit in all cases.

You can execute SQL statements in a script file (batch file) like this:

shell> mysql DB_NAME < SCRIPT.SQL > OUTPUT.TAB

On Unix, the *Note `mysql': mysql. client writes a record of executed
statements to a history file. See *Note mysql-history-file::.

File: manual.info, Node: mysql-command-options, Next: mysql-commands, Prev: mysql, Up: mysql

5.5.1.1 `mysql' Options
.......................

*Note `mysql': mysql. supports the following options, which can be
specified on the command line or in the `[mysql]' and `[client]' option
file groups. *Note `mysql': mysql. also supports the options for
processing option files described at *Note option-file-options::.

*`mysql' Options*

Format Option File Description IntroductionDeprecatedRemoved
-auto-rehashauto-rehash Enable automatic rehashing
-batch batch Don't use history file
-character-sets-dir=pathcharacter-sets-dirSet the default character set
-column-namescolumn-namesWrite column names in results
-comments comments Whether to retain or strip 5.0.52
comments in statements sent
to the server
-compress compress Compress all information
sent between the client and
the server
-connect_timeout=valueconnect_timeoutThe number of seconds before
connection timeout
-database=dbnamedatabase The database to use
-debug[=debug_options]debug Write a debugging log
-debug-info debug-info Print debugging information,
memory and CPU statistics
when the program exits
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-delimiter=strdelimiter Set the statement delimiter
-execute=statementexecute Execute the statement and
quit
-force force Continue even if an SQL
error occurs
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-html html Produce HTML output
-ignore-spacesignore-spacesIgnore spaces after function
names
-line-numbersline-numbersWrite line numbers for errors
-local-infile[={0|1}]local-infileEnable or disable for LOCAL
capability for LOAD DATA
INFILE
-max_allowed_packet=valuemax_allowed_packetThe maximum packet length to
send to or receive from the
server
-max_join_size=valuemax_join_sizeThe automatic limit for rows
in a join when using
-safe-updates
-named-commandsnamed-commandsEnable named mysql commands
-net_buffer_length=valuenet_buffer_lengthThe buffer size for TCP/IP
and socket communication
-no-auto-rehash Disable automatic rehashing
-no-beep no-beep Do not beep when errors occur
-no-named-commandsno-named-commandsDisable named mysql commands
-no-pager no-pager Deprecated form of
-skip-pager
-no-tee no-tee Do not copy output to a file
-one-databaseone-databaseIgnore statements except
those for the default
database named on the
command line
-pager[=command]pager Use the given command for
paging query output
-password[=password]password The password to use when
connecting to the server
-port=port_numport The TCP/IP port number to
use for the connection
-prompt=format_strprompt Set the prompt to the
specified format
-protocol=typeprotocol The connection protocol to
use
-quick quick Do not cache each query
result
-raw raw Write column values without
escape conversion
-reconnect reconnect If the connection to the
server is lost,
automatically try to
reconnect
-safe-updatessafe-updatesAllow only UPDATE and DELETE
statements that specify key
values
-secure-authsecure-auth Do not send passwords to the
server in old (pre-4.1.1)
format
-select_limit=valueselect_limitThe automatic limit for
SELECT statements when using
-safe-updates
-show-warningsshow-warningsShow warnings after each 5.0.6
statement if there are any
-sigint-ignoresigint-ignoreIgnore SIGINT signals
(typically the result of
typing Control-C)
-silent silent Silent mode
-skip-auto-rehashskip-auto-rehashDisable automatic rehashing
-skip-column-namesskip-column-namesDo not write column names in
results
-skip-line-numbersskip-line-numbersSkip line numbers for errors
-skip-named-commandsskip-named-commandsDisable named mysql commands
-skip-pager skip-pager Disable paging
-skip-reconnectskip-reconnectDisable reconnecting
-socket=pathsocket For connections to localhost
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-table table Display output in tabular
format
-tee=file_nametee Append a copy of output to
the given file
-unbuffered unbuffered Flush the buffer after each
query
-user=user_nameuser The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit
-vertical vertical Print query output rows
vertically (one line per
column value)
-wait wait If the connection cannot be
established, wait and retry
instead of aborting
-xml xml Produce XML output

* `--help', `-?'

Display a help message and exit.

* `--auto-rehash'

Enable automatic rehashing. This option is on by default, which
enables database, table, and column name completion. Use
`--disable-auto-rehash' to disable rehashing. That causes *Note
`mysql': mysql. to start faster, but you must issue the `rehash'
command if you want to use name completion.

To complete a name, enter the first part and press Tab. If the
name is unambiguous, *Note `mysql': mysql. completes it.
Otherwise, you can press Tab again to see the possible names that
begin with what you have typed so far. Completion does not occur
if there is no default database.

* `--batch', `-B'

Print results using tab as the column separator, with each row on
a new line. With this option, *Note `mysql': mysql. does not use
the history file.

Batch mode results in nontabular output format and escaping of
special characters. Escaping may be disabled by using raw mode;
see the description for the `--raw' option.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--column-names'

Write column names in results.

* `--comments', `-c'

Whether to preserve comments in statements sent to the server. The
default is -skip-comments (discard comments), enable with
-comments (preserve comments). This option was added in MySQL
5.0.52.

* `--compress', `-C'

Compress all information sent between the client and the server if
both support compression.

* `--database=DB_NAME', `-D DB_NAME'

The database to use. This is useful primarily in an option file.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is `'d:t:o,/tmp/mysql.trace''.

* `--debug-info', `-T'

Print some debugging information when the program exits.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set for the client and
connection.

A common issue that can occur when the operating system uses
`utf8' or another multi-byte character set is that output from the
*Note `mysql': mysql. client is formatted incorrectly, due to the
fact that the MySQL client uses the `latin1' character set by
default. You can usually fix such issues by using this option to
force the client to use the system character set instead.

See *Note charset-configuration::, for more information.

* `--delimiter=STR'

Set the statement delimiter. The default is the semicolon
character (``;'').

* `--disable-named-commands'

Disable named commands. Use the `\*' form only, or use named
commands only at the beginning of a line ending with a semicolon
(``;''). *Note `mysql': mysql. starts with this option _enabled_
by default. However, even with this option, long-format commands
still work from the first line. See *Note mysql-commands::.

* `--execute=STATEMENT', `-e STATEMENT'

Execute the statement and quit. The default output format is like
that produced with `--batch'. See *Note command-line-options::,
for some examples. With this option, *Note `mysql': mysql. does
not use the history file.

* `--force', `-f'

Continue even if an SQL error occurs.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--html', `-H'

Produce HTML output.

* `--ignore-spaces', `-i'

Ignore spaces after function names. The effect of this is
described in the discussion for the `IGNORE_SPACE' SQL mode (see
*Note server-sql-mode::).

* `--line-numbers'

Write line numbers for errors. Disable this with
`--skip-line-numbers'.

* `--local-infile[={0|1}]'

Enable or disable `LOCAL' capability for *Note `LOAD DATA INFILE':
load-data. With no value, the option enables `LOCAL'. The option
may be given as `--local-infile=0' or `--local-infile=1' to
explicitly disable or enable `LOCAL'. Enabling `LOCAL' has no
effect if the server does not also support it.

* `--named-commands', `-G'

Enable named *Note `mysql': mysql. commands. Long-format commands
are permitted, not just short-format commands. For example, `quit'
and `\q' both are recognized. Use `--skip-named-commands' to
disable named commands. See *Note mysql-commands::.

* `--no-auto-rehash', `-A'

This has the same effect as `-skip-auto-rehash'. See the
description for `--auto-rehash'.

* `--no-beep', `-b'

Do not beep when errors occur.

* `--no-named-commands', `-g'

Deprecated, use `--disable-named-commands' instead.
`--no-named-commands' is removed in MySQL 5.5.

* `--no-pager'

Deprecated form of `--skip-pager'. See the `--pager' option.
`--no-pager' is removed in MySQL 5.5.

* `--no-tee'

Deprecated form of `--skip-tee'. See the `--tee' option.
`--no-tee' is removed in MySQL 5.5.

* `--one-database', `-o'

Ignore statements except those that occur while the default
database is the one named on the command line. This option is
rudimentary and should be used with care. Statement filtering is
based only on *Note `USE': use. statements.

Initially, *Note `mysql': mysql. executes statements in the input
because specifying a database DB_NAME on the command line is
equivalent to inserting *Note `USE DB_NAME': use. at the beginning
of the input. Then, for each *Note `USE': use. statement
encountered, *Note `mysql': mysql. accepts or rejects following
statements depending on whether the database named is the one on
the command line. The content of the statements is immaterial.

Suppose that *Note `mysql': mysql. is invoked to process this set
of statements:

DELETE FROM db2.t2;
USE db2;
DROP TABLE db1.t1;
CREATE TABLE db1.t1 (i INT);
USE db1;
INSERT INTO t1 (i) VALUES(1);
CREATE TABLE db2.t1 (j INT);

If the command line is *Note `mysql --force --one-database db1':
mysql, *Note `mysql': mysql. handles the input as follows:

* The *Note `DELETE': delete. statement is executed because the
default database is `db1', even though the statement names a
table in a different database.

* The *Note `DROP TABLE': drop-table. and *Note `CREATE TABLE':
create-table. statements are not executed because the default
database is not `db1', even though the statements name a
table in `db1'.

* The *Note `INSERT': insert. and *Note `CREATE TABLE':
create-table. statements are executed because the default
database is `db1', even though the *Note `CREATE TABLE':
create-table. statement names a table in a different database.

* `--pager[=COMMAND]'

Use the given command for paging query output. If the command is
omitted, the default pager is the value of your `PAGER'
environment variable. Valid pagers are `less', `more', `cat [>
filename]', and so forth. This option works only on Unix and only
in interactive mode. To disable paging, use `--skip-pager'. *Note
mysql-commands::, discusses output paging further.

* `--password[=PASSWORD]', `-p[PASSWORD]'

The password to use when connecting to the server. If you use the
short option form (`-p'), you _cannot_ have a space between the
option and the password. If you omit the PASSWORD value following
the `--password' or `-p' option on the command line, *Note
`mysql': mysql. prompts for one.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--prompt=FORMAT_STR'

Set the prompt to the specified format. The default is `mysql>'.
The special sequences that the prompt can contain are described in
*Note mysql-commands::.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

The connection protocol to use for connecting to the server. It
is useful when the other connection parameters normally would
cause a protocol to be used other than the one you want. For
details on the permissible values, see *Note connecting::.

* `--quick', `-q'

Do not cache each query result, print each row as it is received.
This may slow down the server if the output is suspended. With
this option, *Note `mysql': mysql. does not use the history file.

* `--raw', `-r'

For tabular output, the `boxing' around columns enables one column
value to be distinguished from another. For nontabular output
(such as is produced in batch mode or when the `--batch' or
`--silent' option is given), special characters are escaped in the
output so they can be identified easily. Newline, tab, `NUL', and
backslash are written as `\n', `\t', `\0', and `\\'. The `--raw'
option disables this character escaping.

The following example demonstrates tabular versus nontabular
output and the use of raw mode to disable escaping:

% mysql
mysql> SELECT CHAR(92);
+----------+
| CHAR(92) |
+----------+
| \ |
+----------+

% mysql -s
mysql> SELECT CHAR(92);
CHAR(92)
\\

% mysql -s -r
mysql> SELECT CHAR(92);
CHAR(92)
\

* `--reconnect'

If the connection to the server is lost, automatically try to
reconnect. A single reconnect attempt is made each time the
connection is lost. To suppress reconnection behavior, use
`--skip-reconnect'.

* `--safe-updates', `--i-am-a-dummy', `-U'

Permit only those *Note `UPDATE': update. and *Note `DELETE':
delete. statements that specify which rows to modify by using key
values. If you have set this option in an option file, you can
override it by using `--safe-updates' on the command line. See
*Note mysql-tips::, for more information about this option.

* `--secure-auth'

Do not send passwords to the server in old (pre-4.1.1) format.
This prevents connections except for servers that use the newer
password format.

* `--show-warnings'

Cause warnings to be shown after each statement if there are any.
This option applies to interactive and batch mode. This option was
added in MySQL 5.0.6.

* `--sigint-ignore'

Ignore `SIGINT' signals (typically the result of typing Control-C).

* `--silent', `-s'

Silent mode. Produce less output. This option can be given
multiple times to produce less and less output.

This option results in nontabular output format and escaping of
special characters. Escaping may be disabled by using raw mode;
see the description for the `--raw' option.

* `--skip-column-names', `-N'

Do not write column names in results.

* `--skip-line-numbers', `-L'

Do not write line numbers for errors. Useful when you want to
compare result files that include error messages.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--table', `-t'

Display output in table format. This is the default for
interactive use, but can be used to produce table output in batch
mode.

* `--tee=FILE_NAME'

Append a copy of output to the given file. This option works only
in interactive mode. *Note mysql-commands::, discusses tee files
further.

* `--unbuffered', `-n'

Flush the buffer after each query.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Produce more output about what the program does.
This option can be given multiple times to produce more and more
output. (For example, `-v -v -v' produces table output format even
in batch mode.)

* `--version', `-V'

Display version information and exit.

* `--vertical', `-E'

Print query output rows vertically (one line per column value).
Without this option, you can specify vertical output for
individual statements by terminating them with `\G'.

* `--wait', `-w'

If the connection cannot be established, wait and retry instead of
aborting.

* `--xml', `-X'

Produce XML output.

*Note*:

Prior to MySQL 5.0.26, there was no differentiation in the output
when using this option between columns containing the `NULL' value
and columns containing the string literal `'NULL''; both were
represented as

Beginning with MySQL 5.0.26, the output when `--xml' is used with
*Note `mysql': mysql. matches that of *Note `mysqldump `--xml'':
mysqldump. See *Note mysqldump:: for details.

Beginning with MySQL 5.0.40, the XML output also uses an XML
namespace, as shown here:

shell> mysql --xml -uroot -e "SHOW VARIABLES LIKE 'version%'"
<?xml version="1.0"?>

<resultset statement="SHOW VARIABLES LIKE 'version%'" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<row>
<field name="Variable_name">version</field>
<field name="Value">5.0.40-debug</field>
</row>

<row>
<field name="Variable_name">version_comment</field>
<field name="Value">Source distribution</field>
</row>

<row>
<field name="Variable_name">version_compile_machine</field>
<field name="Value">i686</field>
</row>

<row>
<field name="Variable_name">version_compile_os</field>
<field name="Value">suse-linux-gnu</field>
</row>
</resultset>

(See Bug#25946 (http://bugs.mysql.com/bug.php?id=25946).)

You can also set the following variables by using `--VAR_NAME=VALUE'.
The `--set-variable' format is deprecated.

* `connect_timeout'

The number of seconds before connection timeout. (Default value is
`0'.)

* `max_allowed_packet'

The maximum packet length to send to or receive from the server.
(Default value is 16MB.)

* `max_join_size'

The automatic limit for rows in a join when using
`--safe-updates'. (Default value is 1,000,000.)

* `net_buffer_length'

The buffer size for TCP/IP and socket communication. (Default
value is 16KB.)

* `select_limit'

The automatic limit for *Note `SELECT': select. statements when
using `--safe-updates'. (Default value is 1,000.)

It is also possible to set variables by using `--VAR_NAME=VALUE'. The
`--set-variable' format is deprecated.

File: manual.info, Node: mysql-commands, Next: mysql-history-file, Prev: mysql-command-options, Up: mysql

5.5.1.2 `mysql' Commands
........................

*Note `mysql': mysql. sends each SQL statement that you issue to the
server to be executed. There is also a set of commands that *Note
`mysql': mysql. itself interprets. For a list of these commands, type
`help' or `\h' at the `mysql>' prompt:

mysql> help

List of all MySQL commands:
Note that all text commands must be first on line and end with ';'
? (\?) Synonym for `help'.
clear (\c) Clear command.
connect (\r) Reconnect to the server. Optional arguments are db and host.
delimiter (\d) Set statement delimiter.
edit (\e) Edit command with $EDITOR.
ego (\G) Send command to mysql server, display result vertically.
exit (\q) Exit mysql. Same as quit.
go (\g) Send command to mysql server.
help (\h) Display this help.
nopager (\n) Disable pager, print to stdout.
notee (\t) Don't write into outfile.
pager (\P) Set PAGER [to_pager]. Print the query results via PAGER.
print (\p) Print current command.
prompt (\R) Change your mysql prompt.
quit (\q) Quit mysql.
rehash (\#) Rebuild completion hash.
source (\.) Execute an SQL script file. Takes a file name as an argument.
status (\s) Get status information from the server.
system (\!) Execute a system shell command.
tee (\T) Set outfile [to_outfile]. Append everything into given
outfile.
use (\u) Use another database. Takes database name as argument.
charset (\C) Switch to another charset. Might be needed for processing
binlog with multi-byte charsets.
warnings (\W) Show warnings after every statement.
nowarning (\w) Don't show warnings after every statement.

For server side help, type 'help contents'

Each command has both a long and short form. The long form is not case
sensitive; the short form is. The long form can be followed by an
optional semicolon terminator, but the short form should not.

The use of short-form commands within multi-line `/* ... */' comments
is not supported.

* *Note `help [ARG]': help, `\h [ARG]', `\? [ARG]', `? [ARG]'

Display a help message listing the available *Note `mysql': mysql.
commands.

If you provide an argument to the `help' command, *Note `mysql':
mysql. uses it as a search string to access server-side help from
the contents of the MySQL Reference Manual. For more information,
see *Note mysql-server-side-help::.

* *Note `charset CHARSET_NAME': charset, `\C CHARSET_NAME'

Change the default character set and issue a `SET NAMES'
statement. This enables the character set to remain synchronized
on the client and server if *Note `mysql': mysql. is run with
auto-reconnect enabled (which is not recommended), because the
specified character set is used for reconnects. This command was
added in MySQL 5.0.19.

* `clear', `\c'

Clear the current input. Use this if you change your mind about
executing the statement that you are entering.

* `connect [DB_NAME HOST_NAME]]', `\r [DB_NAME HOST_NAME]]'

Reconnect to the server. The optional database name and host name
arguments may be given to specify the default database or the host
where the server is running. If omitted, the current values are
used.

* `delimiter STR', `\d STR'

Change the string that *Note `mysql': mysql. interprets as the
separator between SQL statements. The default is the semicolon
character (``;'').

The delimiter can be specified as an unquoted or quoted argument.
Quoting can be done with either single quote (`'') or douple quote
(`"') characters. To include a quote within a quoted string,
either quote the string with the other quote character or escape
the quote with a backslash (``\'') character. Backslash should be
avoided outside of quoted strings because it is the escape
character for MySQL. For an unquoted argument, the delmiter is
read up to the first space or end of line. For a quoted argument,
the delimiter is read up to the matching quote on the line.

When the delimiter recognized by *Note `mysql': mysql. is set to
something other than the default of ``;'', instances of that
character are sent to the server without interpretation. However,
the server itself still interprets ``;'' as a statement delimiter
and processes statements accordingly. This behavior on the server
side comes into play for multiple-statement execution (see *Note
c-api-multiple-queries::), and for parsing the body of stored
procedures and functions and triggers (see *Note
stored-programs-defining::).

* `edit', `\e'

Edit the current input statement. *Note `mysql': mysql. checks
the values of the `EDITOR' and `VISUAL' environment variables to
determine which editor to use. The default editor is `vi' if
neither variable is set.

The `edit' command works only in Unix.

* `ego', `\G'

Send the current statement to the server to be executed and
display the result using vertical format.

Be careful about defining a delimiter that might occur within
other words. For example, if you define the delimiter as `X', you
will be unable to use the word `INDEX' in statements.

* `exit', `\q'

Exit *Note `mysql': mysql.

* `go', `\g'

Send the current statement to the server to be executed.

* `nopager', `\n'

Disable output paging. See the description for `pager'.

The `nopager' command works only in Unix.

* `notee', `\t'

Disable output copying to the tee file. See the description for
`tee'.

* `nowarning', `\w'

Enable display of warnings after each statement. This command was
added in MySQL 5.0.6.

* `pager [COMMAND]', `\P [COMMAND]'

Enable output paging. By using the `--pager' option when you invoke
*Note `mysql': mysql, it is possible to browse or search query
results in interactive mode with Unix programs such as `less',
`more', or any other similar program. If you specify no value for
the option, *Note `mysql': mysql. checks the value of the `PAGER'
environment variable and sets the pager to that. Pager
functionality works only in interactive mode.

Output paging can be enabled interactively with the `pager'
command and disabled with `nopager'. The command takes an optional
argument; if given, the paging program is set to that. With no
argument, the pager is set to the pager that was set on the
command line, or `stdout' if no pager was specified.

Output paging works only in Unix because it uses the `popen()'
function, which does not exist on Windows. For Windows, the `tee'
option can be used instead to save query output, although it is
not as convenient as `pager' for browsing output in some
situations.

* `print', `\p'

Print the current input statement without executing it.

* `prompt [STR]', `\R [STR]'

Reconfigure the *Note `mysql': mysql. prompt to the given string.
The special character sequences that can be used in the prompt are
described later in this section.

If you specify the `prompt' command with no argument, *Note
`mysql': mysql. resets the prompt to the default of `mysql>'.

* `quit', `\q'

Exit *Note `mysql': mysql.

* `rehash', `\#'

Rebuild the completion hash that enables database, table, and
column name completion while you are entering statements. (See the
description for the `--auto-rehash' option.)

* `source FILE_NAME', `\. FILE_NAME'

Read the named file and executes the statements contained therein.
On Windows, you can specify path name separators as `/' or `\\'.

* `status', `\s'

Provide status information about the connection and the server you
are using. If you are running in `--safe-updates' mode, `status'
also prints the values for the *Note `mysql': mysql. variables
that affect your queries.

* `system COMMAND', `\! COMMAND'

Execute the given command using your default command interpreter.

The `system' command works only in Unix.

* `tee [FILE_NAME]', `\T [FILE_NAME]'

By using the `--tee' option when you invoke *Note `mysql': mysql,
you can log statements and their output. All the data displayed on
the screen is appended into a given file. This can be very useful
for debugging purposes also. *Note `mysql': mysql. flushes results
to the file after each statement, just before it prints its next
prompt. Tee functionality works only in interactive mode.

You can enable this feature interactively with the `tee' command.
Without a parameter, the previous file is used. The `tee' file can
be disabled with the `notee' command. Executing `tee' again
re-enables logging.

* *Note `use DB_NAME': use, `\u DB_NAME'

Use DB_NAME as the default database.

* `warnings', `\W'

Enable display of warnings after each statement (if there are
any). This command was added in MySQL 5.0.6.

Here are a few tips about the `pager' command:

* You can use it to write to a file and the results go only to the
file:

mysql> pager cat > /tmp/log.txt

You can also pass any options for the program that you want to use
as your pager:

mysql> pager less -n -i -S

* In the preceding example, note the `-S' option. You may find it
very useful for browsing wide query results. Sometimes a very wide
result set is difficult to read on the screen. The `-S' option to
`less' can make the result set much more readable because you can
scroll it horizontally using the left-arrow and right-arrow keys.
You can also use `-S' interactively within `less' to switch the
horizontal-browse mode on and off. For more information, read the
`less' manual page:

shell> man less

* The `-F' and `-X' options may be used with `less' to cause it to
exit if output fits on one screen, which is convenient when no
scrolling is necessary:

mysql> pager less -n -i -S -F -X

* You can specify very complex pager commands for handling query
output:

mysql> pager cat | tee /dr1/tmp/res.txt \
| tee /dr2/tmp/res2.txt | less -n -i -S

In this example, the command would send query results to two files
in two different directories on two different file systems mounted
on `/dr1' and `/dr2', yet still display the results onscreen using
`less'.

You can also combine the `tee' and `pager' functions. Have a `tee' file
enabled and `pager' set to `less', and you are able to browse the
results using the `less' program and still have everything appended
into a file the same time. The difference between the Unix `tee' used
with the `pager' command and the *Note `mysql': mysql. built-in `tee'
command is that the built-in `tee' works even if you do not have the
Unix `tee' available. The built-in `tee' also logs everything that is
printed on the screen, whereas the Unix `tee' used with `pager' does
not log quite that much. Additionally, `tee' file logging can be turned
on and off interactively from within *Note `mysql': mysql. This is
useful when you want to log some queries to a file, but not others.

The `prompt' command reconfigures the default `mysql>' prompt. The
string for defining the prompt can contain the following special
sequences.

Option Description
`\c' A counter that increments for each statement you issue
`\D' The full current date
`\d' The default database
`\h' The server host
`\l' The current delimiter (new in 5.0.25)
`\m' Minutes of the current time
`\n' A newline character
`\O' The current month in three-letter format (Jan, Feb,
...)
`\o' The current month in numeric format
`\P' am/pm
`\p' The current TCP/IP port or socket file
`\R' The current time, in 24-hour military time (0-23)
`\r' The current time, standard 12-hour time (1-12)
`\S' Semicolon
`\s' Seconds of the current time
`\t' A tab character
`\U' Your full `USER_NAME@HOST_NAME' account name
`\u' Your user name
`\v' The server version
`\w' The current day of the week in three-letter format
(Mon, Tue, ...)
`\Y' The current year, four digits
`\y' The current year, two digits
`\_' A space
`\ ' A space (a space follows the backslash)
`\'' Single quote
`\"' Double quote
`\\' A literal ``\'' backslash character
`\X' X, for any `X' not listed above

You can set the prompt in several ways:

* _Use an environment variable._ You can set the `MYSQL_PS1'
environment variable to a prompt string. For example:

shell> export MYSQL_PS1="(\u@\h) [\d]> "

* _Use a command-line option._ You can set the `--prompt' option on
the command line to *Note `mysql': mysql. For example:

shell> mysql --prompt="(\u@\h) [\d]> "
(user@host) [database]>

* _Use an option file._ You can set the `prompt' option in the
`[mysql]' group of any MySQL option file, such as `/etc/my.cnf' or
the `.my.cnf' file in your home directory. For example:

[mysql]
prompt=(\\u@\\h) [\\d]>\\_

In this example, note that the backslashes are doubled. If you set
the prompt using the `prompt' option in an option file, it is
advisable to double the backslashes when using the special prompt
options. There is some overlap in the set of permissible prompt
options and the set of special escape sequences that are
recognized in option files. (The rules for escape sequences in
option files are listed in *Note option-files::.) The overlap may
cause you problems if you use single backslashes. For example,
`\s' is interpreted as a space rather than as the current seconds
value. The following example shows how to define a prompt within
an option file to include the current time in `HH:MM:SS>' format:

[mysql]
prompt="\\r:\\m:\\s> "

* _Set the prompt interactively._ You can change your prompt
interactively by using the `prompt' (or `\R') command. For example:

mysql> prompt (\u@\h) [\d]>\_
PROMPT set to '(\u@\h) [\d]>\_'
(USER@HOST) [DATABASE]>
(USER@HOST) [DATABASE]> prompt
Returning to default PROMPT of mysql>
mysql>

File: manual.info, Node: mysql-history-file, Next: mysql-server-side-help, Prev: mysql-commands, Up: mysql

5.5.1.3 `mysql' History File
............................

On Unix, the *Note `mysql': mysql. client writes a record of executed
statements to a history file. By default, this file is named
`.mysql_history' and is created in your home directory. To specify a
different file, set the value of the `MYSQL_HISTFILE' environment
variable.

The `.mysql_history' should be protected with a restrictive access mode
because sensitive information might be written to it, such as the text
of SQL statements that contain passwords. See *Note
password-security-user::.

It is possible to suppress logging of statements to the history file by
using the `--batch' or `--execute' option.

If you do not want to maintain a history file, first remove
`.mysql_history' if it exists, and then use either of the following
techniques:

* Set the `MYSQL_HISTFILE' variable to `/dev/null'. To cause this
setting to take effect each time you log in, put the setting in
one of your shell's startup files.

* Create `.mysql_history' as a symbolic link to `/dev/null':

shell> ln -s /dev/null $HOME/.mysql_history

You need do this only once.

File: manual.info, Node: mysql-server-side-help, Next: batch-commands, Prev: mysql-history-file, Up: mysql

5.5.1.4 `mysql' Server-Side Help
................................

mysql> help SEARCH_STRING

If you provide an argument to the `help' command, *Note `mysql': mysql.
uses it as a search string to access server-side help from the contents
of the MySQL Reference Manual. The proper operation of this command
requires that the help tables in the `mysql' database be initialized
with help topic information (see *Note server-side-help-support::).

If there is no match for the search string, the search fails:

mysql> help me

Nothing found
Please try to run 'help contents' for a list of all accessible topics

Use *Note `help contents': help. to see a list of the help categories:

mysql> help contents
You asked for help about help category: "Contents"
For more information, type 'help <item>', where <item> is one of the
following categories:
Account Management
Administration
Data Definition
Data Manipulation
Data Types
Functions
Functions and Modifiers for Use with GROUP BY
Geographic Features
Language Structure
Storage Engines
Stored Routines
Table Maintenance
Transactions
Triggers

If the search string matches multiple items, *Note `mysql': mysql.
shows a list of matching topics:

mysql> help logs
Many help items for your request exist.
To make a more specific request, please type 'help <item>',
where <item> is one of the following topics:
SHOW
SHOW BINARY LOGS
SHOW ENGINE
SHOW LOGS

Use a topic as the search string to see the help entry for that topic:

mysql> help show binary logs
Name: 'SHOW BINARY LOGS'
Description:
Syntax:
SHOW BINARY LOGS
SHOW MASTER LOGS

Lists the binary log files on the server. This statement is used as
part of the procedure described in [purge-binary-logs], that shows how
to determine which logs can be purged.

mysql> SHOW BINARY LOGS;
+---------------+-----------+
| Log_name | File_size |
+---------------+-----------+
| binlog.000015 | 724935 |
| binlog.000016 | 733481 |
+---------------+-----------+

File: manual.info, Node: batch-commands, Next: mysql-tips, Prev: mysql-server-side-help, Up: mysql

5.5.1.5 Executing SQL Statements from a Text File
.................................................

The *Note `mysql': mysql. client typically is used interactively, like
this:

shell> mysql DB_NAME

However, it is also possible to put your SQL statements in a file and
then tell *Note `mysql': mysql. to read its input from that file. To do
so, create a text file TEXT_FILE that contains the statements you wish
to execute. Then invoke *Note `mysql': mysql. as shown here:

shell> mysql DB_NAME < TEXT_FILE

If you place a `USE DB_NAME' statement as the first statement in the
file, it is unnecessary to specify the database name on the command
line:

shell> mysql < text_file

If you are already running *Note `mysql': mysql, you can execute an SQL
script file using the `source' command or `\.' command:

mysql> source FILE_NAME
mysql> \. FILE_NAME

Sometimes you may want your script to display progress information to
the user. For this you can insert statements like this:

SELECT '<info_to_display>' AS ' ';

The statement shown outputs `<info_to_display>'.

You can also invoke *Note `mysql': mysql. with the `--verbose' option,
which causes each statement to be displayed before the result that it
produces.

As of MySQL 5.0.54, *Note `mysql': mysql. ignores Unicode byte order
mark (BOM) characters at the beginning of input files. Previously, it
read them and sent them to the server, resulting in a syntax error.
Presence of a BOM does not cause *Note `mysql': mysql. to change its
default character set. To do that, invoke *Note `mysql': mysql. with an
option such as `--default-character-set=utf8'.

For more information about batch mode, see *Note batch-mode::.

File: manual.info, Node: mysql-tips, Prev: batch-commands, Up: mysql

5.5.1.6 `mysql' Tips
....................

* Menu:

* vertical-query-results:: Displaying Query Results Vertically
* safe-updates:: Using the `--safe-updates' Option
* mysql-reconnect:: Disabling `mysql' Auto-Reconnect

This section describes some techniques that can help you use *Note
`mysql': mysql. more effectively.

File: manual.info, Node: vertical-query-results, Next: safe-updates, Prev: mysql-tips, Up: mysql-tips

5.5.1.7 Displaying Query Results Vertically
...........................................

Some query results are much more readable when displayed vertically,
instead of in the usual horizontal table format. Queries can be
displayed vertically by terminating the query with \G instead of a
semicolon. For example, longer text values that include newlines often
are much easier to read with vertical output:

mysql> SELECT * FROM mails WHERE LENGTH(txt) < 300 LIMIT 300,1\G
*************************** 1. row ***************************
msg_nro: 3068
date: 2000-03-01 23:29:50
time_zone: +0200
mail_from: Monty
reply: monty@no.spam.com
mail_to: "Thimble Smith" <tim@no.spam.com>
sbj: UTF-8
txt: >>>>> "Thimble" == Thimble Smith writes:

Thimble> Hi. I think this is a good idea. Is anyone familiar
Thimble> with UTF-8 or Unicode? Otherwise, I'll put this on my
Thimble> TODO list and see what happens.

Yes, please do that.

Regards,
Monty
file: inbox-jani-1
hash: 190402944
1 row in set (0.09 sec)

File: manual.info, Node: safe-updates, Next: mysql-reconnect, Prev: vertical-query-results, Up: mysql-tips

5.5.1.8 Using the `--safe-updates' Option
.........................................

For beginners, a useful startup option is `--safe-updates' (or
`--i-am-a-dummy', which has the same effect). It is helpful for cases
when you might have issued a `DELETE FROM TBL_NAME' statement but
forgotten the `WHERE' clause. Normally, such a statement deletes all
rows from the table. With `--safe-updates', you can delete rows only by
specifying the key values that identify them. This helps prevent
accidents.

When you use the `--safe-updates' option, *Note `mysql': mysql. issues
the following statement when it connects to the MySQL server:

SET sql_safe_updates=1, sql_select_limit=1000, sql_max_join_size=1000000;

See *Note server-system-variables::.

The *Note `SET': set-option. statement has the following effects:

* You are not permitted to execute an *Note `UPDATE': update. or
*Note `DELETE': delete. statement unless you specify a key
constraint in the `WHERE' clause or provide a `LIMIT' clause (or
both). For example:

UPDATE TBL_NAME SET NOT_KEY_COLUMN=VAL WHERE KEY_COLUMN=VAL;

UPDATE TBL_NAME SET NOT_KEY_COLUMN=VAL LIMIT 1;

* The server limits all large *Note `SELECT': select. results to
1,000 rows unless the statement includes a `LIMIT' clause.

* The server aborts multiple-table *Note `SELECT': select.
statements that probably need to examine more than 1,000,000 row
combinations.

To specify limits different from 1,000 and 1,000,000, you can override
the defaults by using the `--select_limit' and `--max_join_size'
options:

shell> mysql --safe-updates --select_limit=500 --max_join_size=10000

File: manual.info, Node: mysql-reconnect, Prev: safe-updates, Up: mysql-tips

5.5.1.9 Disabling `mysql' Auto-Reconnect
........................................

If the *Note `mysql': mysql. client loses its connection to the server
while sending a statement, it immediately and automatically tries to
reconnect once to the server and send the statement again. However,
even if *Note `mysql': mysql. succeeds in reconnecting, your first
connection has ended and all your previous session objects and settings
are lost: temporary tables, the autocommit mode, and user-defined and
session variables. Also, any current transaction rolls back. This
behavior may be dangerous for you, as in the following example where
the server was shut down and restarted between the first and second
statements without you knowing it:

mysql> SET @a=1;
Query OK, 0 rows affected (0.05 sec)

mysql> INSERT INTO t VALUES(@a);
ERROR 2006: MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 1
Current database: test

Query OK, 1 row affected (1.30 sec)

mysql> SELECT * FROM t;
+------+
| a |
+------+
| NULL |
+------+
1 row in set (0.05 sec)

The `@a' user variable has been lost with the connection, and after the
reconnection it is undefined. If it is important to have *Note `mysql':
mysql. terminate with an error if the connection has been lost, you can
start the *Note `mysql': mysql. client with the `--skip-reconnect'
option.

For more information about auto-reconnect and its effect on state
information when a reconnection occurs, see *Note auto-reconnect::.

File: manual.info, Node: mysqladmin, Next: mysqlcheck, Prev: mysql, Up: programs-client

5.5.2 `mysqladmin' -- Client for Administering a MySQL Server
-------------------------------------------------------------

*Note `mysqladmin': mysqladmin. is a client for performing
administrative operations. You can use it to check the server's
configuration and current status, to create and drop databases, and
more.

Invoke *Note `mysqladmin': mysqladmin. like this:

shell> mysqladmin [OPTIONS] COMMAND [COMMAND-ARG] [COMMAND [COMMAND-ARG]] ...

*Note `mysqladmin': mysqladmin. supports the following commands. Some
of the commands take an argument following the command name.

* `create DB_NAME'

Create a new database named DB_NAME.

* `debug'

Tell the server to write debug information to the error log.

* `drop DB_NAME'

Delete the database named DB_NAME and all its tables.

* `extended-status'

Display the server status variables and their values.

* `flush-hosts'

Flush all information in the host cache.

* `flush-logs'

Flush all logs.

* `flush-privileges'

Reload the grant tables (same as `reload').

* `flush-status'

Clear status variables.

* `flush-tables'

Flush all tables.

* `flush-threads'

Flush the thread cache.

* `kill ID,ID,...'

Kill server threads. If multiple thread ID values are given, there
must be no spaces in the list.

* `old-password NEW-PASSWORD'

This is like the `password' command but stores the password using
the old (pre-4.1) password-hashing format. (See *Note
password-hashing::.)

* `password NEW-PASSWORD'

Set a new password. This changes the password to NEW-PASSWORD for
the account that you use with *Note `mysqladmin': mysqladmin. for
connecting to the server. Thus, the next time you invoke *Note
`mysqladmin': mysqladmin. (or any other client program) using the
same account, you will need to specify the new password.

If the NEW-PASSWORD value contains spaces or other characters that
are special to your command interpreter, you need to enclose it
within quotation marks. On Windows, be sure to use double
quotation marks rather than single quotation marks; single
quotation marks are not stripped from the password, but rather are
interpreted as part of the password. For example:

shell> mysqladmin password "my new password"

*Caution*:

Do not use this command used if the server was started with the
`--skip-grant-tables' option. No password change will be applied.
This is true even if you precede the `password' command with
`flush-privileges' on the same command line to re-enable the grant
tables because the flush operation occurs after you connect.
However, you can use *Note `mysqladmin flush-privileges':
mysqladmin. to re-enable the grant table and then use a separate
*Note `mysqladmin password': mysqladmin. command to change the
password.

* `ping'

Check whether the server is available. The return status from
*Note `mysqladmin': mysqladmin. is 0 if the server is running, 1
if it is not. This is 0 even in case of an error such as `Access
denied', because this means that the server is running but refused
the connection, which is different from the server not running.

* `processlist'

Show a list of active server threads. This is like the output of
the *Note `SHOW PROCESSLIST': show-processlist. statement. If the
`--verbose' option is given, the output is like that of *Note
`SHOW FULL PROCESSLIST': show-processlist. (See *Note
show-processlist::.)

* `reload'

Reload the grant tables.

* `refresh'

Flush all tables and close and open log files.

* `shutdown'

Stop the server.

* `start-slave'

Start replication on a slave server.

* `status'

Display a short server status message.

* `stop-slave'

Stop replication on a slave server.

* `variables'

Display the server system variables and their values.

* `version'

Display version information from the server.

All commands can be shortened to any unique prefix. For example:

The *Note `mysqladmin status': mysqladmin. command result displays the
following values:

* `Uptime'

The number of seconds the MySQL server has been running.

* `Threads'

The number of active threads (clients).

* `Questions'

The number of questions (queries) from clients since the server
was started.

* `Slow queries'

The number of queries that have taken more than `long_query_time'
seconds. See *Note slow-query-log::.

* `Opens'

The number of tables the server has opened.

* `Flush tables'

The number of `flush-*', `refresh', and `reload' commands the
server has executed.

* `Open tables'

The number of tables that currently are open.

* `Memory in use'

The amount of memory allocated directly by *Note `mysqld': mysqld.
This value is displayed only when MySQL has been compiled with
`--with-debug=full'.

* `Maximum memory used'

The maximum amount of memory allocated directly by *Note `mysqld':
mysqld. This value is displayed only when MySQL has been compiled
with `--with-debug=full'.

If you execute *Note `mysqladmin shutdown': mysqladmin. when connecting
to a local server using a Unix socket file, *Note `mysqladmin':
mysqladmin. waits until the server's process ID file has been removed,
to ensure that the server has stopped properly.

*Note `mysqladmin': mysqladmin. supports the following options, which
can be specified on the command line or in the `[mysqladmin]' and
`[client]' option file groups. *Note `mysqladmin': mysqladmin. also
supports the options for processing option files described at *Note
option-file-options::.

*`mysqladmin' Options*

Format Option File Description IntroductionDeprecatedRemoved
-compress compress Compress all information
sent between the client and
the server
-connect_timeout=secondsconnect_timeoutThe number of seconds before
connection timeout
-count=# count The number of iterations to
make for repeated command
execution
-debug[=debug_options]debug Write a debugging log
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-force force Continue even if an SQL
error occurs
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-password[=password]password The password to use when
connecting to the server
-pipe On Windows, connect to
server using a named pipe
-port=port_numport The TCP/IP port number to
use for the connection
-protocol=typeprotocol The connection protocol to
use
-relative relative Show the difference between
the current and previous
values when used with the
-sleep option
-shutdown_timeout=secondsshutdown_timeoutThe maximum number of
seconds to wait for server
shutdown
-silent silent Silent mode
-sleep=delaysleep Execute commands repeatedly,
sleeping for delay seconds
in between
-socket=pathsocket For connections to localhost
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-user=user_name,user The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit
-vertical vertical Print query output rows
vertically (one line per
column value)
-wait wait If the connection cannot be
established, wait and retry
instead of aborting

* `--help', `-?'

Display a help message and exit.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--compress', `-C'

Compress all information sent between the client and the server if
both support compression.

* `--count=N', `-c N'

The number of iterations to make for repeated command execution if
the `--sleep' option is given.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is
`'d:t:o,/tmp/mysqladmin.trace''.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set. See *Note
charset-configuration::.

* `--force', `-f'

Do not ask for confirmation for the `drop DB_NAME' command. With
multiple commands, continue even if an error occurs.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--relative', `-r'

Show the difference between the current and previous values when
used with the `--sleep' option. This option works only with the
`extended-status' command.

* `--silent', `-s'

Exit silently if a connection to the server cannot be established.

* `--sleep=DELAY', `-i DELAY'

Execute commands repeatedly, sleeping for DELAY seconds in
between. The `--count' option determines the number of iterations.
If `--count' is not given, *Note `mysqladmin': mysqladmin.
executes commands indefinitely until interrupted.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.

* `--version', `-V'

Display version information and exit.

* `--vertical', `-E'

Print output vertically. This is similar to `--relative', but
prints output vertically.

* `--wait[=COUNT]', `-w[COUNT]'

If the connection cannot be established, wait and retry instead of
aborting. If a COUNT value is given, it indicates the number of
times to retry. The default is one time.

You can also set the following variables by using `--VAR_NAME=VALUE'
The `--set-variable' format is deprecated. syntax:

* `connect_timeout'

The maximum number of seconds before connection timeout. The
default value is 43200 (12 hours).

* `shutdown_timeout'

The maximum number of seconds to wait for server shutdown. The
default value is 3600 (1 hour).

It is also possible to set variables by using `--VAR_NAME=VALUE'. The
`--set-variable' format is deprecated.

File: manual.info, Node: mysqlcheck, Next: mysqldump, Prev: mysqladmin, Up: programs-client

5.5.3 `mysqlcheck' -- A Table Maintenance Program
-------------------------------------------------

The *Note `mysqlcheck': mysqlcheck. client performs table maintenance:
It checks, repairs, optimizes, or analyzes tables.

Each table is locked and therefore unavailable to other sessions while
it is being processed, although for check operations, the table is
locked with a `READ' lock only (see *Note lock-tables::, for more
information about `READ' and `WRITE' locks). Table maintenance
operations can be time-consuming, particularly for large tables. If you
use the `--databases' or `--all-databases' option to process all tables
in one or more databases, an invocation of *Note `mysqlcheck':
mysqlcheck. might take a long time. (This is also true for *Note
`mysql_upgrade': mysql-upgrade. because that program invokes *Note
`mysqlcheck': mysqlcheck. to check all tables and repair them if
necessary.)

*Note `mysqlcheck': mysqlcheck. is similar in function to *Note
`myisamchk': myisamchk, but works differently. The main operational
difference is that *Note `mysqlcheck': mysqlcheck. must be used when
the *Note `mysqld': mysqld. server is running, whereas *Note
`myisamchk': myisamchk. should be used when it is not. The benefit of
using *Note `mysqlcheck': mysqlcheck. is that you do not have to stop
the server to perform table maintenance.

*Note `mysqlcheck': mysqlcheck. uses the SQL statements *Note `CHECK
TABLE': check-table, *Note `REPAIR TABLE': repair-table, *Note `ANALYZE
TABLE': analyze-table, and *Note `OPTIMIZE TABLE': optimize-table. in a
convenient way for the user. It determines which statements to use for
the operation you want to perform, and then sends the statements to the
server to be executed. For details about which storage engines each
statement works with, see the descriptions for those statements in
*Note table-maintenance-sql::.

The `MyISAM' storage engine supports all four maintenance operations,
so *Note `mysqlcheck': mysqlcheck. can be used to perform any of them
on `MyISAM' tables. Other storage engines do not necessarily support
all operations. In such cases, an error message is displayed. For
example, if `test.t' is a `MEMORY' table, an attempt to check it
produces this result:

shell> mysqlcheck test t
test.t
note : The storage engine for the table doesn't support check

If *Note `mysqlcheck': mysqlcheck. is unable to repair a table, see
*Note rebuilding-tables:: for manual table repair strategies. This will
be the case, for example, for `InnoDB' tables, which can be checked with
*Note `CHECK TABLE': check-table, but not repaired with *Note `REPAIR
TABLE': repair-table.

*Caution*:

It is best to make a backup of a table before performing a table repair
operation; under some circumstances the operation might cause data
loss. Possible causes include but are not limited to file system errors.

There are three general ways to invoke *Note `mysqlcheck': mysqlcheck.:

shell> mysqlcheck [OPTIONS] DB_NAME [TBL_NAME ...]
shell> mysqlcheck [OPTIONS] --databases DB_NAME ...
shell> mysqlcheck [OPTIONS] --all-databases

If you do not name any tables following DB_NAME or if you use the
`--databases' or `--all-databases' option, entire databases are checked.

*Note `mysqlcheck': mysqlcheck. has a special feature compared to other
client programs. The default behavior of checking tables (`--check')
can be changed by renaming the binary. If you want to have a tool that
repairs tables by default, you should just make a copy of *Note
`mysqlcheck': mysqlcheck. named `mysqlrepair', or make a symbolic link
to *Note `mysqlcheck': mysqlcheck. named `mysqlrepair'. If you invoke
`mysqlrepair', it repairs tables.

The names shown in the following table can be used to change *Note
`mysqlcheck': mysqlcheck. default behavior.

Command Meaning
`mysqlrepair' The default option is `--repair'
`mysqlanalyze' The default option is `--analyze'
`mysqloptimize' The default option is `--optimize'

*Note `mysqlcheck': mysqlcheck. supports the following options, which
can be specified on the command line or in the `[mysqlcheck]' and
`[client]' option file groups. *Note `mysqlcheck': mysqlcheck. also
supports the options for processing option files described at *Note
option-file-options::.

*`mysqlcheck' Options*

Format Option File Description IntroductionDeprecatedRemoved
-all-databasesall-databasesCheck all tables in all
databases
-all-in-1 all-in-1 Execute a single statement
for each database that names
all the tables from that
database
-analyze analyze Analyze the tables
-auto-repairauto-repair If a checked table is
corrupted, automatically fix
it
-character-sets-dir=pathcharacter-sets-dirThe directory where
character sets are installed
-check check Check the tables for errors
-check-only-changedcheck-only-changedCheck only tables that have
changed since the last check
-check-upgradecheck-upgradeInvoke CHECK TABLE with the 5.0.19
FOR UPGRADE option
-compress compress Compress all information
sent between the client and
the server
-databases databases Process all tables in the
named databases
-debug[=debug_options]debug Write a debugging log
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-extended extended Check and repair tables
-fast fast Check only tables that have
not been closed properly
-force force Continue even if an SQL
error occurs
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-medium-checkmedium-checkDo a check that is faster
than an -extended operation
-optimize optimize Optimize the tables
-password[=password]password The password to use when
connecting to the server
-pipe On Windows, connect to
server using a named pipe
-port=port_numport The TCP/IP port number to
use for the connection
-protocol=typeprotocol The connection protocol to
use
-quick quick The fastest method of
checking
-repair repair Perform a repair that can
fix almost anything except
unique keys that are not
unique
-silent silent Silent mode
-socket=pathsocket For connections to localhost
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-tables tables Overrides the -databases or
-B option
-use-frm use-frm For repair operations on
MyISAM tables
-user=user_name,user The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit

* `--help', `-?'

Display a help message and exit.

* `--all-databases', `-A'

Check all tables in all databases. This is the same as using the
`--databases' option and naming all the databases on the command
line.

* `--all-in-1', `-1'

Instead of issuing a statement for each table, execute a single
statement for each database that names all the tables from that
database to be processed.

* `--analyze', `-a'

Analyze the tables.

* `--auto-repair'

If a checked table is corrupted, automatically fix it. Any
necessary repairs are done after all tables have been checked.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--check', `-c'

Check the tables for errors. This is the default operation.

* `--check-only-changed', `-C'

Check only tables that have changed since the last check or that
have not been closed properly.

* `--check-upgrade', `-g'

Invoke *Note `CHECK TABLE': check-table. with the `FOR UPGRADE'
option to check tables for incompatibilities with the current
version of the server. This option was added in MySQL 5.0.19.

* `--compress'

Compress all information sent between the client and the server if
both support compression.

* `--databases', `-B'

Process all tables in the named databases. Normally, *Note
`mysqlcheck': mysqlcheck. treats the first name argument on the
command line as a database name and following names as table
names. With this option, it treats all name arguments as database
names.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is `'d:t:o''.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set. See *Note
charset-configuration::.

* `--extended', `-e'

If you are using this option to check tables, it ensures that they
are 100% consistent but takes a long time.

If you are using this option to repair tables, it runs an extended
repair that may not only take a long time to execute, but may
produce a lot of garbage rows also!

* `--fast', `-F'

Check only tables that have not been closed properly.

* `--force', `-f'

Continue even if an SQL error occurs.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--medium-check', `-m'

Do a check that is faster than an `--extended' operation. This
finds only 99.99% of all errors, which should be good enough in
most cases.

* `--optimize', `-o'

Optimize the tables.

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--quick', `-q'

If you are using this option to check tables, it prevents the
check from scanning the rows to check for incorrect links. This is
the fastest check method.

If you are using this option to repair tables, it tries to repair
only the index tree. This is the fastest repair method.

* `--repair', `-r'

Perform a repair that can fix almost anything except unique keys
that are not unique.

* `--silent', `-s'

Silent mode. Print only error messages.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--tables'

Override the `--databases' or `-B' option. All name arguments
following the option are regarded as table names.

* `--use-frm'

For repair operations on `MyISAM' tables, get the table structure
from the `.frm' file so that the table can be repaired even if the
`.MYI' header is corrupted.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Print information about the various stages of
program operation.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: mysqldump, Next: mysqlimport, Prev: mysqlcheck, Up: programs-client

5.5.4 `mysqldump' -- A Database Backup Program
----------------------------------------------

The *Note `mysqldump': mysqldump. client is a backup program originally
written by Igor Romanenko. It can be used to dump a database or a
collection of databases for backup or transfer to another SQL server
(not necessarily a MySQL server). The dump typically contains SQL
statements to create the table, populate it, or both. However, *Note
`mysqldump': mysqldump. can also be used to generate files in CSV,
other delimited text, or XML format.

If you are doing a backup on the server and your tables all are
`MyISAM' tables, consider using the *Note `mysqlhotcopy': mysqlhotcopy.
instead because it can accomplish faster backups and faster restores.
See *Note mysqlhotcopy::.

There are three general ways to invoke *Note `mysqldump': mysqldump.:

shell> mysqldump [OPTIONS] DB_NAME [TBL_NAME ...]
shell> mysqldump [OPTIONS] --databases DB_NAME ...
shell> mysqldump [OPTIONS] --all-databases

If you do not name any tables following DB_NAME or if you use the
`--databases' or `--all-databases' option, entire databases are dumped.

*Note `mysqldump': mysqldump. does not dump the `INFORMATION_SCHEMA'
database. If you name that database explicitly on the command line,
*Note `mysqldump': mysqldump. silently ignores it.

To see a list of the options your version of *Note `mysqldump':
mysqldump. supports, execute *Note `mysqldump --help': mysqldump.

Some *Note `mysqldump': mysqldump. options are shorthand for groups of
other options:

* Use of `--opt' is the same as specifying `--add-drop-table',
`--add-locks', `--create-options', `--disable-keys',
`--extended-insert', `--lock-tables', `--quick', and
`--set-charset'. All of the options that `--opt' stands for also
are on by default because `--opt' is on by default.

* Use of `--compact' is the same as specifying
`--skip-add-drop-table', `--skip-add-locks', `--skip-comments',
`--skip-disable-keys', and `--skip-set-charset' options.

To reverse the effect of a group option, uses its `--skip-XXX' form
(`--skip-opt' or `--skip-compact'). It is also possible to select only
part of the effect of a group option by following it with options that
enable or disable specific features. Here are some examples:

* To select the effect of `--opt' except for some features, use the
`--skip' option for each feature. To disable extended inserts and
memory buffering, use `--opt' `--skip-extended-insert'
`--skip-quick'. (Actually, `--skip-extended-insert' `--skip-quick'
is sufficient because `--opt' is on by default.)

* To reverse `--opt' for all features except index disabling and
table locking, use `--skip-opt' `--disable-keys' `--lock-tables'.

When you selectively enable or disable the effect of a group option,
order is important because options are processed first to last. For
example, `--disable-keys' `--lock-tables' `--skip-opt' would not have
the intended effect; it is the same as `--skip-opt' by itself.

*Note `mysqldump': mysqldump. can retrieve and dump table contents row
by row, or it can retrieve the entire content from a table and buffer
it in memory before dumping it. Buffering in memory can be a problem if
you are dumping large tables. To dump tables row by row, use the
`--quick' option (or `--opt', which enables `--quick'). The `--opt'
option (and hence `--quick') is enabled by default, so to enable memory
buffering, use `--skip-quick'.

If you are using a recent version of *Note `mysqldump': mysqldump. to
generate a dump to be reloaded into a very old MySQL server, you should
not use the `--opt' or `--extended-insert' option. Use `--skip-opt'
instead.

Before MySQL 4.1.2, out-of-range numeric values such as `-inf' and
`inf', as well as `NaN' (not-a-number) values are dumped by *Note
`mysqldump': mysqldump. as `NULL'. You can see this using the following
sample table:

mysql> CREATE TABLE t (f DOUBLE);
mysql> INSERT INTO t VALUES(1e+111111111111111111111);
mysql> INSERT INTO t VALUES(-1e111111111111111111111);
mysql> SELECT f FROM t;
+------+
| f |
+------+
| inf |
| -inf |
+------+

For this table, *Note `mysqldump': mysqldump. produces the following
data output:

--
-- Dumping data for table `t`
--

INSERT INTO t VALUES (NULL);
INSERT INTO t VALUES (NULL);

The significance of this behavior is that if you dump and restore the
table, the new table has contents that differ from the original
contents. This problem is fixed as of MySQL 4.1.2; you cannot insert
`inf' in the table, so this *Note `mysqldump': mysqldump. behavior is
only relevant when you deal with old servers.

For additional information about *Note `mysqldump': mysqldump, see
*Note using-mysqldump::.

*Note `mysqldump': mysqldump. supports the following options, which can
be specified on the command line or in the `[mysqldump]' and `[client]'
option file groups. *Note `mysqldump': mysqldump. also supports the
options for processing option files described at *Note
option-file-options::.

*`mysqldump' Options*

Format Option File Description IntroductionDeprecatedRemoved
-add-drop-databaseadd-drop-databaseAdd a DROP DATABASE
statement before each CREATE
DATABASE statement
-add-drop-tableadd-drop-tableAdd a DROP TABLE statement
before each CREATE TABLE
statement
-add-locks add-locks Surround each table dump
with LOCK TABLES and UNLOCK
TABLES statements
-all-databasesall-databasesDump all tables in all
databases
-allow-keywordsallow-keywordsAllow creation of column
names that are keywords
-comments comments Add comments to the dump file
-compact compact Produce more compact output
-compatible=name[,name,...]compatible Produce output that is more
compatible with other
database systems or with
older MySQL servers
-complete-insertcomplete-insertUse complete INSERT
statements that include
column names
-create-optionscreate-optionsInclude all MySQL-specific
table options in CREATE
TABLE statements
-databases databases Dump several databases
-debug[=debug_options]debug Write a debugging log
-debug-info debug-info Print debugging information, 5.0.32
memory and CPU statistics
when the program exits
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-delayed-insertdelayed-insertWrite INSERT DELAYED
statements rather than
INSERT statements
-delete-master-logsdelete-master-logsOn a master replication
server, delete the binary
logs after performing the
dump operation
-disable-keysdisable-keysFor each table, surround the
INSERT statements with
statements to disable and
enable keys
-dump-date dump-date Include dump date as "Dump 5.0.52
completed on" comment if
-comments is given
-extended-insertextended-insertUse multiple-row INSERT
syntax that include several
VALUES lists
-fields-enclosed-by=stringfields-enclosed-byThis option is used with the
-tab option and has the same
meaning as the
corresponding clause for
LOAD DATA INFILE
-fields-escaped-byfields-escaped-byThis option is used with the
-tab option and has the same
meaning as the
corresponding clause for
LOAD DATA INFILE
-fields-optionally-enclosed-by=stringfields-optionally-enclosed-byThis option is used with the
-tab option and has the same
meaning as the
corresponding clause for
LOAD DATA INFILE
-fields-terminated-by=stringfields-terminated-byThis option is used with the
-tab option and has the same
meaning as the
corresponding clause for
LOAD DATA INFILE
-first-slavefirst-slave Deprecated; use
-lock-all-tables instead
-flush-logs flush-logs Flush the MySQL server log
files before starting the
dump
-flush-privilegesflush-privilegesEmit a FLUSH PRIVILEGES
statement after dumping the
mysql database
-help Display help message and exit
-hex-blob hex-blob Dump binary columns using
hexadecimal notation (for
example, 'abc' becomes
0x616263)
-host host Host to connect to (IP
address or hostname)
-ignore-table=db_name.tbl_nameignore-tableDo not dump the given table
-insert-ignoreinsert-ignoreWrite INSERT IGNORE
statements rather than
INSERT statements
-lines-terminated-by=stringlines-terminated-byThis option is used with the
-tab option and has the same
meaning as the
corresponding clause for
LOAD DATA INFILE
-lock-all-tableslock-all-tablesLock all tables across all
databases
-lock-tableslock-tables Lock all tables before
dumping them
-log-error=file_namelog-error Append warnings and errors 5.0.42
to the named file
-master-data[=value]master-data Write the binary log file
name and position to the
output
-max_allowed_packet=valuemax_allowed_packetThe maximum packet length to
send to or receive from the
server
-net_buffer_length=valuenet_buffer_lengthThe buffer size for TCP/IP
and socket communication
-no-autocommitno-autocommitEnclose the INSERT
statements for each dumped
table within SET autocommit
= 0 and COMMIT statements
-no-create-dbno-create-dbThis option suppresses the
CREATE DATABASE statements
-no-create-infono-create-infoDo not write CREATE TABLE
statements that re-create
each dumped table
-no-data no-data Do not dump table contents
-no-set-namesno-set-namesSame as -skip-set-charset
-opt opt Shorthand for
-add-drop-table -add-locks
-create-options
-disable-keys
-extended-insert
-lock-tables -quick
-set-charset.
-order-by-primaryorder-by-primaryDump each table's rows
sorted by its primary key,
or by its first unique index
-password[=password]password The password to use when
connecting to the server
-pipe On Windows, connect to
server using a named pipe
-port=port_numport The TCP/IP port number to
use for the connection
-quick quick Retrieve rows for a table
from the server a row at a
time
-quote-namesquote-names Quote identifiers within
backtick characters
-result-file=fileresult-file Direct output to a given file
-routines routines Dump stored routines 5.0.13
(procedures and functions)
from the dumped databases
-set-charsetset-charset Add SET NAMES
default_character_set to the
output
-single-transactionsingle-transactionThis option issues a BEGIN
SQL statement before dumping
data from the server
-skip-add-drop-tableskip-add-drop-tableDo not add a DROP TABLE
statement before each CREATE
TABLE statement
-skip-add-locksskip-add-locksDo not add locks
-skip-commentsskip-commentsDo not add comments to the
dump file
-skip-compactskip-compactDo not produce more compact
output
-skip-disable-keysskip-disable-keysDo not disable keys
-skip-extended-insertskip-extended-insertTurn off extended-insert
-skip-opt skip-opt Turn off the options set by
-opt
-skip-quick skip-quick Do not retrieve rows for a
table from the server a row
at a time
-skip-quote-namesskip-quote-namesDo not quote identifiers
-skip-set-charsetskip-set-charsetSuppress the SET NAMES
statement
-skip-triggersskip-triggersDo not dump triggers 5.0.11
-skip-tz-utcskip-tz-utc Turn off tz-utc 5.0.15
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-tab=path tab Produce tab-separated data
files
-tables tables Override the -databases or
-B option
-triggers triggers Dump triggers for each
dumped table
-tz-utc tz-utc Add SET TIME_ZONE='+00:00' 5.0.15
to the dump file
-user=user_nameuser The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit
-where='where_condition'where Dump only rows selected by
the given WHERE condition
-xml xml Produce XML output

* `--help', `-?'

Display a help message and exit.

* `--add-drop-database'

Add a *Note `DROP DATABASE': drop-database. statement before each
*Note `CREATE DATABASE': create-database. statement. This option
is typically used in conjunction with the `--all-databases' or
`--databases' option because no *Note `CREATE DATABASE':
create-database. statements are written unless one of those
options is specified.

* `--add-drop-table'

Add a *Note `DROP TABLE': drop-table. statement before each *Note
`CREATE TABLE': create-table. statement.

* `--add-locks'

Surround each table dump with *Note `LOCK TABLES': lock-tables. and
*Note `UNLOCK TABLES': lock-tables. statements. This results in
faster inserts when the dump file is reloaded. See *Note
insert-speed::.

* `--all-databases', `-A'

Dump all tables in all databases. This is the same as using the
`--databases' option and naming all the databases on the command
line.

* `--allow-keywords'

Permit creation of column names that are keywords. This works by
prefixing each column name with the table name.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--comments', `-i'

Write additional information in the dump file such as program
version, server version, and host. This option is enabled by
default. To suppress this additional information, use
`--skip-comments'.

* `--compact'

Produce more compact output. This option enables the
`--skip-add-drop-table', `--skip-add-locks', `--skip-comments',
`--skip-disable-keys', and `--skip-set-charset' options.

*Note*:

Prior to MySQL 5.0.48, this option did not create valid SQL if the
database dump contained views. The recreation of views requires
the creation and removal of temporary tables and this option
suppressed the removal of those temporary tables. As a workaround,
use `--compact' with the `--add-drop-table' option and then
manually adjust the dump file.

* `--compatible=NAME'

Produce output that is more compatible with other database systems
or with older MySQL servers. The value of NAME can be `ansi',
`mysql323', `mysql40', `postgresql', `oracle', `mssql', `db2',
`maxdb', `no_key_options', `no_table_options', or
`no_field_options'. To use several values, separate them by
commas. These values have the same meaning as the corresponding
options for setting the server SQL mode. See *Note
server-sql-mode::.

This option does not guarantee compatibility with other servers.
It only enables those SQL mode values that are currently available
for making dump output more compatible. For example,
`--compatible=oracle' does not map data types to Oracle types or
use Oracle comment syntax.

_This option requires a server version of 4.1.0 or higher_. With
older servers, it does nothing.

* `--complete-insert', `-c'

Use complete *Note `INSERT': insert. statements that include
column names.

* `--compress', `-C'

Compress all information sent between the client and the server if
both support compression.

* `--create-options'

Include all MySQL-specific table options in the *Note `CREATE
TABLE': create-table. statements.

* `--databases', `-B'

Dump several databases. Normally, *Note `mysqldump': mysqldump.
treats the first name argument on the command line as a database
name and following names as table names. With this option, it
treats all name arguments as database names. *Note `CREATE
DATABASE': create-database. and *Note `USE': use. statements are
included in the output before each new database.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default value is
`'d:t:o,/tmp/mysqldump.trace''.

* `--debug-info'

Print debugging information and memory and CPU usage statistics
when the program exits. This option was added in MySQL 5.0.32.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set. See *Note
charset-configuration::. If no character set is specified, *Note
`mysqldump': mysqldump. uses `utf8', and earlier versions use
`latin1'.

This option has no effect for output data files produced by using
the `--tab' option. See the description for that option.

* `--delayed-insert'

Write *Note `INSERT DELAYED': insert-delayed. statements rather
than *Note `INSERT': insert. statements.

* `--delete-master-logs'

On a master replication server, delete the binary logs by sending
a *Note `PURGE BINARY LOGS': purge-binary-logs. statement to the
server after performing the dump operation. This option
automatically enables `--master-data'.

* `--disable-keys', `-K'

For each table, surround the *Note `INSERT': insert. statements
with `/*!40000 ALTER TABLE TBL_NAME DISABLE KEYS */;' and
`/*!40000 ALTER TABLE TBL_NAME ENABLE KEYS */;' statements. This
makes loading the dump file faster because the indexes are created
after all rows are inserted. This option is effective only for
nonunique indexes of `MyISAM' tables.

* `--dump-date'

If the `--comments' option is given, *Note `mysqldump': mysqldump.
produces a comment at the end of the dump of the following form:

-- Dump completed on DATE

However, the date causes dump files taken at different times to
appear to be different, even if the data are otherwise identical.
`--dump-date' and `--skip-dump-date' control whether the date is
added to the comment. The default is `--dump-date' (include the
date in the comment). `--skip-dump-date' suppresses date
printing. This option was added in MySQL 5.0.52.

* `--extended-insert', `-e'

Use multiple-row *Note `INSERT': insert. syntax that include
several `VALUES' lists. This results in a smaller dump file and
speeds up inserts when the file is reloaded.

* `--fields-terminated-by=...',

`--fields-enclosed-by=...',

`--fields-optionally-enclosed-by=...',

`--fields-escaped-by=...'

These options are used with the `--tab' option and have the same
meaning as the corresponding `FIELDS' clauses for *Note `LOAD DATA
INFILE': load-data. See *Note load-data::.

* `--first-slave'

Deprecated. Use `--lock-all-tables' instead. `--first-slave' is
removed in MySQL 5.5.

* `--flush-logs', `-F'

Flush the MySQL server log files before starting the dump. This
option requires the `RELOAD' privilege. If you use this option in
combination with the `--all-databases' option, the logs are
flushed _for each database dumped_. The exception is when using
`--lock-all-tables' or `--master-data': In this case, the logs are
flushed only once, corresponding to the moment that all tables are
locked. If you want your dump and the log flush to happen at
exactly the same moment, you should use `--flush-logs' together
with either `--lock-all-tables' or `--master-data'.

* `--flush-privileges'

Send a *Note `FLUSH PRIVILEGES': flush. statement to the server
after dumping the `mysql' database. This option should be used any
time the dump contains the `mysql' database and any other database
that depends on the data in the `mysql' database for proper
restoration. This option was added in MySQL 5.0.26.

* `--force', `-f'

Continue even if an SQL error occurs during a table dump.

One use for this option is to cause *Note `mysqldump': mysqldump.
to continue executing even when it encounters a view that has
become invalid because the definition refers to a table that has
been dropped. Without `--force', *Note `mysqldump': mysqldump.
exits with an error message. With `--force', *Note `mysqldump':
mysqldump. prints the error message, but it also writes an SQL
comment containing the view definition to the dump output and
continues executing.

* `--host=HOST_NAME', `-h HOST_NAME'

Dump data from the MySQL server on the given host. The default
host is `localhost'.

* `--hex-blob'

Dump binary columns using hexadecimal notation (for example,
`'abc'' becomes `0x616263'). The affected data types are *Note
`BINARY': binary-varbinary, *Note `VARBINARY': binary-varbinary,
and the *Note `BLOB': blob. types. As of MySQL 5.0.13, *Note
`BIT': numeric-types. columns are affected as well.

* `--ignore-table=DB_NAME.TBL_NAME'

Do not dump the given table, which must be specified using both
the database and table names. To ignore multiple tables, use this
option multiple times. This option also can be used to ignore
views.

* `--insert-ignore'

Write *Note `INSERT IGNORE': insert. statements rather than *Note
`INSERT': insert. statements.

* `--lines-terminated-by=...'

This option is used with the `--tab' option and has the same
meaning as the corresponding `LINES' clause for *Note `LOAD DATA
INFILE': load-data. See *Note load-data::.

* `--lock-all-tables', `-x'

Lock all tables across all databases. This is achieved by
acquiring a global read lock for the duration of the whole dump.
This option automatically turns off `--single-transaction' and
`--lock-tables'.

* `--lock-tables', `-l'

For each dumped database, lock all tables to be dumped before
dumping them. The tables are locked with `READ LOCAL' to permit
concurrent inserts in the case of `MyISAM' tables. For
transactional tables such as `InnoDB' and `BDB',
`--single-transaction' is a much better option than
`--lock-tables' because it does not need to lock the tables at all.

Because `--lock-tables' locks tables for each database separately,
this option does not guarantee that the tables in the dump file
are logically consistent between databases. Tables in different
databases may be dumped in completely different states.

* `--log-error=FILE_NAME'

Log warnings and errors by appending them to the named file. The
default is to do no logging. This option was added in MySQL 5.0.42.

* `--master-data[=VALUE]'

Use this option to dump a master replication server to produce a
dump file that can be used to set up another server as a slave of
the master. It causes the dump output to include a *Note `CHANGE
MASTER TO': change-master-to. statement that indicates the binary
log coordinates (file name and position) of the dumped server.
These are the master server coordinates from which the slave
should start replicating after you load the dump file into the
slave.

If the option value is 2, the *Note `CHANGE MASTER TO':
change-master-to. statement is written as an SQL comment, and thus
is informative only; it has no effect when the dump file is
reloaded. If the option value is 1, the statement is not written
as a comment and takes effect when the dump file is reloaded. If
no option value is specified, the default value is 1.

This option requires the `RELOAD' privilege and the binary log
must be enabled.

The `--master-data' option automatically turns off
`--lock-tables'. It also turns on `--lock-all-tables', unless
`--single-transaction' also is specified, in which case, a global
read lock is acquired only for a short time at the beginning of
the dump (see the description for `--single-transaction'). In all
cases, any action on logs happens at the exact moment of the dump.

It is also possible to set up a slave by dumping an existing slave
of the master. To do this, use the following procedure on the
existing slave:

1. Stop the slave's SQL thread and get its current status:

mysql> STOP SLAVE SQL_THREAD;
mysql> SHOW SLAVE STATUS;

2. From the output of the *Note `SHOW SLAVE STATUS':
show-slave-status. statement, the binary log coordinates of
the master server from which the new slave should start
replicating are the values of the `Relay_Master_Log_File' and
`Exec_Master_Log_Pos' fields. Denote those values as
FILE_NAME and FILE_POS.

3. Dump the slave server:

shell> mysqldump --master-data=2 --all-databases > dumpfile

4. Restart the slave:

mysql> START SLAVE;

5. On the new slave, load the dump file:

shell> mysql < dumpfile

6. On the new slave, set the replication coordinates to those of
the master server obtained earlier:

mysql> CHANGE MASTER TO
-> MASTER_LOG_FILE = 'FILE_NAME', MASTER_LOG_POS = FILE_POS;

The *Note `CHANGE MASTER TO': change-master-to. statement
might also need other parameters, such as `MASTER_HOST' to
point the slave to the correct master server host. Add any
such parameters as necessary.

* `--no-autocommit'

Enclose the *Note `INSERT': insert. statements for each dumped
table within `SET autocommit = 0' and *Note `COMMIT': commit.
statements.

* `--no-create-db', `-n'

This option suppresses the *Note `CREATE DATABASE':
create-database. statements that are otherwise included in the
output if the `--databases' or `--all-databases' option is given.

* `--no-create-info', `-t'

Do not write *Note `CREATE TABLE': create-table. statements that
re-create each dumped table.

* `--no-data', `-d'

Do not write any table row information (that is, do not dump table
contents). This is useful if you want to dump only the *Note
`CREATE TABLE': create-table. statement for the table (for
example, to create an empty copy of the table by loading the dump
file).

* `--no-set-names', `-N'

This has the same effect as `--skip-set-charset'.

* `--opt'

This option is shorthand. It is the same as specifying
`--add-drop-table' `--add-locks' `--create-options'
`--disable-keys' `--extended-insert' `--lock-tables' `--quick'
`--set-charset'. It should give you a fast dump operation and
produce a dump file that can be reloaded into a MySQL server
quickly.

_The `--opt' option is enabled by default. Use `--skip-opt' to
disable it._ See the discussion at the beginning of this section
for information about selectively enabling or disabling a subset
of the options affected by `--opt'.

* `--order-by-primary'

Dump each table's rows sorted by its primary key, or by its first
unique index, if such an index exists. This is useful when dumping
a `MyISAM' table to be loaded into an `InnoDB' table, but will
make the dump operation take considerably longer.

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--quick', `-q'

This option is useful for dumping large tables. It forces *Note
`mysqldump': mysqldump. to retrieve rows for a table from the
server a row at a time rather than retrieving the entire row set
and buffering it in memory before writing it out.

* `--quote-names', `-Q'

Quote identifiers (such as database, table, and column names)
within ```'' characters. If the `ANSI_QUOTES' SQL mode is enabled,
identifiers are quoted within ``"'' characters. This option is
enabled by default. It can be disabled with `--skip-quote-names',
but this option should be given after any option such as
`--compatible' that may enable `--quote-names'.

* `--result-file=FILE_NAME', `-r FILE_NAME'

Direct output to a given file. This option should be used on
Windows to prevent newline ``\n'' characters from being converted
to ``\r\n'' carriage return/newline sequences. The result file is
created and its previous contents overwritten, even if an error
occurs while generating the dump.

* `--routines', `-R'

Included stored routines (procedures and functions) for the dumped
databases in the output. Use of this option requires the `SELECT'
privilege for the `mysql.proc' table. The output generated by
using `--routines' contains *Note `CREATE PROCEDURE':
create-procedure. and *Note `CREATE FUNCTION': create-function.
statements to re-create the routines. However, these statements do
not include attributes such as the routine creation and
modification timestamps. This means that when the routines are
reloaded, they will be created with the timestamps equal to the
reload time.

If you require routines to be re-created with their original
timestamp attributes, do not use `--routines'. Instead, dump and
reload the contents of the `mysql.proc' table directly, using a
MySQL account that has appropriate privileges for the `mysql'
database.

This option was added in MySQL 5.0.13. Before that, stored
routines are not dumped. Routine `DEFINER' values are not dumped
until MySQL 5.0.20. This means that before 5.0.20, when routines
are reloaded, they will be created with the definer set to the
reloading user. If you require routines to be re-created with
their original definer, dump and load the contents of the
`mysql.proc' table directly as described earlier.

* `--set-charset'

Add `SET NAMES DEFAULT_CHARACTER_SET' to the output. This option
is enabled by default. To suppress the `SET NAMES' statement, use
`--skip-set-charset'.

* `--single-transaction'

This option sends a *Note `START TRANSACTION': commit. SQL
statement to the server before dumping data. It is useful only
with transactional tables such as `InnoDB' and `BDB', because then
it dumps the consistent state of the database at the time when
*Note `BEGIN': commit. was issued without blocking any
applications.

When using this option, you should keep in mind that only `InnoDB'
tables are dumped in a consistent state. For example, any `MyISAM'
or `MEMORY' tables dumped while using this option may still change
state.

While a `--single-transaction' dump is in process, to ensure a
valid dump file (correct table contents and binary log
coordinates), no other connection should use the following
statements: *Note `ALTER TABLE': alter-table, *Note `CREATE
TABLE': create-table, *Note `DROP TABLE': drop-table, *Note
`RENAME TABLE': rename-table, *Note `TRUNCATE TABLE':
truncate-table. A consistent read is not isolated from those
statements, so use of them on a table to be dumped can cause the
*Note `SELECT': select. that is performed by *Note `mysqldump':
mysqldump. to retrieve the table contents to obtain incorrect
contents or fail.

The `--single-transaction' option and the `--lock-tables' option
are mutually exclusive because *Note `LOCK TABLES': lock-tables.
causes any pending transactions to be committed implicitly.

This option is not supported for MySQL Cluster tables; the results
cannot be guaranteed to be consistent due to the fact that the
*Note `NDBCLUSTER': mysql-cluster. storage engine supports only
the `READ_COMMITTED' transaction isolation level. You should
always use *Note `NDB': mysql-cluster. backup and restore instead.

To dump large tables, you should combine the `--single-transaction'
option with `--quick'.

* `--skip-comments'

See the description for the `--comments' option.

* `--skip-opt'

See the description for the `--opt' option.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--tab=PATH', `-T PATH'

Produce tab-separated text-format data files. For each dumped
table, *Note `mysqldump': mysqldump. creates a `TBL_NAME.sql' file
that contains the *Note `CREATE TABLE': create-table. statement
that creates the table, and the server writes a `TBL_NAME.txt'
file that contains its data. The option value is the directory in
which to write the files.

*Note*:

This option should be used only when *Note `mysqldump': mysqldump.
is run on the same machine as the *Note `mysqld': mysqld. server.
You must have the `FILE' privilege, and the server must have
permission to write files in the directory that you specify.

By default, the `.txt' data files are formatted using tab
characters between column values and a newline at the end of each
line. The format can be specified explicitly using the
`--fields-XXX' and `--lines-terminated-by' options.

Column values are dumped using the `binary' character set and the
`--default-character-set' option is ignored. In effect, there is
no character set conversion. If a table contains columns in
several character sets, the output data file will as well and you
may not be able to reload the file correctly.

* `--tables'

Override the `--databases' or `-B' option. *Note `mysqldump':
mysqldump. regards all name arguments following the option as
table names.

* `--triggers'

Include triggers for each dumped table in the output. This option
is enabled by default; disable it with `--skip-triggers'. This
option was added in MySQL 5.0.11. Before that, triggers are not
dumped.

* `--tz-utc'

This option enables *Note `TIMESTAMP': datetime. columns to be
dumped and reloaded between servers in different time zones. *Note
`mysqldump': mysqldump. sets its connection time zone to UTC and
adds `SET TIME_ZONE='+00:00'' to the dump file. Without this
option, *Note `TIMESTAMP': datetime. columns are dumped and
reloaded in the time zones local to the source and destination
servers, which can cause the values to change if the servers are
in different time zones. `--tz-utc' also protects against changes
due to daylight saving time. `--tz-utc' is enabled by default. To
disable it, use `--skip-tz-utc'. This option was added in MySQL
5.0.15.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.

* `--version', `-V'

Display version information and exit.

* `--where='WHERE_CONDITION'', `-w 'WHERE_CONDITION''

Dump only rows selected by the given `WHERE' condition. Quotes
around the condition are mandatory if it contains spaces or other
characters that are special to your command interpreter.

Examples:

--where="user='jimf'"
-w"userid>1"
-w"userid<1"

* `--xml', `-X'

Write dump output as well-formed XML.

*`NULL', `'NULL'', and Empty Values*: For a column named
COLUMN_NAME, the `NULL' value, an empty string, and the string
value `'NULL'' are distinguished from one another in the output
generated by this option as follows.

Value: XML Representation:
`NULL' (_unknown value_) `<field name="COLUMN_NAME"
xsi:nil="true" />'
`''' (_empty string_) `<field
name="COLUMN_NAME"></field>'
`'NULL'' (_string value_) `<field
name="COLUMN_NAME">NULL</field>'

Beginning with MySQL 5.0.26, the output from the *Note `mysql':
mysql. client when run using the `--xml' option also follows the
preceding rules. (See *Note mysql-command-options::.)

Beginning with MySQL 5.0.40, XML output from *Note `mysqldump':
mysqldump. includes the XML namespace, as shown here:

shell> mysqldump --xml -u root world City
<?xml version="1.0"?>
<mysqldump xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<database name="world">
<table_structure name="City">
<field Field="ID" Type="int(11)" Null="NO" Key="PRI" Extra="auto_increment" />
<field Field="Name" Type="char(35)" Null="NO" Key="" Default="" Extra="" />
<field Field="CountryCode" Type="char(3)" Null="NO" Key="" Default="" Extra="" />
<field Field="District" Type="char(20)" Null="NO" Key="" Default="" Extra="" />
<field Field="Population" Type="int(11)" Null="NO" Key="" Default="0" Extra="" />
<key Table="City" Non_unique="0" Key_name="PRIMARY" Seq_in_index="1" Column_name="ID"
Collation="A" Cardinality="4079" Null="" Index_type="BTREE" Comment="" />
<options Name="City" Engine="MyISAM" Version="10" Row_format="Fixed" Rows="4079"
Avg_row_length="67" Data_length="273293" Max_data_length="18858823439613951"
Index_length="43008" Data_free="0" Auto_increment="4080"
Create_time="2007-03-31 01:47:01" Update_time="2007-03-31 01:47:02"
Collation="latin1_swedish_ci" Create_options="" Comment="" />
</table_structure>
<table_data name="City">
<row>
<field name="ID">1</field>
<field name="Name">Kabul</field>
<field name="CountryCode">AFG</field>
<field name="District">Kabol</field>
<field name="Population">1780000</field>
</row>

...

<row>
<field name="ID">4079</field>
<field name="Name">Rafah</field>
<field name="CountryCode">PSE</field>
<field name="District">Rafah</field>
<field name="Population">92020</field>
</row>
</table_data>
</database>
</mysqldump>

You can also set the following variables by using `--VAR_NAME=VALUE'
syntax:

* `max_allowed_packet'

The maximum size of the buffer for client/server communication.
The maximum is 1GB.

* `net_buffer_length'

The initial size of the buffer for client/server communication.
When creating multiple-row *Note `INSERT': insert. statements (as
with the `--extended-insert' or `--opt' option), *Note
`mysqldump': mysqldump. creates rows up to `net_buffer_length'
length. If you increase this variable, you should also ensure that
the `net_buffer_length' variable in the MySQL server is at least
this large.

It is also possible to set variables by using `--VAR_NAME=VALUE'. The
`--set-variable' format is deprecated.

A common use of *Note `mysqldump': mysqldump. is for making a backup of
an entire database:

shell> mysqldump DB_NAME > BACKUP-FILE.SQL

You can load the dump file back into the server like this:

shell> mysql DB_NAME < BACKUP-FILE.SQL

Or like this:

shell> mysql -e "source /PATH-TO-BACKUP/BACKUP-FILE.SQL" DB_NAME

*Note `mysqldump': mysqldump. is also very useful for populating
databases by copying data from one MySQL server to another:

shell> mysqldump --opt DB_NAME | mysql --host=REMOTE_HOST -C DB_NAME

It is possible to dump several databases with one command:

shell> mysqldump --databases DB_NAME1 [DB_NAME2 ...] > my_databases.sql

To dump all databases, use the `--all-databases' option:

shell> mysqldump --all-databases > all_databases.sql

For `InnoDB' tables, *Note `mysqldump': mysqldump. provides a way of
making an online backup:

shell> mysqldump --all-databases --single-transaction > all_databases.sql

This backup acquires a global read lock on all tables (using *Note
`FLUSH TABLES WITH READ LOCK': flush.) at the beginning of the dump. As
soon as this lock has been acquired, the binary log coordinates are
read and the lock is released. If long updating statements are running
when the *Note `FLUSH': flush. statement is issued, the MySQL server
may get stalled until those statements finish. After that, the dump
becomes lock free and does not disturb reads and writes on the tables.
If the update statements that the MySQL server receives are short (in
terms of execution time), the initial lock period should not be
noticeable, even with many updates.

For point-in-time recovery (also known as `roll-forward,' when you need
to restore an old backup and replay the changes that happened since
that backup), it is often useful to rotate the binary log (see *Note
binary-log::) or at least know the binary log coordinates to which the
dump corresponds:

shell> mysqldump --all-databases --master-data=2 > all_databases.sql

Or:

shell> mysqldump --all-databases --flush-logs --master-data=2
> all_databases.sql

The `--master-data' and `--single-transaction' options can be used
simultaneously, which provides a convenient way to make an online
backup suitable for use prior to point-in-time recovery if tables are
stored using the `InnoDB' storage engine.

For more information on making backups, see *Note backup-methods::, and
*Note backup-strategy-example::.

If you encounter problems backing up views, please read the section
that covers restrictions on views which describes a workaround for
backing up views when this fails due to insufficient privileges. See
*Note view-restrictions::.

File: manual.info, Node: mysqlimport, Next: mysqlshow, Prev: mysqldump, Up: programs-client

5.5.5 `mysqlimport' -- A Data Import Program
--------------------------------------------

The *Note `mysqlimport': mysqlimport. client provides a command-line
interface to the *Note `LOAD DATA INFILE': load-data. SQL statement.
Most options to *Note `mysqlimport': mysqlimport. correspond directly
to clauses of *Note `LOAD DATA INFILE': load-data. syntax. See *Note
load-data::.

Invoke *Note `mysqlimport': mysqlimport. like this:

shell> mysqlimport [OPTIONS] DB_NAME TEXTFILE1 [TEXTFILE2 ...]

For each text file named on the command line, *Note `mysqlimport':
mysqlimport. strips any extension from the file name and uses the
result to determine the name of the table into which to import the
file's contents. For example, files named `patient.txt',
`patient.text', and `patient' all would be imported into a table named
`patient'.

*Note `mysqlimport': mysqlimport. supports the following options, which
can be specified on the command line or in the `[mysqlimport]' and
`[client]' option file groups. *Note `mysqlimport': mysqlimport. also
supports the options for processing option files described at *Note
option-file-options::.

*`mysqlimport' Options*

Format Option File Description IntroductionDeprecatedRemoved
-columns=column_listcolumns This option takes a
comma-separated list of
column names as its value
-compress compress Compress all information
sent between the client and
the server
-debug[=debug_options]debug Write a debugging log
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-delete delete Empty the table before
importing the text file
-fields-enclosed-by=stringfields-enclosed-byThis option has the same
meaning as the corresponding
clause for LOAD DATA INFILE
-fields-escaped-byfields-escaped-byThis option has the same
meaning as the corresponding
clause for LOAD DATA INFILE
-fields-optionally-enclosed-by=stringfields-optionally-enclosed-byThis option has the same
meaning as the corresponding
clause for LOAD DATA INFILE
-fields-terminated-by=stringfields-terminated-by- This option has the same
meaning as the corresponding
clause for LOAD DATA INFILE
-force force Continue even if an SQL
error occurs
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-ignore ignore See the description for the
-replace option
-ignore-lines=#ignore-linesIgnore the first N lines of
the data file
-lines-terminated-by=stringlines-terminated-byThis option has the same
meaning as the corresponding
clause for LOAD DATA INFILE
-local local Read input files locally
from the client host
-lock-tableslock-tables Lock all tables for writing
before processing any text
files
-low-prioritylow-priorityUse LOW_PRIORITY when
loading the table.
-password[=password]password The password to use when
connecting to the server
-pipe On Windows, connect to
server using a named pipe
-port=port_numport The TCP/IP port number to
use for the connection
-protocol=typeprotocol The connection protocol to
use
-replace replace The -replace and -ignore
options control handling of
input rows that duplicate
existing rows on unique key
values
-silent silent Produce output only when
errors occur
-socket=pathsocket For connections to localhost
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-user=user_name,user The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit

* `--help', `-?'

Display a help message and exit.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--columns=COLUMN_LIST', `-c COLUMN_LIST'

This option takes a comma-separated list of column names as its
value. The order of the column names indicates how to match data
file columns with table columns.

* `--compress', `-C'

Compress all information sent between the client and the server if
both support compression.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is `'d:t:o''.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set. See *Note
charset-configuration::.

* `--delete', `-D'

Empty the table before importing the text file.

* `--fields-terminated-by=...',

`--fields-enclosed-by=...',

`--fields-optionally-enclosed-by=...',

`--fields-escaped-by=...'

These options have the same meaning as the corresponding clauses
for *Note `LOAD DATA INFILE': load-data. See *Note load-data::.

* `--force', `-f'

Ignore errors. For example, if a table for a text file does not
exist, continue processing any remaining files. Without `--force',
*Note `mysqlimport': mysqlimport. exits if a table does not exist.

* `--host=HOST_NAME', `-h HOST_NAME'

Import data to the MySQL server on the given host. The default
host is `localhost'.

* `--ignore', `-i'

See the description for the `--replace' option.

* `--ignore-lines=N'

Ignore the first N lines of the data file.

* `--lines-terminated-by=...'

This option has the same meaning as the corresponding clause for
*Note `LOAD DATA INFILE': load-data. For example, to import
Windows files that have lines terminated with carriage
return/linefeed pairs, use `--lines-terminated-by="\r\n"'. (You
might have to double the backslashes, depending on the escaping
conventions of your command interpreter.) See *Note load-data::.

* `--local', `-L'

Read input files locally from the client host.

* `--lock-tables', `-l'

Lock _all_ tables for writing before processing any text files.
This ensures that all tables are synchronized on the server.

* `--low-priority'

Use `LOW_PRIORITY' when loading the table. This affects only
storage engines that use only table-level locking (such as
`MyISAM', `MEMORY', and `MERGE').

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--replace', `-r'

The `--replace' and `--ignore' options control handling of input
rows that duplicate existing rows on unique key values. If you
specify `--replace', new rows replace existing rows that have the
same unique key value. If you specify `--ignore', input rows that
duplicate an existing row on a unique key value are skipped. If
you do not specify either option, an error occurs when a duplicate
key value is found, and the rest of the text file is ignored.

* `--silent', `-s'

Silent mode. Produce output only when errors occur.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.

* `--version', `-V'

Display version information and exit.

Here is a sample session that demonstrates use of *Note `mysqlimport':
mysqlimport.:

shell> mysql -e 'CREATE TABLE imptest(id INT, n VARCHAR(30))' test
shell> ed
a
100 Max Sydow
101 Count Dracula
.
w imptest.txt
32
q
shell> od -c imptest.txt
0000000 1 0 0 \t M a x S y d o w \n 1 0
0000020 1 \t C o u n t D r a c u l a \n
0000040
shell> mysqlimport --local test imptest.txt
test.imptest: Records: 2 Deleted: 0 Skipped: 0 Warnings: 0
shell> mysql -e 'SELECT * FROM imptest' test
+------+---------------+
| id | n |
+------+---------------+
| 100 | Max Sydow |
| 101 | Count Dracula |
+------+---------------+

File: manual.info, Node: mysqlshow, Prev: mysqlimport, Up: programs-client

5.5.6 `mysqlshow' -- Display Database, Table, and Column Information
--------------------------------------------------------------------

The *Note `mysqlshow': mysqlshow. client can be used to quickly see
which databases exist, their tables, or a table's columns or indexes.

*Note `mysqlshow': mysqlshow. provides a command-line interface to
several SQL *Note `SHOW': show. statements. See *Note show::. The same
information can be obtained by using those statements directly. For
example, you can issue them from the *Note `mysql': mysql. client
program.

Invoke *Note `mysqlshow': mysqlshow. like this:

shell> mysqlshow [OPTIONS] [DB_NAME [TBL_NAME [COL_NAME]]]

* If no database is given, a list of database names is shown.

* If no table is given, all matching tables in the database are
shown.

* If no column is given, all matching columns and column types in
the table are shown.

The output displays only the names of those databases, tables, or
columns for which you have some privileges.

If the last argument contains shell or SQL wildcard characters (``*'',
``?'', ``%'', or ``_''), only those names that are matched by the
wildcard are shown. If a database name contains any underscores, those
should be escaped with a backslash (some Unix shells require two) to
get a list of the proper tables or columns. ``*'' and ``?'' characters
are converted into SQL ``%'' and ``_'' wildcard characters. This might
cause some confusion when you try to display the columns for a table
with a ``_'' in the name, because in this case, *Note `mysqlshow':
mysqlshow. shows you only the table names that match the pattern. This
is easily fixed by adding an extra ``%'' last on the command line as a
separate argument.

*Note `mysqlshow': mysqlshow. supports the following options, which can
be specified on the command line or in the `[mysqlshow]' and `[client]'
option file groups. *Note `mysqlshow': mysqlshow. also supports the
options for processing option files described at *Note
option-file-options::.

*`mysqlshow' Options*

Format Option File Description IntroductionDeprecatedRemoved
-compress compress Compress all information
sent between the client and
the server
-count count Show the number of rows per 5.0.6
table
-debug[=debug_options]debug Write a debugging log
-default-character-set=charset_namedefault-character-setUse charset_name as the
default character set
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-keys keys Show table indexes
-password[=password]password The password to use when
connecting to the server
-pipe On Windows, connect to
server using a named pipe
-port=port_numport The TCP/IP port number to
use for the connection
-protocol=typeprotocol The connection protocol to
use
-show-table-type Show a column indicating the 5.0.4
table type
-socket=pathsocket For connections to localhost
-ssl-ca=file_namessl-ca The path to a file that
contains a list of trusted
SSL CAs
-ssl-capath=directory_namessl-capath The path to a directory that
contains trusted SSL CA
certificates in PEM format
-ssl-cert=file_namessl-cert The name of the SSL
certificate file to use for
establishing a secure
connection
-ssl-cipher=cipher_listssl-cipher A list of allowable ciphers
to use for SSL encryption
-ssl-key=file_namessl-key The name of the SSL key file
to use for establishing a
secure connection
-ssl-verify-server-certssl-verify-server-certThe server's Common Name
value in its certificate is
verified against the host
name used when connecting to
the server
-status status Display extra information
about each table
-user=user_name,user The MySQL user name to use
when connecting to the server
-verbose Verbose mode
-version Display version information
and exit

* `--help', `-?'

Display a help message and exit.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--compress', `-C'

Compress all information sent between the client and the server if
both support compression.

* `--count'

Show the number of rows per table. This can be slow for
non-`MyISAM' tables. This option was added in MySQL 5.0.6.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is `'d:t:o''.

* `--default-character-set=CHARSET_NAME'

Use CHARSET_NAME as the default character set. See *Note
charset-configuration::.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--keys', `-k'

Show table indexes.

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line. You
can use an option file to avoid giving the password on the command
line.

* `--pipe', `-W'

On Windows, connect to the server using a named pipe. This option
applies only if the server supports named-pipe connections.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--show-table-type', `-t'

Show a column indicating the table type, as in `SHOW FULL TABLES'.
The type is `BASE TABLE' or `VIEW'. This option was added in MySQL
5.0.4.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--ssl*'

Options that begin with `--ssl' specify whether to connect to the
server using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--status', `-i'

Display extra information about each table.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.
This option can be used multiple times to increase the amount of
information.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: programs-admin-utils, Next: programs-development, Prev: programs-client, Up: programs

5.6 MySQL Administrative and Utility Programs
=============================================

* Menu:

* innochecksum:: `innochecksum' --- Offline InnoDB File Checksum Utility
* myisam-ftdump:: `myisam_ftdump' --- Display Full-Text Index information
* myisamchk:: `myisamchk' --- MyISAM Table-Maintenance Utility
* myisamlog:: `myisamlog' --- Display MyISAM Log File Contents
* myisampack:: `myisampack' --- Generate Compressed, Read-Only MyISAM Tables
* mysqlaccess:: `mysqlaccess' --- Client for Checking Access Privileges
* mysqlbinlog:: `mysqlbinlog' --- Utility for Processing Binary Log Files
* mysqldumpslow:: `mysqldumpslow' --- Summarize Slow Query Log Files
* mysqlhotcopy:: `mysqlhotcopy' --- A Database Backup Program
* instance-manager:: `mysqlmanager' --- The MySQL Instance Manager
* mysql-convert-table-format:: `mysql_convert_table_format' --- Convert Tables to Use a Given Storage Engine
* mysql-explain-log:: `mysql_explain_log' --- Use EXPLAIN on Statements in Query Log
* mysql-find-rows:: `mysql_find_rows' --- Extract SQL Statements from Files
* mysql-fix-extensions:: `mysql_fix_extensions' --- Normalize Table File Name Extensions
* mysql-setpermission:: `mysql_setpermission' --- Interactively Set Permissions in Grant Tables
* mysql-tableinfo:: `mysql_tableinfo' --- Generate Database Metadata
* mysql-waitpid:: `mysql_waitpid' --- Kill Process and Wait for Its Termination
* mysql-zap:: `mysql_zap' --- Kill Processes That Match a Pattern

This section describes administrative programs and programs that
perform miscellaneous utility operations.

File: manual.info, Node: innochecksum, Next: myisam-ftdump, Prev: programs-admin-utils, Up: programs-admin-utils

5.6.1 `innochecksum' -- Offline InnoDB File Checksum Utility
------------------------------------------------------------

*Note `innochecksum': innochecksum. prints checksums for `InnoDB'
files. This tool reads an `InnoDB' tablespace file, calculates the
checksum for each page, compares the calculated checksum to the stored
checksum, and reports mismatches, which indicate damaged pages. It was
originally developed to speed up verifying the integrity of tablespace
files after power outages but can also be used after file copies.
Because checksum mismatches will cause `InnoDB' to deliberately shut
down a running server, it can be preferable to use this tool rather
than waiting for a server in production usage to encounter the damaged
pages.

*Note `innochecksum': innochecksum. cannot be used on tablespace files
that the server already has open. For such files, you should use *Note
`CHECK TABLE': check-table. to check tables within the tablespace.

If checksum mismatches are found, you would normally restore the
tablespace from backup or start the server and attempt to use *Note
`mysqldump': mysqldump. to make a backup of the tables within the
tablespace.

Invoke *Note `innochecksum': innochecksum. like this:

shell> innochecksum [OPTIONS] FILE_NAME

*Note `innochecksum': innochecksum. supports the following options.
For options that refer to page numbers, the numbers are zero-based.

* `-c'

Print a count of the number of pages in the file.

* `-d'

Debug mode; prints checksums for each page.

* `-e NUM'

End at this page number.

* `-p NUM'

Check only this page number.

* `-s NUM'

Start at this page number.

* `-v'

Verbose mode; print a progress indicator every five seconds.

File: manual.info, Node: myisam-ftdump, Next: myisamchk, Prev: innochecksum, Up: programs-admin-utils

5.6.2 `myisam_ftdump' -- Display Full-Text Index information
------------------------------------------------------------

*Note `myisam_ftdump': myisam-ftdump. displays information about
`FULLTEXT' indexes in `MyISAM' tables. It reads the `MyISAM' index file
directly, so it must be run on the server host where the table is
located. Before using *Note `myisam_ftdump': myisam-ftdump, be sure to
issue a `FLUSH TABLES' statement first if the server is running.

*Note `myisam_ftdump': myisam-ftdump. scans and dumps the entire index,
which is not particularly fast. On the other hand, the distribution of
words changes infrequently, so it need not be run often.

Invoke *Note `myisam_ftdump': myisam-ftdump. like this:

shell> myisam_ftdump [OPTIONS] TBL_NAME INDEX_NUM

The TBL_NAME argument should be the name of a `MyISAM' table. You can
also specify a table by naming its index file (the file with the `.MYI'
suffix). If you do not invoke *Note `myisam_ftdump': myisam-ftdump. in
the directory where the table files are located, the table or index
file name must be preceded by the path name to the table's database
directory. Index numbers begin with 0.

Example: Suppose that the `test' database contains a table named
`mytexttablel' that has the following definition:

CREATE TABLE mytexttable
(
id INT NOT NULL,
txt TEXT NOT NULL,
PRIMARY KEY (id),
FULLTEXT (txt)
) ENGINE=MyISAM;

The index on `id' is index 0 and the `FULLTEXT' index on `txt' is index
1. If your working directory is the `test' database directory, invoke
*Note `myisam_ftdump': myisam-ftdump. as follows:

shell> myisam_ftdump mytexttable 1

If the path name to the `test' database directory is
`/usr/local/mysql/data/test', you can also specify the table name
argument using that path name. This is useful if you do not invoke
*Note `myisam_ftdump': myisam-ftdump. in the database directory:

shell> myisam_ftdump /usr/local/mysql/data/test/mytexttable 1

You can use *Note `myisam_ftdump': myisam-ftdump. to generate a list of
index entries in order of frequency of occurrence like this:

shell> myisam_ftdump -c mytexttable 1 | sort -r

*Note `myisam_ftdump': myisam-ftdump. supports the following options:

* `--help', `-h' `-?'

Display a help message and exit.

* `--count', `-c'

Calculate per-word statistics (counts and global weights).

* `--dump', `-d'

Dump the index, including data offsets and word weights.

* `--length', `-l'

Report the length distribution.

* `--stats', `-s'

Report global index statistics. This is the default operation if
no other operation is specified.

* `--verbose', `-v'

Verbose mode. Print more output about what the program does.

File: manual.info, Node: myisamchk, Next: myisamlog, Prev: myisam-ftdump, Up: programs-admin-utils

5.6.3 `myisamchk' -- MyISAM Table-Maintenance Utility
-----------------------------------------------------

* Menu:

* myisamchk-general-options:: `myisamchk' General Options
* myisamchk-check-options:: `myisamchk' Check Options
* myisamchk-repair-options:: `myisamchk' Repair Options
* myisamchk-other-options:: Other `myisamchk' Options
* myisamchk-table-info:: Obtaining Table Information with `myisamchk'
* myisamchk-memory:: `myisamchk' Memory Usage

The *Note `myisamchk': myisamchk. utility gets information about your
database tables or checks, repairs, or optimizes them. *Note
`myisamchk': myisamchk. works with `MyISAM' tables (tables that have
`.MYD' and `.MYI' files for storing data and indexes).

You can also use the *Note `CHECK TABLE': check-table. and *Note
`REPAIR TABLE': repair-table. statements to check and repair `MyISAM'
tables. See *Note check-table::, and *Note repair-table::.

*Caution*:

Invoke *Note `myisamchk': myisamchk. like this:

shell> myisamchk [OPTIONS] TBL_NAME ...

The OPTIONS specify what you want *Note `myisamchk': myisamchk. to do.
They are described in the following sections. You can also get a list
of options by invoking *Note `myisamchk --help': myisamchk.

With no options, *Note `myisamchk': myisamchk. simply checks your table
as the default operation. To get more information or to tell *Note
`myisamchk': myisamchk. to take corrective action, specify options as
described in the following discussion.

TBL_NAME is the database table you want to check or repair. If you run
*Note `myisamchk': myisamchk. somewhere other than in the database
directory, you must specify the path to the database directory, because
*Note `myisamchk': myisamchk. has no idea where the database is
located. In fact, *Note `myisamchk': myisamchk. does not actually care
whether the files you are working on are located in a database
directory. You can copy the files that correspond to a database table
into some other location and perform recovery operations on them there.

You can name several tables on the *Note `myisamchk': myisamchk.
command line if you wish. You can also specify a table by naming its
index file (the file with the `.MYI' suffix). This enables you to
specify all tables in a directory by using the pattern `*.MYI'. For
example, if you are in a database directory, you can check all the
`MyISAM' tables in that directory like this:

shell> myisamchk *.MYI

If you are not in the database directory, you can check all the tables
there by specifying the path to the directory:

shell> myisamchk /PATH/TO/DATABASE_DIR/*.MYI

You can even check all tables in all databases by specifying a wildcard
with the path to the MySQL data directory:

shell> myisamchk /PATH/TO/DATADIR/*/*.MYI

The recommended way to quickly check all `MyISAM' tables is:

shell> myisamchk --silent --fast /PATH/TO/DATADIR/*/*.MYI

If you want to check all `MyISAM' tables and repair any that are
corrupted, you can use the following command:

shell> myisamchk --silent --force --fast --update-state \
--key_buffer_size=64M --sort_buffer_size=64M \
--read_buffer_size=1M --write_buffer_size=1M \
/PATH/TO/DATADIR/*/*.MYI

This command assumes that you have more than 64MB free. For more
information about memory allocation with *Note `myisamchk': myisamchk,
see *Note myisamchk-memory::.

For additional information about using *Note `myisamchk': myisamchk, see
*Note myisam-table-maintenance::.

*Important*:

_You must ensure that no other program is using the tables while you
are running *Note `myisamchk': myisamchk._. The most effective means of
doing so is to shut down the MySQL server while running *Note
`myisamchk': myisamchk, or to lock all tables that *Note `myisamchk':
myisamchk. is being used on.

Otherwise, when you run *Note `myisamchk': myisamchk, it may display
the following error message:

warning: clients are using or haven't closed the table properly

This means that you are trying to check a table that has been updated
by another program (such as the *Note `mysqld': mysqld. server) that
hasn't yet closed the file or that has died without closing the file
properly, which can sometimes lead to the corruption of one or more
`MyISAM' tables.

If *Note `mysqld': mysqld. is running, you must force it to flush any
table modifications that are still buffered in memory by using *Note
`FLUSH TABLES': flush. You should then ensure that no one is using the
tables while you are running *Note `myisamchk': myisamchk.

However, the easiest way to avoid this problem is to use *Note `CHECK
TABLE': check-table. instead of *Note `myisamchk': myisamchk. to check
tables. See *Note check-table::.

*Note `myisamchk': myisamchk. supports the following options, which can
be specified on the command line or in the `[myisamchk]' option file
group. *Note `myisamchk': myisamchk. also supports the options for
processing option files described at *Note option-file-options::.

*`myisamchk' Options*

Format Option File Description IntroductionDeprecatedRemoved
-analyze analyze Analyze the distribution of
key values
-backup backup Make a backup of the .MYD
file as file_name-time.BAK
-block-search=offsetblock-searchFind the record that a block
at the given offset belongs
to
-check check Check the table for errors
-check-only-changedcheck-only-changedCheck only tables that have
changed since the last check
-correct-checksumcorrect-checksumCorrect the checksum
information for the table
-data-file-length=lendata-file-lengthMaximum length of the data
file (when re-creating data
file when it is full)
-debug[=debug_options]debug Write a debugging log
decode_bits=#decode_bits Decode_bits
-descriptiondescription Print some descriptive
information about the table
-extend-checkextend-checkDo a repair that tries to
recover every possible row
from the data file
-extended-checkextended-checkCheck the table very
thoroughly
-fast fast Check only tables that
haven't been closed properly
-force force Do a repair operation
automatically if myisamchk
finds any errors in the
table
-force force-recoverOverwrite old temporary
files. For use with the -r
or -o option
ft_max_word_len=#ft_max_word_lenMaximum word length for
FULLTEXT indexes
ft_min_word_len=#ft_min_word_lenMinimum word length for
FULLTEXT indexes
ft_stopword_file=valueft_stopword_fileUse stopwords from this file
instead of built-in list
-HELP Display help message and exit
-help Display help message and exit
-informationinformation Print informational
statistics about the table
that is checked
key_buffer_size=#key_buffer_sizeThe size of the buffer used
for index blocks for MyISAM
tables
-keys-used=valkeys-used A bit-value that indicates
which indexes to update
-max-record-length=lenmax-record-lengthSkip rows larger than the
given length if myisamchk
cannot allocate memory to
hold them
-medium-checkmedium-checkDo a check that is faster
than an -extend-check
operation
myisam_block_size=#myisam_block_sizeBlock size to be used for
MyISAM index pages
-parallel-recoverparallel-recoverUses the same technique as
-r and -n, but creates all
the keys in parallel, using
different threads (beta)
-quick quick Achieve a faster repair by
not modifying the data file.
read_buffer_size=#read_buffer_sizeEach thread that does a
sequential scan allocates a
buffer of this size for
each table it scans
-read-only read-only Don't mark the table as
checked
-recover recover Do a repair that can fix
almost any problem except
unique keys that aren't
unique
-safe-recoversafe-recoverDo a repair using an old
recovery method that reads
through all rows in order
and updates all index trees
based on the rows found
-set-auto-increment[=value]set-auto-incrementForce AUTO_INCREMENT
numbering for new records to
start at the given value
-set-character-set=nameset-character-setChange the character set
used by the table indexes
-set-collation=nameset-collationSpecify the collation to use
for sorting table indexes
-silent silent Silent mode
sort_buffer_size=#sort_buffer_sizeThe buffer that is allocated
when sorting the index when
doing a REPAIR or when
creating indexes with CREATE
INDEX or ALTER TABLE
-sort-index sort-index Sort the index tree blocks
in high-low order
sort_key_blocks=#sort_key_blockssort_key_blocks
-sort-records=#sort-recordsSort records according to a
particular index
-sort-recoversort-recoverForce myisamchk to use
sorting to resolve the keys
even if the temporary files
would be very large
stats_method=valuestats_methodSpecifies how MyISAM index
statistics collection code
should treat NULLs
-tmpdir=pathtmpdir Path of the directory to be
used for storing temporary
files
-unpack unpack Unpack a table that was
packed with myisampack
-update-stateupdate-stateStore information in the
.MYI file to indicate when
the table was checked and
whether the table crashed
-verbose Verbose mode
-version Display version information
and exit
write_buffer_size=#write_buffer_sizeWrite buffer size

File: manual.info, Node: myisamchk-general-options, Next: myisamchk-check-options, Prev: myisamchk, Up: myisamchk

5.6.3.1 `myisamchk' General Options
...................................

The options described in this section can be used for any type of table
maintenance operation performed by *Note `myisamchk': myisamchk. The
sections following this one describe options that pertain only to
specific operations, such as table checking or repairing.

* `--help', `-?'

Display a help message and exit. Options are grouped by type of
operation.

* `--HELP', `-H'

Display a help message and exit. Options are presented in a single
list.

* `--debug=DEBUG_OPTIONS', `-# DEBUG_OPTIONS'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is
`'d:t:o,/tmp/myisamchk.trace''.

* `--silent', `-s'

Silent mode. Write output only when errors occur. You can use `-s'
twice (`-ss') to make *Note `myisamchk': myisamchk. very silent.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.
This can be used with `-d' and `-e'. Use `-v' multiple times
(`-vv', `-vvv') for even more output.

* `--version', `-V'

Display version information and exit.

* `--wait', `-w'

Instead of terminating with an error if the table is locked, wait
until the table is unlocked before continuing. If you are running
*Note `mysqld': mysqld. with external locking disabled, the table
can be locked only by another *Note `myisamchk': myisamchk.
command.

You can also set the following variables by using `--VAR_NAME=VALUE'
syntax:

Variable Default Value
`decode_bits' 9
`ft_max_word_len' version-dependent
`ft_min_word_len' 4
`ft_stopword_file' built-in list
`key_buffer_size' 523264
`myisam_block_size' 1024
`read_buffer_size' 262136
`sort_buffer_size' 2097144
`sort_key_blocks' 16
`stats_method' nulls_unequal
`write_buffer_size' 262136

It is also possible to set variables by using
`--set-variable=VAR_NAME=VALUE' or `-O VAR_NAME=VALUE' syntax. However,
this syntax is deprecated as of MySQL 4.0.

The possible *Note `myisamchk': myisamchk. variables and their default
values can be examined with *Note `myisamchk --help': myisamchk.:

`sort_buffer_size' is used when the keys are repaired by sorting keys,
which is the normal case when you use `--recover'.

`key_buffer_size' is used when you are checking the table with
`--extend-check' or when the keys are repaired by inserting keys row by
row into the table (like when doing normal inserts). Repairing through
the key buffer is used in the following cases:

* You use `--safe-recover'.

* The temporary files needed to sort the keys would be more than
twice as big as when creating the key file directly. This is
often the case when you have large key values for *Note `CHAR':
char, *Note `VARCHAR': char, or *Note `TEXT': blob. columns,
because the sort operation needs to store the complete key values
as it proceeds. If you have lots of temporary space and you can
force *Note `myisamchk': myisamchk. to repair by sorting, you can
use the `--sort-recover' option.

Repairing through the key buffer takes much less disk space than using
sorting, but is also much slower.

If you want a faster repair, set the `key_buffer_size' and
`sort_buffer_size' variables to about 25% of your available memory. You
can set both variables to large values, because only one of them is
used at a time.

`myisam_block_size' is the size used for index blocks.

`stats_method' influences how `NULL' values are treated for index
statistics collection when the `--analyze' option is given. It acts
like the `myisam_stats_method' system variable. For more information,
see the description of `myisam_stats_method' in *Note
server-system-variables::, and *Note myisam-index-statistics::. For
MySQL 5.0, `stats_method' was added in MySQL 5.0.14. For older
versions, the statistics collection method is equivalent to
`nulls_equal'.

`ft_min_word_len' and `ft_max_word_len' indicate the minimum and
maximum word length for `FULLTEXT' indexes. `ft_stopword_file' names
the stopword file. These need to be set under the following
circumstances.

If you use *Note `myisamchk': myisamchk. to perform an operation that
modifies table indexes (such as repair or analyze), the `FULLTEXT'
indexes are rebuilt using the default full-text parameter values for
minimum and maximum word length and the stopword file unless you
specify otherwise. This can result in queries failing.

The problem occurs because these parameters are known only by the
server. They are not stored in `MyISAM' index files. To avoid the
problem if you have modified the minimum or maximum word length or the
stopword file in the server, specify the same `ft_min_word_len',
`ft_max_word_len', and `ft_stopword_file' values to *Note `myisamchk':
myisamchk. that you use for *Note `mysqld': mysqld. For example, if you
have set the minimum word length to 3, you can repair a table with
*Note `myisamchk': myisamchk. like this:

shell> myisamchk --recover --ft_min_word_len=3 TBL_NAME.MYI

To ensure that *Note `myisamchk': myisamchk. and the server use the
same values for full-text parameters, you can place each one in both
the `[mysqld]' and `[myisamchk]' sections of an option file:

[mysqld]
ft_min_word_len=3

[myisamchk]
ft_min_word_len=3

An alternative to using *Note `myisamchk': myisamchk. is to use the
*Note `REPAIR TABLE': repair-table, *Note `ANALYZE TABLE':
analyze-table, *Note `OPTIMIZE TABLE': optimize-table, or *Note `ALTER
TABLE': alter-table. These statements are performed by the server,
which knows the proper full-text parameter values to use.

File: manual.info, Node: myisamchk-check-options, Next: myisamchk-repair-options, Prev: myisamchk-general-options, Up: myisamchk

5.6.3.2 `myisamchk' Check Options
.................................

*Note `myisamchk': myisamchk. supports the following options for table
checking operations:

* `--check', `-c'

Check the table for errors. This is the default operation if you
specify no option that selects an operation type explicitly.

* `--check-only-changed', `-C'

Check only tables that have changed since the last check.

* `--extend-check', `-e'

Check the table very thoroughly. This is quite slow if the table
has many indexes. This option should only be used in extreme
cases. Normally, *Note `myisamchk': myisamchk. or *Note `myisamchk
--medium-check': myisamchk. should be able to determine whether
there are any errors in the table.

If you are using `--extend-check' and have plenty of memory,
setting the `key_buffer_size' variable to a large value helps the
repair operation run faster.

For a description of the output format, see *Note
myisamchk-table-info::.

* `--fast', `-F'

Check only tables that haven't been closed properly.

* `--force', `-f'

Do a repair operation automatically if *Note `myisamchk':
myisamchk. finds any errors in the table. The repair type is the
same as that specified with the `--recover' or `-r' option.

* `--information', `-i'

Print informational statistics about the table that is checked.

* `--medium-check', `-m'

Do a check that is faster than an `--extend-check' operation.
This finds only 99.99% of all errors, which should be good enough
in most cases.

* `--read-only', `-T'

Do not mark the table as checked. This is useful if you use *Note
`myisamchk': myisamchk. to check a table that is in use by some
other application that does not use locking, such as *Note
`mysqld': mysqld. when run with external locking disabled.

* `--update-state', `-U'

Store information in the `.MYI' file to indicate when the table
was checked and whether the table crashed. This should be used to
get full benefit of the `--check-only-changed' option, but you
shouldn't use this option if the *Note `mysqld': mysqld. server is
using the table and you are running it with external locking
disabled.

File: manual.info, Node: myisamchk-repair-options, Next: myisamchk-other-options, Prev: myisamchk-check-options, Up: myisamchk

5.6.3.3 `myisamchk' Repair Options
..................................

*Note `myisamchk': myisamchk. supports the following options for table
repair operations (operations performed when an option such as
`--recover' or `--safe-recover' is given):

* `--backup', `-B'

Make a backup of the `.MYD' file as `FILE_NAME-TIME.BAK'

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--correct-checksum'

Correct the checksum information for the table.

* `--data-file-length=LEN', `-D LEN'

The maximum length of the data file (when re-creating data file
when it is `full').

* `--extend-check', `-e'

Do a repair that tries to recover every possible row from the data
file. Normally, this also finds a lot of garbage rows. Do not use
this option unless you are desperate.

For a description of the output format, see *Note
myisamchk-table-info::.

* `--force', `-f'

Overwrite old intermediate files (files with names like
`TBL_NAME.TMD') instead of aborting.

* `--keys-used=VAL', `-k VAL'

For *Note `myisamchk': myisamchk, the option value is a bit-value
that indicates which indexes to update. Each binary bit of the
option value corresponds to a table index, where the first index
is bit 0. An option value of 0 disables updates to all indexes,
which can be used to get faster inserts. Deactivated indexes can
be reactivated by using *Note `myisamchk -r': myisamchk.

* `--no-symlinks', `-l'

Do not follow symbolic links. Normally *Note `myisamchk':
myisamchk. repairs the table that a symlink points to. This option
does not exist as of MySQL 4.0 because versions from 4.0 on do not
remove symlinks during repair operations.

* `--max-record-length=LEN'

Skip rows larger than the given length if *Note `myisamchk':
myisamchk. cannot allocate memory to hold them.

* `--parallel-recover', `-p'

Use the same technique as `-r' and `-n', but create all the keys
in parallel, using different threads. _This is beta-quality code.
Use at your own risk!_

* `--quick', `-q'

Achieve a faster repair by modifying only the index file, not the
data file. You can specify this option twice to force *Note
`myisamchk': myisamchk. to modify the original data file in case
of duplicate keys.

* `--recover', `-r'

Do a repair that can fix almost any problem except unique keys
that are not unique (which is an extremely unlikely error with
`MyISAM' tables). If you want to recover a table, this is the
option to try first. You should try `--safe-recover' only if *Note
`myisamchk': myisamchk. reports that the table cannot be recovered
using `--recover'. (In the unlikely case that `--recover' fails,
the data file remains intact.)

If you have lots of memory, you should increase the value of
`sort_buffer_size'.

* `--safe-recover', `-o'

Do a repair using an old recovery method that reads through all
rows in order and updates all index trees based on the rows found.
This is an order of magnitude slower than `--recover', but can
handle a couple of very unlikely cases that `--recover' cannot.
This recovery method also uses much less disk space than
`--recover'. Normally, you should repair first using `--recover',
and then with `--safe-recover' only if `--recover' fails.

If you have lots of memory, you should increase the value of
`key_buffer_size'.

* `--set-character-set=NAME'

Change the character set used by the table indexes. This option
was replaced by `--set-collation' in MySQL 5.0.3.

* `--set-collation=NAME'

Specify the collation to use for sorting table indexes. The
character set name is implied by the first part of the collation
name. This option was added in MySQL 5.0.3.

* `--sort-recover', `-n'

Force *Note `myisamchk': myisamchk. to use sorting to resolve the
keys even if the temporary files would be very large.

* `--tmpdir=PATH', `-t PATH'

The path of the directory to be used for storing temporary files.
If this is not set, *Note `myisamchk': myisamchk. uses the value
of the `TMPDIR' environment variable. `--tmpdir' can be set to a
list of directory paths that are used successively in round-robin
fashion for creating temporary files. The separator character
between directory names is the colon (``:'') on Unix and the
semicolon (``;'') on Windows, NetWare, and OS/2.

* `--unpack', `-u'

Unpack a table that was packed with *Note `myisampack': myisampack.

File: manual.info, Node: myisamchk-other-options, Next: myisamchk-table-info, Prev: myisamchk-repair-options, Up: myisamchk

5.6.3.4 Other `myisamchk' Options
.................................

*Note `myisamchk': myisamchk. supports the following options for
actions other than table checks and repairs:

* `--analyze', `-a'

Analyze the distribution of key values. This improves join
performance by enabling the join optimizer to better choose the
order in which to join the tables and which indexes it should use.
To obtain information about the key distribution, use a *Note
`myisamchk --description --verbose TBL_NAME': myisamchk. command
or the `SHOW INDEX FROM TBL_NAME' statement.

* `--block-search=OFFSET', `-b OFFSET'

Find the record that a block at the given offset belongs to.

* `--description', `-d'

Print some descriptive information about the table. Specifying
the `--verbose' option once or twice produces additional
information. See *Note myisamchk-table-info::.

* `--set-auto-increment[=VALUE]', `-A[VALUE]'

Force `AUTO_INCREMENT' numbering for new records to start at the
given value (or higher, if there are existing records with
`AUTO_INCREMENT' values this large). If VALUE is not specified,
`AUTO_INCREMENT' numbers for new records begin with the largest
value currently in the table, plus one.

* `--sort-index', `-S'

Sort the index tree blocks in high-low order. This optimizes seeks
and makes table scans that use indexes faster.

* `--sort-records=N', `-R N'

Sort records according to a particular index. This makes your data
much more localized and may speed up range-based *Note `SELECT':
select. and `ORDER BY' operations that use this index. (The first
time you use this option to sort a table, it may be very slow.)
To determine a table's index numbers, use *Note `SHOW INDEX':
show-index, which displays a table's indexes in the same order that
*Note `myisamchk': myisamchk. sees them. Indexes are numbered
beginning with 1.

If keys are not packed (`PACK_KEYS=0'), they have the same length,
so when *Note `myisamchk': myisamchk. sorts and moves records, it
just overwrites record offsets in the index. If keys are packed
(`PACK_KEYS=1'), *Note `myisamchk': myisamchk. must unpack key
blocks first, then re-create indexes and pack the key blocks
again. (In this case, re-creating indexes is faster than updating
offsets for each index.)

File: manual.info, Node: myisamchk-table-info, Next: myisamchk-memory, Prev: myisamchk-other-options, Up: myisamchk

5.6.3.5 Obtaining Table Information with `myisamchk'
....................................................

To obtain a description of a `MyISAM' table or statistics about it, use
the commands shown here. The output from these commands is explained
later in this section.

* *Note `myisamchk -d TBL_NAME': myisamchk.

Runs *Note `myisamchk': myisamchk. in `describe mode' to produce a
description of your table. If you start the MySQL server with
external locking disabled, *Note `myisamchk': myisamchk. may
report an error for a table that is updated while it runs.
However, because *Note `myisamchk': myisamchk. does not change the
table in describe mode, there is no risk of destroying data.

* *Note `myisamchk -dv TBL_NAME': myisamchk.

Adding `-v' runs *Note `myisamchk': myisamchk. in verbose mode so
that it produces more information about the table. Adding `-v' a
second time produces even more information.

* *Note `myisamchk -eis TBL_NAME': myisamchk.

Shows only the most important information from a table. This
operation is slow because it must read the entire table.

* *Note `myisamchk -eiv TBL_NAME': myisamchk.

This is like `-eis', but tells you what is being done.

The TBL_NAME argument can be either the name of a `MyISAM' table or the
name of its index file, as described in *Note myisamchk::. Multiple
TBL_NAME arguments can be given.

Suppose that a table named `person' has the following structure. (The
`MAX_ROWS' table option is included so that in the example output from
*Note `myisamchk': myisamchk. shown later, some values are smaller and
fit the output format more easily.)

CREATE TABLE person
(
id INT NOT NULL AUTO_INCREMENT,
last_name VARCHAR(20) NOT NULL,
first_name VARCHAR(20) NOT NULL,
birth DATE,
death DATE,
PRIMARY KEY (id),
INDEX (last_name, first_name),
INDEX (birth)
) MAX_ROWS = 1000000;

Suppose also that the table has these data and index file sizes:

-rw-rw---- 1 mysql mysql 9347072 Aug 19 11:47 person.MYD
-rw-rw---- 1 mysql mysql 6066176 Aug 19 11:47 person.MYI

Example of *Note `myisamchk -dvv': myisamchk. output:

MyISAM file: person
Record format: Packed
Character set: latin1_swedish_ci (8)
File-version: 1
Creation time: 2009-08-19 16:47:41
Recover time: 2009-08-19 16:47:56
Status: checked,analyzed,optimized keys
Auto increment key: 1 Last value: 306688
Data records: 306688 Deleted blocks: 0
Datafile parts: 306688 Deleted data: 0
Datafile pointer (bytes): 4 Keyfile pointer (bytes): 3
Datafile length: 9347072 Keyfile length: 6066176
Max datafile length: 4294967294 Max keyfile length: 17179868159
Recordlength: 54

table description:
Key Start Len Index Type Rec/key Root Blocksize
1 2 4 unique long 1 99328 1024
2 6 20 multip. varchar prefix 512 3563520 1024
27 20 varchar 512
3 48 3 multip. uint24 NULL 306688 6065152 1024

Field Start Length Nullpos Nullbit Type
1 1 1
2 2 4 no zeros
3 6 21 varchar
4 27 21 varchar
5 48 3 1 1 no zeros
6 51 3 1 2 no zeros

Explanations for the types of information *Note `myisamchk': myisamchk.
produces are given here. `Keyfile' refers to the index file. `Record'
and `row' are synonymous, as are `field' and `column.'

The initial part of the table description contains these values:

* `MyISAM file'

Name of the `MyISAM' (index) file.

* `Record format'

The format used to store table rows. The preceding examples use
`Fixed length'. Other possible values are `Compressed' and
`Packed'. (`Packed' corresponds to what `SHOW TABLE STATUS'
reports as `Dynamic'.)

* `Chararacter set'

The table default character set.

* `File-version'

Version of `MyISAM' format. Currently always 1.

* `Creation time'

When the data file was created.

* `Recover time'

When the index/data file was last reconstructed.

* `Status'

Table status flags. Possible values are `crashed', `open',
`changed', `analyzed', `optimized keys', and `sorted index pages'.

* `Auto increment key', `Last value'

The key number associated the table's `AUTO_INCREMENT' column, and
the most recently generated value for this column. These fields do
not appear if there is no such column.

* `Data records'

The number of rows in the table.

* `Deleted blocks'

How many deleted blocks still have reserved space. You can
optimize your table to minimize this space. See *Note
myisam-optimization::.

* `Datafile parts'

For dynamic-row format, this indicates how many data blocks there
are. For an optimized table without fragmented rows, this is the
same as `Data records'.

* `Deleted data'

How many bytes of unreclaimed deleted data there are. You can
optimize your table to minimize this space. See *Note
myisam-optimization::.

* `Datafile pointer'

The size of the data file pointer, in bytes. It is usually 2, 3,
4, or 5 bytes. Most tables manage with 2 bytes, but this cannot be
controlled from MySQL yet. For fixed tables, this is a row
address. For dynamic tables, this is a byte address.

* `Keyfile pointer'

The size of the index file pointer, in bytes. It is usually 1, 2,
or 3 bytes. Most tables manage with 2 bytes, but this is
calculated automatically by MySQL. It is always a block address.

* `Max datafile length'

How long the table data file can become, in bytes.

* `Max keyfile length'

How long the table index file can become, in bytes.

* `Recordlength'

How much space each row takes, in bytes.

The `table description' part of the output includes a list of all keys
in the table. For each key, *Note `myisamchk': myisamchk. displays some
low-level information:

* `Key'

This key's number. This value is shown only for the first column
of the key. If this value is missing, the line corresponds to the
second or later column of a multiple-column key. For the table
shown in the example, there are two `table description' lines for
the second index. This indicates that it is a multiple-part index
with two parts.

* `Start'

Where in the row this portion of the index starts.

* `Len'

How long this portion of the index is. For packed numbers, this
should always be the full length of the column. For strings, it
may be shorter than the full length of the indexed column, because
you can index a prefix of a string column. The total length of a
multiple-part key is the sum of the `Len' values for all key parts.

* `Index'

Whether a key value can exist multiple times in the index.
Possible values are `unique' or `multip.' (multiple).

* `Type'

What data type this portion of the index has. This is a `MyISAM'
data type with the possible values `packed', `stripped', or
`empty'.

* `Root'

Address of the root index block.

* `Blocksize'

The size of each index block. By default this is 1024, but the
value may be changed at compile time when MySQL is built from
source.

* `Rec/key'

This is a statistical value used by the optimizer. It tells how
many rows there are per value for this index. A unique index
always has a value of 1. This may be updated after a table is
loaded (or greatly changed) with *Note `myisamchk -a': myisamchk.
If this is not updated at all, a default value of 30 is given.

The last part of the output provides information about each column:

* `Field'

The column number.

* `Start'

The byte position of the column within table rows.

* `Length'

The length of the column in bytes.

* `Nullpos', `Nullbit'

For columns that can be `NULL', `MyISAM' stores `NULL' values as a
flag in a byte. Depending on how many nullable columns there are,
there can be one or more bytes used for this purpose. The
`Nullpos' and `Nullbit' values, if nonempty, indicate which byte
and bit contains that flag indicating whether the column is `NULL'.

The position and number of bytes used to store `NULL' flags is
shown in the line for field 1. This is why there are six `Field'
lines for the `person' table even though it has only five columns.

* `Type'

The data type. The value may contain any of the following
descriptors:

* `constant'

All rows have the same value.

* `no endspace'

Do not store endspace.

* `no endspace, not_always'

Do not store endspace and do not do endspace compression for
all values.

* `no endspace, no empty'

Do not store endspace. Do not store empty values.

* `table-lookup'

The column was converted to an *Note `ENUM': enum.

* `zerofill(N)'

The most significant N bytes in the value are always 0 and
are not stored.

* `no zeros'

Do not store zeros.

* `always zero'

Zero values are stored using one bit.

* `Huff tree'

The number of the Huffman tree associated with the column.

* `Bits'

The number of bits used in the Huffman tree.

The `Huff tree' and `Bits' fields are displayed if the table has been
compressed with *Note `myisampack': myisampack. See *Note myisampack::,
for an example of this information.

Example of *Note `myisamchk -eiv': myisamchk. output:

Checking MyISAM file: person
Data records: 306688 Deleted blocks: 0
- check file-size
- check record delete-chain
No recordlinks
- check key delete-chain
block_size 1024:
- check index reference
- check data record references index: 1
Key: 1: Keyblocks used: 98% Packed: 0% Max levels: 3
- check data record references index: 2
Key: 2: Keyblocks used: 99% Packed: 97% Max levels: 3
- check data record references index: 3
Key: 3: Keyblocks used: 98% Packed: -14% Max levels: 3
Total: Keyblocks used: 98% Packed: 89%

- check records and index references
*** LOTS OF ROW NUMBERS DELETED ***

Records: 306688 M.recordlength: 25 Packed: 83%
Recordspace used: 97% Empty space: 2% Blocks/Record: 1.00
Record blocks: 306688 Delete blocks: 0
Record data: 7934464 Deleted data: 0
Lost space: 256512 Linkdata: 1156096

User time 43.08, System time 1.68
Maximum resident set size 0, Integral resident set size 0
Non-physical pagefaults 0, Physical pagefaults 0, Swaps 0
Blocks in 0 out 7, Messages in 0 out 0, Signals 0
Voluntary context switches 0, Involuntary context switches 0
Maximum memory usage: 1046926 bytes (1023k)

*Note `myisamchk -eiv': myisamchk. output includes the following
information:

* `Data records'

The number of rows in the table.

* `Deleted blocks'

How many deleted blocks still have reserved space. You can
optimize your table to minimize this space. See *Note
myisam-optimization::.

* `Key'

The key number.

* `Keyblocks used'

What percentage of the keyblocks are used. When a table has just
been reorganized with *Note `myisamchk': myisamchk, the values are
very high (very near theoretical maximum).

* `Packed'

MySQL tries to pack key values that have a common suffix. This
can only be used for indexes on *Note `CHAR': char. and *Note
`VARCHAR': char. columns. For long indexed strings that have
similar leftmost parts, this can significantly reduce the space
used. In the preceding example, the second key is 40 bytes long
and a 97% reduction in space is achieved.

* `Max levels'

How deep the B-tree for this key is. Large tables with long key
values get high values.

* `Records'

How many rows are in the table.

* `M.recordlength'

The average row length. This is the exact row length for tables
with fixed-length rows, because all rows have the same length.

* `Packed'

MySQL strips spaces from the end of strings. The `Packed' value
indicates the percentage of savings achieved by doing this.

* `Recordspace used'

What percentage of the data file is used.

* `Empty space'

What percentage of the data file is unused.

* `Blocks/Record'

Average number of blocks per row (that is, how many links a
fragmented row is composed of). This is always 1.0 for
fixed-format tables. This value should stay as close to 1.0 as
possible. If it gets too large, you can reorganize the table. See
*Note myisam-optimization::.

* `Recordblocks'

How many blocks (links) are used. For fixed-format tables, this is
the same as the number of rows.

* `Deleteblocks'

How many blocks (links) are deleted.

* `Recorddata'

How many bytes in the data file are used.

* `Deleted data'

How many bytes in the data file are deleted (unused).

* `Lost space'

If a row is updated to a shorter length, some space is lost. This
is the sum of all such losses, in bytes.

* `Linkdata'

When the dynamic table format is used, row fragments are linked
with pointers (4 to 7 bytes each). `Linkdata' is the sum of the
amount of storage used by all such pointers.

File: manual.info, Node: myisamchk-memory, Prev: myisamchk-table-info, Up: myisamchk

5.6.3.6 `myisamchk' Memory Usage
................................

Memory allocation is important when you run *Note `myisamchk':
myisamchk. *Note `myisamchk': myisamchk. uses no more memory than its
memory-related variables are set to. If you are going to use *Note
`myisamchk': myisamchk. on very large tables, you should first decide
how much memory you want it to use. The default is to use only about
3MB to perform repairs. By using larger values, you can get *Note
`myisamchk': myisamchk. to operate faster. For example, if you have
more than 512MB RAM available, you could use options such as these (in
addition to any other options you might specify):

shell> myisamchk --sort_buffer_size=256M \
--key_buffer_size=512M \
--read_buffer_size=64M \
--write_buffer_size=64M ...

Using `--sort_buffer_size=16M' is probably enough for most cases.

Be aware that *Note `myisamchk': myisamchk. uses temporary files in
`TMPDIR'. If `TMPDIR' points to a memory file system, out of memory
errors can easily occur. If this happens, run *Note `myisamchk':
myisamchk. with the `--tmpdir=PATH' option to specify a directory
located on a file system that has more space.

When performing repair operations, *Note `myisamchk': myisamchk. also
needs a lot of disk space:

* Twice the size of the data file (the original file and a copy).
This space is not needed if you do a repair with `--quick'; in
this case, only the index file is re-created. _This space must be
available on the same file system as the original data file_, as
the copy is created in the same directory as the original.

* Space for the new index file that replaces the old one. The old
index file is truncated at the start of the repair operation, so
you usually ignore this space. This space must be available on the
same file system as the original data file.

* When using `--recover' or `--sort-recover' (but not when using
`--safe-recover'), you need space on disk for sorting. This space
is allocated in the temporary directory (specified by `TMPDIR' or
`--tmpdir=PATH'). The following formula yields the amount of
space required:

(LARGEST_KEY + ROW_POINTER_LENGTH) * NUMBER_OF_ROWS * 2

You can check the length of the keys and the ROW_POINTER_LENGTH
with *Note `myisamchk -dv TBL_NAME': myisamchk. (see *Note
myisamchk-table-info::). The ROW_POINTER_LENGTH and NUMBER_OF_ROWS
values are the `Datafile pointer' and `Data records' values in the
table description. To determine the LARGEST_KEY value, check the
`Key' lines in the table description. The `Len' column indicates
the number of bytes for each key part. For a multiple-column
index, the key size is the sum of the `Len' values for all key
parts.

If you have a problem with disk space during repair, you can try
`--safe-recover' instead of `--recover'.

File: manual.info, Node: myisamlog, Next: myisampack, Prev: myisamchk, Up: programs-admin-utils

5.6.4 `myisamlog' -- Display MyISAM Log File Contents
-----------------------------------------------------

*Note `myisamlog': myisamlog. processes the contents of a `MyISAM' log
file.

Invoke *Note `myisamlog': myisamlog. like this:

shell> myisamlog [OPTIONS] [LOG_FILE [TBL_NAME] ...]
shell> isamlog [OPTIONS] [LOG_FILE [TBL_NAME] ...]

The default operation is update (`-u'). If a recovery is done (`-r'),
all writes and possibly updates and deletes are done and errors are
only counted. The default log file name is `myisam.log' for *Note
`myisamlog': myisamlog. and `isam.log' for `isamlog' if no LOG_FILE
argument is given. If tables are named on the command line, only those
tables are updated.

*Note `myisamlog': myisamlog. supports the following options:

* `-?', `-I'

Display a help message and exit.

* `-c N'

Execute only N commands.

* `-f N'

Specify the maximum number of open files.

* `-i'

Display extra information before exiting.

* `-o OFFSET'

Specify the starting offset.

* `-p N'

Remove N components from path.

* `-r'

Perform a recovery operation.

* `-R RECORD_POS_FILE RECORD_POS'

Specify record position file and record position.

* `-u'

Perform an update operation.

* `-v'

Verbose mode. Print more output about what the program does. This
option can be given multiple times to produce more and more output.

* `-w WRITE_FILE'

Specify the write file.

* `-V'

Display version information.

File: manual.info, Node: myisampack, Next: mysqlaccess, Prev: myisamlog, Up: programs-admin-utils

5.6.5 `myisampack' -- Generate Compressed, Read-Only MyISAM Tables
------------------------------------------------------------------

The *Note `myisampack': myisampack. utility compresses `MyISAM' tables.
*Note `myisampack': myisampack. works by compressing each column in
the table separately. Usually, *Note `myisampack': myisampack. packs
the data file 40% to 70%.

When the table is used later, the server reads into memory the
information needed to decompress columns. This results in much better
performance when accessing individual rows, because you only have to
uncompress exactly one row.

MySQL uses `mmap()' when possible to perform memory mapping on
compressed tables. If `mmap()' does not work, MySQL falls back to
normal read/write file operations.

Please note the following:

* If the *Note `mysqld': mysqld. server was invoked with external
locking disabled, it is not a good idea to invoke *Note
`myisampack': myisampack. if the table might be updated by the
server during the packing process. It is safest to compress tables
with the server stopped.

* After packing a table, it becomes read only. This is generally
intended (such as when accessing packed tables on a CD).

Invoke *Note `myisampack': myisampack. like this:

shell> myisampack [OPTIONS] FILE_NAME ...

Each file name argument should be the name of an index (`.MYI') file.
If you are not in the database directory, you should specify the path
name to the file. It is permissible to omit the `.MYI' extension.

After you compress a table with *Note `myisampack': myisampack, you
should use *Note `myisamchk -rq': myisamchk. to rebuild its indexes.
*Note myisamchk::.

*Note `myisampack': myisampack. supports the following options. It also
reads option files and supports the options for processing them
described at *Note option-file-options::.

* `--help', `-?'

Display a help message and exit.

* `--backup', `-b'

Make a backup of each table's data file using the name
`TBL_NAME.OLD'.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is `'d:t:o''.

* `--force', `-f'

Produce a packed table even if it becomes larger than the original
or if the intermediate file from an earlier invocation of *Note
`myisampack': myisampack. exists. (*Note `myisampack':
myisampack. creates an intermediate file named `TBL_NAME.TMD' in
the database directory while it compresses the table. If you kill
*Note `myisampack': myisampack, the `.TMD' file might not be
deleted.) Normally, *Note `myisampack': myisampack. exits with an
error if it finds that `TBL_NAME.TMD' exists. With `--force',
*Note `myisampack': myisampack. packs the table anyway.

* `--join=BIG_TBL_NAME', `-j BIG_TBL_NAME'

Join all tables named on the command line into a single packed
table BIG_TBL_NAME. All tables that are to be combined _must_ have
identical structure (same column names and types, same indexes,
and so forth).

BIG_TBL_NAME must not exist prior to the join operation. All
source tables named on the command line to be merged into
BIG_TBL_NAME must exist. The source tables are read for the join
operation but not modified. The join operation does not create a
`.frm' file for BIG_TBL_NAME, so after the join operation
finishes, copy the `.frm' file from one of the source tables and
name it `BIG_TBL_NAME.frm'.

* `--silent', `-s'

Silent mode. Write output only when errors occur.

* `--test', `-t'

Do not actually pack the table, just test packing it.

* `--tmpdir=PATH', `-T PATH'

Use the named directory as the location where *Note `myisampack':
myisampack. creates temporary files.

* `--verbose', `-v'

Verbose mode. Write information about the progress of the packing
operation and its result.

* `--version', `-V'

Display version information and exit.

* `--wait', `-w'

Wait and retry if the table is in use. If the *Note `mysqld':
mysqld. server was invoked with external locking disabled, it is
not a good idea to invoke *Note `myisampack': myisampack. if the
table might be updated by the server during the packing process.

The following sequence of commands illustrates a typical table
compression session:

shell> ls -l station.*
-rw-rw-r-- 1 monty my 994128 Apr 17 19:00 station.MYD
-rw-rw-r-- 1 monty my 53248 Apr 17 19:00 station.MYI
-rw-rw-r-- 1 monty my 5767 Apr 17 19:00 station.frm

shell> myisamchk -dvv station

MyISAM file: station
Isam-version: 2
Creation time: 1996-03-13 10:08:58
Recover time: 1997-02-02 3:06:43
Data records: 1192 Deleted blocks: 0
Datafile parts: 1192 Deleted data: 0
Datafile pointer (bytes): 2 Keyfile pointer (bytes): 2
Max datafile length: 54657023 Max keyfile length: 33554431
Recordlength: 834
Record format: Fixed length

table description:
Key Start Len Index Type Root Blocksize Rec/key
1 2 4 unique unsigned long 1024 1024 1
2 32 30 multip. text 10240 1024 1

Field Start Length Type
1 1 1
2 2 4
3 6 4
4 10 1
5 11 20
6 31 1
7 32 30
8 62 35
9 97 35
10 132 35
11 167 4
12 171 16
13 187 35
14 222 4
15 226 16
16 242 20
17 262 20
18 282 20
19 302 30
20 332 4
21 336 4
22 340 1
23 341 8
24 349 8
25 357 8
26 365 2
27 367 2
28 369 4
29 373 4
30 377 1
31 378 2
32 380 8
33 388 4
34 392 4
35 396 4
36 400 4
37 404 1
38 405 4
39 409 4
40 413 4
41 417 4
42 421 4
43 425 4
44 429 20
45 449 30
46 479 1
47 480 1
48 481 79
49 560 79
50 639 79
51 718 79
52 797 8
53 805 1
54 806 1
55 807 20
56 827 4
57 831 4

shell> myisampack station.MYI
Compressing station.MYI: (1192 records)
- Calculating statistics

normal: 20 empty-space: 16 empty-zero: 12 empty-fill: 11
pre-space: 0 end-space: 12 table-lookups: 5 zero: 7
Original trees: 57 After join: 17
- Compressing file
87.14%
Remember to run myisamchk -rq on compressed tables

shell> ls -l station.*
-rw-rw-r-- 1 monty my 127874 Apr 17 19:00 station.MYD
-rw-rw-r-- 1 monty my 55296 Apr 17 19:04 station.MYI
-rw-rw-r-- 1 monty my 5767 Apr 17 19:00 station.frm

shell> myisamchk -dvv station

MyISAM file: station
Isam-version: 2
Creation time: 1996-03-13 10:08:58
Recover time: 1997-04-17 19:04:26
Data records: 1192 Deleted blocks: 0
Datafile parts: 1192 Deleted data: 0
Datafile pointer (bytes): 3 Keyfile pointer (bytes): 1
Max datafile length: 16777215 Max keyfile length: 131071
Recordlength: 834
Record format: Compressed

table description:
Key Start Len Index Type Root Blocksize Rec/key
1 2 4 unique unsigned long 10240 1024 1
2 32 30 multip. text 54272 1024 1

Field Start Length Type Huff tree Bits
1 1 1 constant 1 0
2 2 4 zerofill(1) 2 9
3 6 4 no zeros, zerofill(1) 2 9
4 10 1 3 9
5 11 20 table-lookup 4 0
6 31 1 3 9
7 32 30 no endspace, not_always 5 9
8 62 35 no endspace, not_always, no empty 6 9
9 97 35 no empty 7 9
10 132 35 no endspace, not_always, no empty 6 9
11 167 4 zerofill(1) 2 9
12 171 16 no endspace, not_always, no empty 5 9
13 187 35 no endspace, not_always, no empty 6 9
14 222 4 zerofill(1) 2 9
15 226 16 no endspace, not_always, no empty 5 9
16 242 20 no endspace, not_always 8 9
17 262 20 no endspace, no empty 8 9
18 282 20 no endspace, no empty 5 9
19 302 30 no endspace, no empty 6 9
20 332 4 always zero 2 9
21 336 4 always zero 2 9
22 340 1 3 9
23 341 8 table-lookup 9 0
24 349 8 table-lookup 10 0
25 357 8 always zero 2 9
26 365 2 2 9
27 367 2 no zeros, zerofill(1) 2 9
28 369 4 no zeros, zerofill(1) 2 9
29 373 4 table-lookup 11 0
30 377 1 3 9
31 378 2 no zeros, zerofill(1) 2 9
32 380 8 no zeros 2 9
33 388 4 always zero 2 9
34 392 4 table-lookup 12 0
35 396 4 no zeros, zerofill(1) 13 9
36 400 4 no zeros, zerofill(1) 2 9
37 404 1 2 9
38 405 4 no zeros 2 9
39 409 4 always zero 2 9
40 413 4 no zeros 2 9
41 417 4 always zero 2 9
42 421 4 no zeros 2 9
43 425 4 always zero 2 9
44 429 20 no empty 3 9
45 449 30 no empty 3 9
46 479 1 14 4
47 480 1 14 4
48 481 79 no endspace, no empty 15 9
49 560 79 no empty 2 9
50 639 79 no empty 2 9
51 718 79 no endspace 16 9
52 797 8 no empty 2 9
53 805 1 17 1
54 806 1 3 9
55 807 20 no empty 3 9
56 827 4 no zeros, zerofill(2) 2 9
57 831 4 no zeros, zerofill(1) 2 9

*Note `myisampack': myisampack. displays the following kinds of
information:

* `normal'

The number of columns for which no extra packing is used.

* `empty-space'

The number of columns containing values that are only spaces.
These occupy one bit.

* `empty-zero'

The number of columns containing values that are only binary
zeros. These occupy one bit.

* `empty-fill'

The number of integer columns that do not occupy the full byte
range of their type. These are changed to a smaller type. For
example, a *Note `BIGINT': numeric-types. column (eight bytes)
can be stored as a *Note `TINYINT': numeric-types. column (one
byte) if all its values are in the range from `-128' to `127'.

* `pre-space'

The number of decimal columns that are stored with leading spaces.
In this case, each value contains a count for the number of
leading spaces.

* `end-space'

The number of columns that have a lot of trailing spaces. In this
case, each value contains a count for the number of trailing
spaces.

* `table-lookup'

The column had only a small number of different values, which were
converted to an *Note `ENUM': enum. before Huffman compression.

* `zero'

The number of columns for which all values are zero.

* `Original trees'

The initial number of Huffman trees.

* `After join'

The number of distinct Huffman trees left after joining trees to
save some header space.

After a table has been compressed, the `Field' lines displayed by *Note
`myisamchk -dvv': myisamchk. include additional information about each
column:

* `Type'

The data type. The value may contain any of the following
descriptors:

* `constant'

All rows have the same value.

* `no endspace'

Do not store endspace.

* `no endspace, not_always'

Do not store endspace and do not do endspace compression for
all values.

* `no endspace, no empty'

Do not store endspace. Do not store empty values.

* `table-lookup'

The column was converted to an *Note `ENUM': enum.

* `zerofill(N)'

The most significant N bytes in the value are always 0 and
are not stored.

* `no zeros'

Do not store zeros.

* `always zero'

Zero values are stored using one bit.

* `Huff tree'

The number of the Huffman tree associated with the column.

* `Bits'

The number of bits used in the Huffman tree.

After you run *Note `myisampack': myisampack, you must run *Note
`myisamchk': myisamchk. to re-create any indexes. At this time, you can
also sort the index blocks and create statistics needed for the MySQL
optimizer to work more efficiently:

shell> myisamchk -rq --sort-index --analyze TBL_NAME.MYI

After you have installed the packed table into the MySQL database
directory, you should execute *Note `mysqladmin flush-tables':
mysqladmin. to force *Note `mysqld': mysqld. to start using the new
table.

To unpack a packed table, use the `--unpack' option to *Note
`myisamchk': myisamchk.

File: manual.info, Node: mysqlaccess, Next: mysqlbinlog, Prev: myisampack, Up: programs-admin-utils

5.6.6 `mysqlaccess' -- Client for Checking Access Privileges
------------------------------------------------------------

*Note `mysqlaccess': mysqlaccess. is a diagnostic tool that Yves
Carlier has provided for the MySQL distribution. It checks the access
privileges for a host name, user name, and database combination. Note
that *Note `mysqlaccess': mysqlaccess. checks access using only the
`user', `db', and `host' tables. It does not check table, column, or
routine privileges specified in the `tables_priv', `columns_priv', or
`procs_priv' tables.

Invoke *Note `mysqlaccess': mysqlaccess. like this:

shell> mysqlaccess [HOST_NAME [USER_NAME [DB_NAME]]] [OPTIONS]

*Note `mysqlaccess': mysqlaccess. supports the following options.

*`mysqlaccess' Options*

Format Option File Description IntroductionDeprecatedRemoved
-brief brief Generate reports in
single-line tabular format
-commit commit Copy the new access
privileges from the
temporary tables to the
original grant tables
-copy copy Reload the temporary grant
tables from original ones
-db=db_name db Specify the database name
-debug=# debug Specify the debug level
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-howto howto Display some examples that
show how to use mysqlaccess
-old_server old_server Assume that the server is an
old MySQL server (prior to
MySQL 3.21)
-password[=password]password The password to use when
connecting to the server
-plan plan Display suggestions and
ideas for future releases
-preview preview Show the privilege
differences after making
changes to the temporary
grant tables
-relnotes relnotes Display the release notes
-rhost=host_namerhost Connect to the MySQL server
on the given host
-rollback rollback Undo the most recent changes
to the temporary grant
tables.
-spassword[=password]spassword The password to use when
connecting to the server as
the superuser
-superuser=user_namesuperuser Specify the user name for
connecting as the superuser
-table table Generate reports in table
format
-user=user_name,user The MySQL user name to use
when connecting
-version Display version information
and exit

* `--help', `-?'

Display a help message and exit.

* `--brief', `-b'

Generate reports in single-line tabular format.

* `--commit'

Copy the new access privileges from the temporary tables to the
original grant tables. The grant tables must be flushed for the
new privileges to take effect. (For example, execute a *Note
`mysqladmin reload': mysqladmin. command.)

* `--copy'

Reload the temporary grant tables from original ones.

* `--db=DB_NAME', `-d DB_NAME'

Specify the database name.

* `--debug=N'

Specify the debug level. N can be an integer from 0 to 3.

* `--host=HOST_NAME', `-h HOST_NAME'

The host name to use in the access privileges.

* `--howto'

Display some examples that show how to use *Note `mysqlaccess':
mysqlaccess.

* `--old_server'

Assume that the server is an old MySQL server (before MySQL 3.21)
that does not yet know how to handle full `WHERE' clauses.

* `--password[=PASSWORD]', `-p[PASSWORD]'

The password to use when connecting to the server. If you omit the
PASSWORD value following the `--password' or `-p' option on the
command line, *Note `mysqlaccess': mysqlaccess. prompts for one.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::.

* `--plan'

Display suggestions and ideas for future releases.

* `--preview'

Show the privilege differences after making changes to the
temporary grant tables.

* `--relnotes'

Display the release notes.

* `--rhost=HOST_NAME', `-H HOST_NAME'

Connect to the MySQL server on the given host.

* `--rollback'

Undo the most recent changes to the temporary grant tables.

* `--spassword[=PASSWORD]', `-P[PASSWORD]'

The password to use when connecting to the server as the
superuser. If you omit the PASSWORD value following the
`--spassword' or `-p' option on the command line, *Note
`mysqlaccess': mysqlaccess. prompts for one.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::.

* `--superuser=USER_NAME', `-U USER_NAME'

Specify the user name for connecting as the superuser.

* `--table', `-t'

Generate reports in table format.

* `--user=USER_NAME', `-u USER_NAME'

The user name to use in the access privileges.

* `--version', `-v'

Display version information and exit.

If your MySQL distribution is installed in some nonstandard location,
you must change the location where *Note `mysqlaccess': mysqlaccess.
expects to find the *Note `mysql': mysql. client. Edit the
`mysqlaccess' script at approximately line 18. Search for a line that
looks like this:

$MYSQL = '/usr/local/bin/mysql'; # path to mysql executable

File: manual.info, Node: mysqlbinlog, Next: mysqldumpslow, Prev: mysqlaccess, Up: programs-admin-utils

5.6.7 `mysqlbinlog' -- Utility for Processing Binary Log Files
--------------------------------------------------------------

The server's binary log consists of files containing `events' that
describe modifications to database contents. The server writes these
files in binary format. To display their contents in text format, use
the *Note `mysqlbinlog': mysqlbinlog. utility. You can also use *Note
`mysqlbinlog': mysqlbinlog. to display the contents of relay log files
written by a slave server in a replication setup because relay logs
have the same format as binary logs. The binary log and relay log are
discussed further in *Note binary-log::, and *Note slave-logs::.

Invoke *Note `mysqlbinlog': mysqlbinlog. like this:

shell> mysqlbinlog [OPTIONS] LOG_FILE ...

For example, to display the contents of the binary log file named
`binlog.000003', use this command:

shell> mysqlbinlog binlog.0000003

The output includes events contained in `binlog.000003'. Event
information includes the SQL statement, the ID of the server on which
it was executed, the timestamp when the statement was executed, how
much time it took, and so forth.

Events are preceded by header comments that provide additional
information. For example:

# at 141
#100309 9:28:36 server id 123 end_log_pos 245
Query thread_id=3350 exec_time=11 error_code=0

In the first line, the number following `at' indicates the starting
position of the event in the binary log file.

The second line starts with a date and time indicating when the
statement started on the server where the event originated. For
replication, this timestamp is propagated to slave servers. `server
id' is the `server_id' value of the server where the event originated.
`end_log_pos' indicates where the next event starts (that is, it is the
end position of the current event + 1). `thread_id' indicates which
thread executed the event. `exec_time' is the time spent executing the
event, on a master server. On a slave, it is the difference of the end
execution time on the slave minus the beginning execution time on the
master. The difference serves as an indicator of how much replication
lags behind the master. `error_code' indicates the result from
executing the event. Zero means that no error occurred.

The output from *Note `mysqlbinlog': mysqlbinlog. can be re-executed
(for example, by using it as input to *Note `mysql': mysql.) to redo
the statements in the log. This is useful for recovery operations
after a server crash. For other usage examples, see the discussion
later in this section and in *Note point-in-time-recovery::.

Normally, you use *Note `mysqlbinlog': mysqlbinlog. to read binary log
files directly and apply them to the local MySQL server. It is also
possible to read binary logs from a remote server by using the
`--read-from-remote-server' option. To read remote binary logs, the
connection parameter options can be given to indicate how to connect to
the server. These options are `--host', `--password', `--port',
`--protocol', `--socket', and `--user'; they are ignored except when
you also use the `--read-from-remote-server' option.

*Note `mysqlbinlog': mysqlbinlog. supports the following options, which
can be specified on the command line or in the `[mysqlbinlog]' and
`[client]' option file groups. *Note `mysqlbinlog': mysqlbinlog. also
supports the options for processing option files described at *Note
option-file-options::.

*`mysqlbinlog' Options*

Format Option File Description IntroductionDeprecatedRemoved
-character-sets-dir=pathcharacter-sets-dirThe directory where
character sets are installed
-database=db_namedatabase List entries for just this
database
-debug[=debug_options]debug Write a debugging log
-disable-log-bindisable-log-binDisable binary logging
-force-read force-read If mysqlbinlog reads a
binary log event that it
does not recognize, it
prints a warning
-help Display help message and exit
-hexdump hexdump Display a hex dump of the 5.0.16
log in comments
-host=host_namehost Connect to the MySQL server
on the given host
-local-load=pathlocal-load Prepare local temporary
files for LOAD DATA INFILE
in the specified directory
-offset=# offset Skip the first N entries in
the log
-password[=password]password The password to use when
connecting to the server
-port=port_numport The TCP/IP port number to
use for the connection
-position=# position Deprecated. Use
-start-position
-protocol=typeprotocol The connection protocol to
use
-read-from-remote-serverread-from-remote-serverRead the binary log from a
MySQL server rather than
reading a local log file
-result-file=nameresult-file Direct output to the given
file
-set-charset=charset_nameset-charset Add a SET NAMES charset_name 5.0.23
statement to the output
-short-form short-form Display only the statements
contained in the log
-socket=pathsocket For connections to localhost
-start-datetime=datetimestart-datetimeStart reading the binary log
at the first event having a
timestamp equal to or later
than the datetime argument
-start-position=#start-positionStart reading the binary log
at the first event having a
position equal to or
greater than the argument
-stop-datetime=datetimestop-datetimeStop reading the binary log
at the first event having a
timestamp equal to or
greater than the datetime
argument
-stop-position=#stop-positionStop reading the binary log
at the first event having a
position equal to or
greater than the argument
-to-last-logto-last-log Do not stop at the end of
the requested binary log
from a MySQL server, but
rather continue printing
until the end of the last
binary log
-user=user_name,user The MySQL user name to use
when connecting to the server
-version Display version information
and exit

* `--help', `-?'

Display a help message and exit.

* `--character-sets-dir=PATH'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--database=DB_NAME', `-d DB_NAME'

This option causes *Note `mysqlbinlog': mysqlbinlog. to output
entries from the binary log (local log only) that occur while
DB_NAME is been selected as the default database by *Note `USE':
use.

The `--database' option for *Note `mysqlbinlog': mysqlbinlog. is
similar to the `--binlog-do-db' option for *Note `mysqld': mysqld,
but can be used to specify only one database. If `--database' is
given multiple times, only the last instance is used.

The `--database' option works as follows:

* While DB_NAME is the default database, statements are output
whether they modify tables in DB_NAME or a different database.

* Unless DB_NAME is selected as the default database,
statements are not output, even if they modify tables in
DB_NAME.

* There is an exception for *Note `CREATE DATABASE':
create-database, *Note `ALTER DATABASE': alter-database, and
*Note `DROP DATABASE': drop-database. The database being
_created, altered, or dropped_ is considered to be the
default database when determining whether to output the
statement.

Suppose that the binary log contains these statements:

INSERT INTO test.t1 (i) VALUES(100);
INSERT INTO db2.t2 (j) VALUES(200);
USE test;
INSERT INTO test.t1 (i) VALUES(101);
INSERT INTO t1 (i) VALUES(102);
INSERT INTO db2.t2 (j) VALUES(201);
USE db2;
INSERT INTO test.t1 (i) VALUES(103);
INSERT INTO db2.t2 (j) VALUES(202);
INSERT INTO t2 (j) VALUES(203);

*Note `mysqlbinlog --database=test': mysqlbinlog. does not output
the first two *Note `INSERT': insert. statements because there is
no default database. It outputs the three *Note `INSERT': insert.
statements following *Note `USE test': use, but not the three
*Note `INSERT': insert. statements following *Note `USE db2': use.

*Note `mysqlbinlog --database=db2': mysqlbinlog. does not output
the first two *Note `INSERT': insert. statements because there is
no default database. It does not output the three *Note `INSERT':
insert. statements following *Note `USE test': use, but does
output the three *Note `INSERT': insert. statements following
*Note `USE db2': use.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is
`'d:t:o,/tmp/mysqlbinlog.trace''.

* `--disable-log-bin', `-D'

Disable binary logging. This is useful for avoiding an endless
loop if you use the `--to-last-log' option and are sending the
output to the same MySQL server. This option also is useful when
restoring after a crash to avoid duplication of the statements you
have logged.

This option requires that you have the `SUPER' privilege. It causes
*Note `mysqlbinlog': mysqlbinlog. to include a `SET sql_log_bin =
0' statement in its output to disable binary logging of the
remaining output. The *Note `SET': set-option. statement is
ineffective unless you have the `SUPER' privilege.

* `--force-read', `-f'

With this option, if *Note `mysqlbinlog': mysqlbinlog. reads a
binary log event that it does not recognize, it prints a warning,
ignores the event, and continues. Without this option, *Note
`mysqlbinlog': mysqlbinlog. stops if it reads such an event.

* `--hexdump', `-H'

Display a hex dump of the log in comments. The hex output can be
helpful for replication debugging. Hex dump format is discussed
later in this section. This option was added in MySQL 5.0.16.

* `--host=HOST_NAME', `-h HOST_NAME'

Get the binary log from the MySQL server on the given host.

* `--local-load=PATH', `-l PATH'

Prepare local temporary files for *Note `LOAD DATA INFILE':
load-data. in the specified directory.

*Important*:

These temporary files are not automatically removed by *Note
`mysqlbinlog': mysqlbinlog. or any other MySQL program.

* `--offset=N', `-o N'

Skip the first N entries in the log.

* `--password[=PASSWORD]', `-p[PASSWORD]'

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for connecting to a remote server.

* `--position=N'

Deprecated. Use `--start-position' instead. `--position' is
removed in MySQL 5.5.

* `--protocol={TCP|SOCKET|PIPE|MEMORY}'

* `--read-from-remote-server', `-R'

Read the binary log from a MySQL server rather than reading a
local log file. Any connection parameter options are ignored
unless this option is given as well. These options are `--host',
`--password', `--port', `--protocol', `--socket', and `--user'.

This option requires that the remote server be running. It works
only for binary log files on the remote server, not relay log
files.

* `--result-file=NAME', `-r NAME'

Direct output to the given file.

* `--set-charset=CHARSET_NAME'

Add a `SET NAMES CHARSET_NAME' statement to the output to specify
the character set to be used for processing log files. This option
was added in MySQL 5.0.23.

* `--short-form', `-s'

Display only the statements contained in the log, without any
extra information. This is for testing only, and should not be
used in production systems.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--start-datetime=DATETIME'

Start reading the binary log at the first event having a timestamp
equal to or later than the DATETIME argument. The DATETIME value
is relative to the local time zone on the machine where you run
*Note `mysqlbinlog': mysqlbinlog. The value should be in a format
accepted for the *Note `DATETIME': datetime. or *Note `TIMESTAMP':
datetime. data types. For example:

shell> mysqlbinlog --start-datetime="2005-12-25 11:25:56" binlog.000003

This option is useful for point-in-time recovery. See *Note
backup-strategy-example::.

* `--start-position=N', `-j N'

Start reading the binary log at the first event having a position
equal to or greater than N. This option applies to the first log
file named on the command line.

This option is useful for point-in-time recovery. See *Note
backup-strategy-example::.

* `--stop-datetime=DATETIME'

Stop reading the binary log at the first event having a timestamp
equal to or later than the DATETIME argument. This option is
useful for point-in-time recovery. See the description of the
`--start-datetime' option for information about the DATETIME value.

This option is useful for point-in-time recovery. See *Note
backup-strategy-example::.

* `--stop-position=N'

Stop reading the binary log at the first event having a position
equal to or greater than N. This option applies to the last log
file named on the command line.

This option is useful for point-in-time recovery. See *Note
backup-strategy-example::.

* `--to-last-log', `-t'

Do not stop at the end of the requested binary log from a MySQL
server, but rather continue printing until the end of the last
binary log. If you send the output to the same MySQL server, this
may lead to an endless loop. This option requires
`--read-from-remote-server'.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to a remote server.

* `--version', `-V'

Display version information and exit.

You can also set the following variable by using `--VAR_NAME=VALUE'
syntax:

* `open_files_limit'

Specify the number of open file descriptors to reserve.

It is also possible to set variables by using
`--set-variable=VAR_NAME=VALUE' or `-O VAR_NAME=VALUE' syntax. _This
syntax is deprecated_.

You can pipe the output of *Note `mysqlbinlog': mysqlbinlog. into the
*Note `mysql': mysql. client to execute the events contained in the
binary log. This technique is used to recover from a crash when you
have an old backup (see *Note point-in-time-recovery::). For example:

shell> mysqlbinlog binlog.000001 | mysql -u root -p

Or:

shell> mysqlbinlog binlog.[0-9]* | mysql -u root -p

You can also redirect the output of *Note `mysqlbinlog': mysqlbinlog.
to a text file instead, if you need to modify the statement log first
(for example, to remove statements that you do not want to execute for
some reason). After editing the file, execute the statements that it
contains by using it as input to the *Note `mysql': mysql. program:

shell> mysqlbinlog binlog.000001 > tmpfile
shell> ... EDIT TMPFILE ...
shell> mysql -u root -p < tmpfile

When *Note `mysqlbinlog': mysqlbinlog. is invoked with the
`--start-position' option, it displays only those events with an offset
in the binary log greater than or equal to a given position (the given
position must match the start of one event). It also has options to stop
and start when it sees an event with a given date and time. This
enables you to perform point-in-time recovery using the
`--stop-datetime' option (to be able to say, for example, `roll forward
my databases to how they were today at 10:30 a.m.').

If you have more than one binary log to execute on the MySQL server,
the safe method is to process them all using a single connection to the
server. Here is an example that demonstrates what may be _unsafe_:

shell> mysqlbinlog binlog.000001 | mysql -u root -p # DANGER!!
shell> mysqlbinlog binlog.000002 | mysql -u root -p # DANGER!!

Processing binary logs this way using multiple connections to the
server causes problems if the first log file contains a *Note `CREATE
TEMPORARY TABLE': create-table. statement and the second log contains a
statement that uses the temporary table. When the first *Note `mysql':
mysql. process terminates, the server drops the temporary table. When
the second *Note `mysql': mysql. process attempts to use the table,
the server reports `unknown table.'

To avoid problems like this, use a _single_ *Note `mysql': mysql.
process to execute the contents of all binary logs that you want to
process. Here is one way to do so:

shell> mysqlbinlog binlog.000001 binlog.000002 | mysql -u root -p

Another approach is to write all the logs to a single file and then
process the file:

shell> mysqlbinlog binlog.000001 > /tmp/statements.sql
shell> mysqlbinlog binlog.000002 >> /tmp/statements.sql
shell> mysql -u root -p -e "source /tmp/statements.sql"

*Note `mysqlbinlog': mysqlbinlog. can produce output that reproduces a
*Note `LOAD DATA INFILE': load-data. operation without the original
data file. *Note `mysqlbinlog': mysqlbinlog. copies the data to a
temporary file and writes a *Note `LOAD DATA LOCAL INFILE': load-data.
statement that refers to the file. The default location of the
directory where these files are written is system-specific. To specify
a directory explicitly, use the `--local-load' option.

Because *Note `mysqlbinlog': mysqlbinlog. converts *Note `LOAD DATA
INFILE': load-data. statements to *Note `LOAD DATA LOCAL INFILE':
load-data. statements (that is, it adds `LOCAL'), both the client and
the server that you use to process the statements must be configured
with the `LOCAL' capability enabled. See *Note load-data-local::.

*Warning*:

The temporary files created for *Note `LOAD DATA LOCAL': load-data.
statements are _not_ automatically deleted because they are needed
until you actually execute those statements. You should delete the
temporary files yourself after you no longer need the statement log.
The files can be found in the temporary file directory and have names
like ORIGINAL_FILE_NAME-#-#.

The `--hexdump' option produces a hex dump of the log contents:

shell> mysqlbinlog --hexdump master-bin.000001

The hex output consists of comment lines beginning with `#', so the
output might look like this for the preceding command:

/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
# at 4
#051024 17:24:13 server id 1 end_log_pos 98
# Position Timestamp Type Master ID Size Master Pos Flags
# 00000004 9d fc 5c 43 0f 01 00 00 00 5e 00 00 00 62 00 00 00 00 00
# 00000017 04 00 35 2e 30 2e 31 35 2d 64 65 62 75 67 2d 6c |..5.0.15.debug.l|
# 00000027 6f 67 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |og..............|
# 00000037 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
# 00000047 00 00 00 00 9d fc 5c 43 13 38 0d 00 08 00 12 00 |.......C.8......|
# 00000057 04 04 04 04 12 00 00 4b 00 04 1a |.......K...|
# Start: binlog v 4, server v 5.0.15-debug-log created 051024 17:24:13
# at startup
ROLLBACK;

Hex dump output currently contains the following elements. This format
is subject to change.

* `Position': The byte position within the log file.

* `Timestamp': The event timestamp. In the example shown, `'9d fc 5c
43'' is the representation of `'051024 17:24:13'' in hexadecimal.

* `Type': The event type code. In the example shown, `'0f''
indicates a `FORMAT_DESCRIPTION_EVENT'. The following table lists
the possible type codes.

Type Name Meaning
`00' `UNKNOWN_EVENT'This event should never be present in the log.
`01' `START_EVENT_V3'This indicates the start of a log file written by
MySQL 4 or earlier.
`02' `QUERY_EVENT' The most common type of events. These contain
statements executed on the master.
`03' `STOP_EVENT' Indicates that master has stopped.
`04' `ROTATE_EVENT'Written when the master switches to a new log
file.
`05' `INTVAR_EVENT'Used for `AUTO_INCREMENT' values or when the
`LAST_INSERT_ID()' function is used in the
statement.
`06' `LOAD_EVENT' Used for *Note `LOAD DATA INFILE': load-data. in
MySQL 3.23.
`07' `SLAVE_EVENT' Reserved for future use.
`08' `CREATE_FILE_EVENT'Used for *Note `LOAD DATA INFILE': load-data.
statements. This indicates the start of execution
of such a statement. A temporary file is created
on the slave. Used in MySQL 4 only.
`09' `APPEND_BLOCK_EVENT'Contains data for use in a *Note `LOAD DATA
INFILE': load-data. statement. The data is stored
in the temporary file on the slave.
`0a' `EXEC_LOAD_EVENT'Used for *Note `LOAD DATA INFILE': load-data.
statements. The contents of the temporary file is
stored in the table on the slave. Used in MySQL
4 only.
`0b' `DELETE_FILE_EVENT'Rollback of a *Note `LOAD DATA INFILE':
load-data. statement. The temporary file should
be deleted on the slave.
`0c' `NEW_LOAD_EVENT'Used for *Note `LOAD DATA INFILE': load-data. in
MySQL 4 and earlier.
`0d' `RAND_EVENT' Used to send information about random values if
the `RAND()' function is used in the statement.
`0e' `USER_VAR_EVENT'Used to replicate user variables.
`0f' `FORMAT_DESCRIPTION_EVENT'This indicates the start of a log file written by
MySQL 5 or later.
`10' `XID_EVENT' Event indicating commit of an XA transaction.
`11' `BEGIN_LOAD_QUERY_EVENT'Used for *Note `LOAD DATA INFILE': load-data.
statements in MySQL 5 and later.
`12' `EXECUTE_LOAD_QUERY_EVENT'Used for *Note `LOAD DATA INFILE': load-data.
statements in MySQL 5 and later.
`13' `TABLE_MAP_EVENT'Reserved for future use.
`14' `WRITE_ROWS_EVENT'Reserved for future use.
`15' `UPDATE_ROWS_EVENT'Reserved for future use.
`16' `DELETE_ROWS_EVENT'Reserved for future use.

* `Master ID': The server ID of the master that created the event.

* `Size': The size in bytes of the event.

* `Master Pos': The position of the next event in the original
master log file.

* `Flags': 16 flags. Currently, the following flags are used. The
others are reserved for future use.

Flag Name Meaning
`01' `LOG_EVENT_BINLOG_IN_USE_F'Log file correctly closed. (Used only in
`FORMAT_DESCRIPTION_EVENT'.) If this flag is set
(if the flags are, for example, `'01 00'') in a
`FORMAT_DESCRIPTION_EVENT', the log file has not
been properly closed. Most probably this is
because of a master crash (for example, due to
power failure).
`02' Reserved for future use.
`04' `LOG_EVENT_THREAD_SPECIFIC_F'Set if the event is dependent on the connection
it was executed in (for example, `'04 00''), for
example, if the event uses temporary tables.
`08' `LOG_EVENT_SUPPRESS_USE_F'Set in some circumstances when the event is not
dependent on the default database.

File: manual.info, Node: mysqldumpslow, Next: mysqlhotcopy, Prev: mysqlbinlog, Up: programs-admin-utils

5.6.8 `mysqldumpslow' -- Summarize Slow Query Log Files
-------------------------------------------------------

The MySQL slow query log contains information about queries that take a
long time to execute (see *Note slow-query-log::). *Note
`mysqldumpslow': mysqldumpslow. parses MySQL slow query log files and
prints a summary of their contents.

Normally, *Note `mysqldumpslow': mysqldumpslow. groups queries that are
similar except for the particular values of number and string data
values. It `abstracts' these values to `N' and `'S'' when displaying
summary output. The `-a' and `-n' options can be used to modify value
abstracting behavior.

Invoke *Note `mysqldumpslow': mysqldumpslow. like this:

shell> mysqldumpslow [OPTIONS] [LOG_FILE ...]

*Note `mysqldumpslow': mysqldumpslow. supports the following options.

*`mysqldumpslow' Options*

Format Option File Description IntroductionDeprecatedRemoved
-a Do not abstract all numbers
to N and strings to S
-n num Abstract numbers with at
least the specified digits
-debug debug Write debugging information
-g pattern Only consider statements
that match the pattern
-help Display help message and exit
-h name Host name of the server in
the log file name
-i name Name of the server instance
-l Do not subtract lock time
from total time
-r Reverse the sort order
-s value How to sort output
-t num Display only first num
queries
-verbose verbose Verbose mode

* `--help'

Display a help message and exit.

* `-a'

Do not abstract all numbers to `N' and strings to `'S''.

* `--debug', `-d'

Run in debug mode.

* `-g PATTERN'

Consider only queries that match the (`grep'-style) pattern.

* `-h HOST_NAME'

Host name of MySQL server for `*-slow.log' file name. The value can
contain a wildcard. The default is `*' (match all).

* `-i NAME'

Name of server instance (if using *Note `mysql.server':
mysql-server. startup script).

* `-l'

Do not subtract lock time from total time.

* `-n N'

Abstract numbers with at least N digits within names.

* `-r'

Reverse the sort order.

* `-s SORT_TYPE'

How to sort the output. The value of SORT_TYPE should be chosen
from the following list:

* `t', `at': Sort by query time or average query time

* `l', `al': Sort by lock time or average lock time

* `r', `ar': Sort by rows sent or average rows sent

* `c': Sort by count

By default, *Note `mysqldumpslow': mysqldumpslow. sorts by average
query time (equivalent to `-s at').

* `-t N'

Display only the first N queries in the output.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.

Example of usage:

shell> mysqldumpslow

Reading mysql slow query log from /usr/local/mysql/data/mysqld51-apple-slow.log
Count: 1 Time=4.32s (4s) Lock=0.00s (0s) Rows=0.0 (0), root[root]@localhost
insert into t2 select * from t1

Count: 3 Time=2.53s (7s) Lock=0.00s (0s) Rows=0.0 (0), root[root]@localhost
insert into t2 select * from t1 limit N

Count: 3 Time=2.13s (6s) Lock=0.00s (0s) Rows=0.0 (0), root[root]@localhost
insert into t1 select * from t1

File: manual.info, Node: mysqlhotcopy, Next: instance-manager, Prev: mysqldumpslow, Up: programs-admin-utils

5.6.9 `mysqlhotcopy' -- A Database Backup Program
-------------------------------------------------

*Note `mysqlhotcopy': mysqlhotcopy. is a Perl script that was
originally written and contributed by Tim Bunce. It uses *Note `FLUSH
TABLES': flush, *Note `LOCK TABLES': lock-tables, and `cp' or `scp' to
make a database backup. It is a fast way to make a backup of the
database or single tables, but it can be run only on the same machine
where the database directories are located. *Note `mysqlhotcopy':
mysqlhotcopy. works only for backing up `MyISAM' and `ARCHIVE' tables.
It runs on Unix and NetWare.

To use *Note `mysqlhotcopy': mysqlhotcopy, you must have read access to
the files for the tables that you are backing up, the `SELECT'
privilege for those tables, the `RELOAD' privilege (to be able to
execute *Note `FLUSH TABLES': flush.), and the `LOCK TABLES' privilege
(to be able to lock the tables).

shell> mysqlhotcopy DB_NAME [/PATH/TO/NEW_DIRECTORY]

shell> mysqlhotcopy DB_NAME_1 ... DB_NAME_N /PATH/TO/NEW_DIRECTORY

Back up tables in the given database that match a regular expression:

shell> mysqlhotcopy DB_NAME./REGEX/

The regular expression for the table name can be negated by prefixing
it with a tilde (``~''):

shell> mysqlhotcopy DB_NAME./~REGEX/

*Note `mysqlhotcopy': mysqlhotcopy. supports the following options,
which can be specified on the command line or in the `[mysqlhotcopy]'
and `[client]' option file groups.

*`mysqlhotcopy' Options*

Format Option File Description IntroductionDeprecatedRemoved
-addtodest addtodest Do not rename target
directory (if it exists);
merely add files to it
-allowold allowold Do not abort if a target
exists; rename it by adding
an _old suffix
-checkpoint=db_name.tbl_namecheckpoint Insert checkpoint entries
-chroot=pathchroot Base directory of the chroot
jail in which mysqld operates
-debug debug Write a debugging log
-dryrun dryrun Report actions without
performing them
-flushlog flushlog Flush logs after all tables
are locked
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-keepold keepold Do not delete previous
(renamed) target when done
-noindices noindices Do not include full index
files in the backup
-password[=password]password The password to use when
connecting to the server
-port=port_numport The TCP/IP port number to
use for the connection
-quiet quiet Be silent except for errors
-regexp regexp Copy all databases with
names that match the given
regular expression
-resetmasterresetmaster Reset the binary log after
locking all the tables
-resetslave resetslave Reset the master.info file
after locking all the tables
-socket=pathsocket For connections to localhost
-tmpdir=pathtmpdir The temporary directory
-user=user_name,user The MySQL user name to use
when connecting to the server

* `--help', `-?'

Display a help message and exit.

* `--addtodest'

Do not rename target directory (if it exists); merely add files to
it.

* `--allowold'

Do not abort if a target exists; rename it by adding an `_old'
suffix.

* `--checkpoint=DB_NAME.TBL_NAME'

Insert checkpoint entries into the specified database DB_NAME and
table TBL_NAME.

* `--chroot=PATH'

Base directory of the `chroot' jail in which *Note `mysqld':
mysqld. operates. The PATH value should match that of the
`--chroot' option given to *Note `mysqld': mysqld.

* `--debug'

Enable debug output.

* `--dryrun', `-n'

Report actions without performing them.

* `--flushlog'

Flush logs after all tables are locked.

* `--host=HOST_NAME', `-h HOST_NAME'

The host name of the local host to use for making a TCP/IP
connection to the local server. By default, the connection is made
to `localhost' using a Unix socket file.

* `--keepold'

Do not delete previous (renamed) target when done.

* `--method=COMMAND'

The method for copying files (`cp' or `scp'). The default is `cp'.

* `--noindices'

Do not include full index files for *Note `MyISAM':
myisam-storage-engine. tables in the backup. This makes the
backup smaller and faster. The indexes for reloaded tables can be
reconstructed later with *Note `myisamchk -rq': myisamchk.

* `--password=PASSWORD', `-pPASSWORD'

The password to use when connecting to the server. The password
value is not optional for this option, unlike for other MySQL
programs.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use when connecting to the local server.

* `--quiet', `-q'

Be silent except for errors.

* `--record_log_pos=DB_NAME.TBL_NAME'

Record master and slave status in the specified database DB_NAME
and table TBL_NAME.

* `--regexp=EXPR'

Copy all databases with names that match the given regular
expression.

* `--resetmaster'

Reset the binary log after locking all the tables.

* `--resetslave'

Reset the `master.info' file after locking all the tables.

* `--socket=PATH', `-S PATH'

The Unix socket file to use for connections to `localhost'.

* `--suffix=STR'

The suffix to use for names of copied databases.

* `--tmpdir=PATH'

The temporary directory. The default is `/tmp'.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

Use `perldoc' for additional *Note `mysqlhotcopy': mysqlhotcopy.
documentation, including information about the structure of the tables
needed for the `--checkpoint' and `--record_log_pos' options:

shell> perldoc mysqlhotcopy

File: manual.info, Node: instance-manager, Next: mysql-convert-table-format, Prev: mysqlhotcopy, Up: programs-admin-utils

5.6.10 `mysqlmanager' -- The MySQL Instance Manager
---------------------------------------------------

* Menu:

* instance-manager-command-options:: MySQL Instance Manager Command Options
* instance-manager-configuration-files:: MySQL Instance Manager Configuration Files
* instance-manager-startup-process:: Starting the MySQL Server with MySQL Instance Manager
* instance-manager-security-passwords:: Instance Manager User and Password Management
* instance-manager-security-monitoring:: MySQL Server Instance Status Monitoring
* instance-manager-security:: Connecting to MySQL Instance Manager
* instance-manager-commands:: MySQL Instance Manager Commands

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

`mysqlmanager' is the MySQL Instance Manager (IM). This program
monitors and manages MySQL Database Server instances. MySQL Instance
Manager is available for Unix-like operating systems, and also on
Windows as of MySQL 5.0.13. It runs as a daemon that listens on a
TCP/IP port. On Unix, it also listens on a Unix socket file.

MySQL Instance Manager is included in MySQL distributions from version
5.0.3, and can be used in place of the `mysqld_safe' script to start
and stop one or more instances of MySQL Server. Because Instance
Manager can manage multiple server instances, it can also be used in
place of the *Note `mysqld_multi': mysqld-multi. script. Instance
Manager offers these capabilities:

* Instance Manager can start and stop instances, and report on the
status of instances.

* Server instances can be treated as guarded or unguarded:

* When Instance Manager starts, it starts each guarded
instance. If the instance crashes, Instance Manager detects
this and restarts it. When Instance Manager stops, it stops
the instance.

* A nonguarded instance is not started when Instance Manager
starts or monitored by it. If the instance crashes after
being started, Instance Manager does not restart it. When
Instance Manager exits, it does not stop the instance if it
is running.

Instances are guarded by default. An instance can be designated as
nonguarded by including the `nonguarded' option in the
configuration file.

* Instance Manager provides an interactive interface for configuring
instances, so that the need to edit the configuration file
manually is reduced or eliminated.

* Instance Manager provides remote instance management. That is, it
runs on the host where you want to control MySQL Server instances,
but you can connect to it from a remote host to perform
instance-management operations.

The following sections describe MySQL Instance Manager operation in
more detail.

File: manual.info, Node: instance-manager-command-options, Next: instance-manager-configuration-files, Prev: instance-manager, Up: instance-manager

5.6.10.1 MySQL Instance Manager Command Options
...............................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

The MySQL Instance Manager supports a number of command options. For a
brief listing, invoke `mysqlmanager' with the `--help' option. Options
may be given on the command line or in the Instance Manager
configuration file. On Windows, the standard configuration file is
`my.ini' in the directory where Instance Manager is installed. On Unix,
the standard file is `/etc/my.cnf'. To specify a different
configuration file, start Instance Manager with the `--defaults-file'
option.

`mysqlmanager' supports the following options. It also reads option
files and supports the options for processing them described at *Note
option-file-options::.

* `--help', `-?'

Display a help message and exit.

* `--angel-pid-file=FILE_NAME'

The file in which the angel process records its process ID when
`mysqlmanager' runs in daemon mode (that is, when the
`--run-as-service' option is given). The default file name is
`mysqlmanager.angel.pid'.

If the `--angel-pid-file' option is not given, the default angel
PID file has the same name as the PID file except that any PID
file extension is replaced with an extension of `.angel.pid'. (For
example, `mysqlmanager.pid' becomes `mysqlmanager.angel.pid'.)

This option was added in MySQL 5.0.23.

* `--bind-address=IP'

The IP address to bind to.

* `--default-mysqld-path=PATH'

The path name of the MySQL Server binary. This path name is used
for all server instance sections in the configuration file for
which no `mysqld-path' option is present. The default value of
this option is the compiled-in path name, which depends on how the
MySQL distribution was configured. Example:
`--default-mysqld-path=/usr/sbin/mysqld'

* `--defaults-file=FILE_NAME'

Read Instance Manager and MySQL Server settings from the given
file. All configuration changes made by the Instance Manager will
be written to this file. This must be the first option on the
command line if it is used, and the file must exist.

If this option is not given, Instance Manager uses its standard
configuration file. On Windows, the standard file is `my.ini' in
the directory where Instance Manager is installed. On Unix, the
standard file is `/etc/my.cnf'.

* `--install'

On Windows, install Instance Manager as a Windows service. The
service name is `MySQL Manager'. This option was added in MySQL
5.0.11.

* `--log=FILE_NAME'

The path to the Instance Manager log file. This option has no
effect unless the `--run-as-service' option is also given. If the
file name specified for the option is a relative name, the log
file is created under the directory from which Instance Manager is
started. To ensure that the file is created in a specific
directory, specify it as a full path name.

If `--run-as-service' is given without `--log', the log file is
`mysqlmanager.log' in the data directory.

If `--run-as-service' is not given, log messages go to the
standard output. To capture log output, you can redirect Instance
Manager output to a file:

mysqlmanager > im.log

* `--monitoring-interval=SECONDS'

The interval in seconds for monitoring server instances. The
default value is 20 seconds. Instance Manager tries to connect to
each monitored (guarded) instance using the nonexisting
`MySQL_Instance_Manager' user account to check whether it is
available/not hanging. If the result of the connection attempt
indicates that the instance is unavailable, Instance Manager
performs several attempts to restart the instance.

Normally, the `MySQL_Instance_Manager' account does not exist, so
the connection attempts by Instance Manager cause the monitored
instance to produce messages in its general query log similar to
the following:

Access denied for user 'MySQL_Instance_M'@'localhost' (using password: YES)

The `nonguarded' option in the appropriate server instance section
disables monitoring for a particular instance. If the instance
dies after being started, Instance Manager will not restart it.
Instance Manager tries to connect to a nonguarded instance only
when you request the instance's status (for example, with the `SHOW
INSTANCES' status.

See *Note instance-manager-security-monitoring::, for more
information.

* `--passwd', `-P'

Prepare an entry for the password file, print it to the standard
output, and exit. You can redirect the output from Instance
Manager to a file to save the entry in the file. See also *Note
instance-manager-security-passwords::. This

* `--password-file=FILE_NAME'

The name of the file where the Instance Manager looks for users
and passwords. On Windows, the default is `mysqlmanager.passwd' in
the directory where Instance Manager is installed. On Unix, the
default file is `/etc/mysqlmanager.passwd'. See also *Note
instance-manager-security-passwords::.

* `--pid-file=FILE_NAME'

The process ID file to use. On Windows, the default file is
`mysqlmanager.pid' in the directory where Instance Manager is
installed. On Unix, the default is `mysqlmanager.pid' in the data
directory.

* `--port=PORT_NUM'

The port number to use when listening for TCP/IP connections from
clients. The default port number (assigned by IANA) is 2273.

* `--print-defaults'

Print the current defaults and exit. This must be the first option
on the command line if it is used.

* `--remove'

On Windows, removes Instance Manager as a Windows service. This
assumes that Instance Manager has been run with `--install'
previously. This option was added in MySQL 5.0.11.

* `--run-as-service'

On Unix, daemonize and start an angel process. The angel process
monitors Instance Manager and restarts it if it crashes. (The
angel process itself is simple and unlikely to crash.)

* `--socket=PATH'

On Unix, the socket file to use for incoming connections. The
default file is named `/tmp/mysqlmanager.sock'. This option has no
meaning on Windows.

* `--standalone'

This option is used on Windows to run Instance Manager in
standalone mode. You should specify it when you start Instance
Manager from the command line. This option was added in MySQL
5.0.13.

* `--user=USER_NAME'

On Unix, the user name of the system account to use for starting
and running `mysqlmanager'. This option generates a warning and
has no effect unless you start `mysqlmanager' as `root' (so that
it can change its effective user ID), or as the named user. It is
recommended that you configure `mysqlmanager' to run using the
same account used to run the *Note `mysqld': mysqld. server.
(`User' in this context refers to a system login account, not a
MySQL user listed in the grant tables.)

* `--version', `-V'

Display version information and exit.

* `--wait-timeout=N'

The number of seconds to wait for activity on an incoming
connection before closing it. The default is 28800 seconds (8
hours).

This option was added in MySQL 5.0.19. Before that, the timeout is
30 seconds and cannot be changed.

File: manual.info, Node: instance-manager-configuration-files, Next: instance-manager-startup-process, Prev: instance-manager-command-options, Up: instance-manager

5.6.10.2 MySQL Instance Manager Configuration Files
...................................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

Instance Manager uses its standard configuration file unless it is
started with a `--defaults-file' option that specifies a different
file. On Windows, the standard file is `my.ini' in the directory where
Instance Manager is installed. On Unix, the standard file is
`/etc/my.cnf'. (Prior to MySQL 5.0.10, the MySQL Instance Manager read
the same configuration files as the MySQL Server, including
`/etc/my.cnf', `~/.my.cnf', and so forth.)

Instance Manager reads options for itself from the `[manager]' section
of the configuration file, and options for server instances from
`[mysqld]' or `[mysqldN]' sections. The `[manager]' section contains any
of the options listed in *Note instance-manager-command-options::,
except for those specified as having to be given as the first option on
the command line. Here is a sample `[manager]' section:

# MySQL Instance Manager options section
[manager]
default-mysqld-path = /usr/local/mysql/libexec/mysqld
socket=/tmp/manager.sock
pid-file=/tmp/manager.pid
password-file = /home/cps/.mysqlmanager.passwd
monitoring-interval = 2
port = 1999
bind-address = 192.168.1.5

Each `[mysqld]' or `[mysqldN]' instance section specifies options given
by Instance Manager to a server instance at startup. These are mainly
common MySQL Server options (see *Note server-options::). In addition, a
`[mysqldN]' section can contain the options in the following list,
which are specific to Instance Manager. These options are interpreted by
Instance Manager itself; it does not pass them to the server when it
attempts to start that server.

*Warning*:

The Instance Manager-specific options must not be used in a `[mysqld]'
section. If a server is started without using Instance Manager, it will
not recognize these options and will fail to start properly.

* `mysqld-path = PATH'

The path name of the *Note `mysqld': mysqld. server binary to use
for the server instance.

* `nonguarded'

This option disables Instance Manager monitoring functionality for
the server instance. By default, an instance is guarded: At
Instance Manager start time, it starts the instance. It also
monitors the instance status and attempts to restart it if it
fails. At Instance Manager exit time, it stops the instance. None
of these things happen for nonguarded instances.

* `shutdown-delay = SECONDS'

The number of seconds Instance Manager should wait for the server
instance to shut down. The default value is 35 seconds. After the
delay expires, Instance Manager assumes that the instance is
hanging and attempts to terminate it. If you use `InnoDB' with
large tables, you should increase this value.

Here are some sample instance sections:

[mysqld1]
mysqld-path=/usr/local/mysql/libexec/mysqld
socket=/tmp/mysql.sock
port=3307
server_id=1
skip-stack-trace
core-file
skip-bdb
log-bin
log-error
log=mylog
log-slow-queries

[mysqld2]
nonguarded
port=3308
server_id=2
mysqld-path= /home/cps/mysql/trees/mysql-5.0/sql/mysqld
socket = /tmp/mysql.sock5
pid-file = /tmp/hostname.pid5
datadir= /home/cps/mysql_data/data_dir1
language=/home/cps/mysql/trees/mysql-5.0/sql/share/english
log-bin
log=/tmp/fordel.log

File: manual.info, Node: instance-manager-startup-process, Next: instance-manager-security-passwords, Prev: instance-manager-configuration-files, Up: instance-manager

5.6.10.3 Starting the MySQL Server with MySQL Instance Manager
..............................................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

This section discusses how Instance Manager starts server instances
when it starts. However, before you start Instance Manager, you should
set up a password file for it. Otherwise, you will not be able to
connect to Instance Manager to control it after it starts. For details
about creating Instance Manager accounts, see *Note
instance-manager-security-passwords::.

On Unix, the *Note `mysqld': mysqld. MySQL database server normally is
started with the *Note `mysql.server': mysql-server. script, which
usually resides in the `/etc/init.d/' directory. In MySQL 5.0.3, this
script invokes `mysqlmanager' (the MySQL Instance Manager binary) to
start MySQL. (In prior versions of MySQL the *Note `mysqld_safe':
mysqld-safe. script is used for this purpose.) Starting from MySQL
5.0.4, the behavior of the startup script was changed again to
incorporate both setup schemes. In version 5.0.4, the startup script
uses the old scheme (invoking *Note `mysqld_safe': mysqld-safe.) by
default, but one can set the `use_mysqld_safe' variable in the script to
`0' (zero) to use the MySQL Instance Manager to start a server.

Starting with MySQL 5.0.19, you can use Instance Manager if you modify
the `my.cnf' configuration file by adding `use-manager' to the
`[mysql.server]' section:

[mysql.server]
use-manager

When Instance Manager starts, it reads its configuration file if it
exists to find server instance sections and prepare a list of
instances. Instance sections have names of the form `[mysqld]' or
`[mysqldN]', where N is an unsigned integer (for example, `[mysqld1]',
`[mysqld2]', and so forth).

After preparing the list of instances, Instance Manager starts the
guarded instances in the list. If there are no instances, Instance
Manager creates an instance named `mysqld' and attempts to start it
with default (compiled-in) configuration values. This means that the
Instance Manager cannot find the *Note `mysqld': mysqld. program if it
is not installed in the default location. (*Note
installation-layouts::, describes default locations for components of
MySQL distributions.) If you have installed the MySQL server in a
nonstandard location, you should create the Instance Manager
configuration file.

Instance Manager also stops all guarded server instances when it shuts
down.

The permissible options for `[mysqldN]' server instance sections are
described in *Note instance-manager-configuration-files::. In these
sections, you can use a special `mysqld-path=PATH-TO-MYSQLD-BINARY'
option that is recognized only by Instance Manager. Use this option to
let Instance Manager know where the *Note `mysqld': mysqld. binary
resides. If there are multiple instances, it may also be necessary to
set other options such as `datadir' and `port', to ensure that each
instance has a different data directory and TCP/IP port number. *Note
multiple-servers::, discusses the configuration values that must differ
for each instance when you run multiple instance on the same machine.

*Warning*:

The `[mysqld]' instance section, if it exists, must not contain any
Instance Manager-specific options.

The typical Unix startup/shutdown cycle for a MySQL server with the
MySQL Instance Manager enabled is as follows:

1. The `/etc/init.d/mysql' script starts MySQL Instance Manager.

2. Instance Manager starts the guarded server instances and monitors
them.

3. If a server instance fails, Instance Manager restarts it.

4. If Instance Manager is shut down (for example, with the
`/etc/init.d/mysql stop' command), it shuts down all server
instances.

File: manual.info, Node: instance-manager-security-passwords, Next: instance-manager-security-monitoring, Prev: instance-manager-startup-process, Up: instance-manager

5.6.10.4 Instance Manager User and Password Management
......................................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

The Instance Manager stores its user information in a password file. On
Windows, the default is `mysqlmanager.passwd' in the directory where
Instance Manager is installed. On Unix, the default file is
`/etc/mysqlmanager.passwd'. To specify a different location for the
password file, use the `--password-file' option.

If the password file does not exist or contains no password entries,
you cannot connect to the Instance Manager.

*Note*:

Any Instance Manager process that is running to monitor server
instances does not notice changes to the password file. You must stop
it and restart it after making password entry changes.

Entries in the password file have the following format, where the two
fields are the account user name and encrypted password, separated by a
colon:

petr:*35110DC9B4D8140F5DE667E28C72DD2597B5C848

Instance Manager password encryption is the same as that used by MySQL
Server. It is a one-way operation; no means are provided for decrypting
encrypted passwords.

Instance Manager accounts differ somewhat from MySQL Server accounts:

* MySQL Server accounts are associated with a host name, user name,
and password (see *Note user-names::).

* Instance Manager accounts are associated with a user name and
password only.

This means that a client can connect to Instance Manager with a given
user name from any host. To limit connections so that clients can
connect only from the local host, start Instance Manager with the
`--bind-address=127.0.0.1' option so that it listens only to the local
network interface. Remote clients will not be able to connect. Local
clients can connect like this:

shell> mysql -h 127.0.0.1 -P 2273

To generate a new entry, invoke Instance Manager with the `--passwd'
option and append the output to the `/etc/mysqlmanager.passwd' file.
Here is an example:

shell> mysqlmanager --passwd >> /etc/mysqlmanager.passwd
Creating record for new user.
Enter user name: mike
Enter password: mikepass
Re-type password: mikepass

At the prompts, enter the user name and password for the new Instance
Manager user. You must enter the password twice. It does not echo to
the screen, so double entry guards against entering a different
password than you intend (if the two passwords do not match, no entry
is generated).

The preceding command causes the following line to be added to
`/etc/mysqlmanager.passwd':

mike:*BBF1F551DD9DD96A01E66EC7DDC073911BAD17BA

Use of the `--password'
(http://dev.mysql.com/doc/refman/5.1/en/instance-manager.html#option_mysqlmanager_password)
option fails if `mysqlmanager' is invoked directly from an IBM 5250
terminal. To work around this, use a command like the following from
the command line to generate the password entry:

shell> mysql -B --skip-column-name \
-e 'SELECT CONCAT("USER_NAME",":",PASSWORD("PASS_VAL"));'

The output from the command can be used an entry in the
`/etc/mysqlmanager.passwd' file.

File: manual.info, Node: instance-manager-security-monitoring, Next: instance-manager-security, Prev: instance-manager-security-passwords, Up: instance-manager

5.6.10.5 MySQL Server Instance Status Monitoring
................................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

To monitor the status of each guarded server instance, the MySQL
Instance Manager attempts to connect to the instance at regular
intervals using the `MySQL_Instance_Manager@localhost' user account
with a password of `check_connection'.

You are _not_ required to create this account for MySQL Server; in
fact, it is expected that it will not exist. Instance Manager can tell
that a server is operational if the server accepts the connection
attempt but refuses access for the account by returning a login error.
However, these failed connection attempts are logged by the server to
its general query log (see *Note query-log::).

Instance Manager also attempts a connection to nonguarded server
instances when you use the `SHOW INSTANCES' or `SHOW INSTANCE STATUS'
command. This is the only status monitoring done for nonguarded
instances.

Instance Manager knows if a server instance fails at startup because it
receives a status from the attempt. For an instance that starts but
later crashes, Instance Manager receives a signal because it is the
parent process of the instance.

File: manual.info, Node: instance-manager-security, Next: instance-manager-commands, Prev: instance-manager-security-monitoring, Up: instance-manager

5.6.10.6 Connecting to MySQL Instance Manager
.............................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

After you set up a password file for the MySQL Instance Manager and
Instance Manager is running, you can connect to it. The MySQL
client/server protocol is used to communicate with the Instance
Manager. For example, you can connect to it using the standard *Note
`mysql': mysql. client program:

shell> mysql --port=2273 --host=im.example.org --user=mysql --password

Instance Manager supports the version of the MySQL client/server
protocol used by the client tools and libraries distributed with MySQL
4.1 or later, so other programs that use the MySQL C API also can
connect to it.

File: manual.info, Node: instance-manager-commands, Prev: instance-manager-security, Up: instance-manager

5.6.10.7 MySQL Instance Manager Commands
........................................

*Important*:

MySQL Instance Manager is been deprecated in MySQL 5.1 and is removed
in MySQL 5.5.

After you connect to MySQL Instance Manager, you can issue commands.
The following general principles apply to Instance Manager command
execution:

* Commands that take an instance name fail if the name is not a
valid instance name.

* Commands that take an instance name fail if the instance does not
exist.

* Instance Manager maintains information about instance
configuration in an internal (in-memory) cache. Initially, this
information comes from the configuration file if it exists, but
some commands change the configuration of an instance. Commands
that modify the configuration file fail if the file does not exist
or is not accessible to Instance Manager.

* On Windows, the standard file is `my.ini' in the directory where
Instance Manager is installed. On Unix, the standard configuration
file is `/etc/my.cnf'. To specify a different configuration file,
start Instance Manager with the `--defaults-file' option.

* If a `[mysqld]' instance section exists in the configuration file,
it must not contain any Instance Manager-specific options (see
*Note instance-manager-configuration-files::). Therefore, you
must not add any of these options if you change the configuration
for an instance named `mysqld'.

The following list describes the commands that Instance Manager
accepts, with examples.

* `START INSTANCE INSTANCE_NAME'

This command attempts to start an offline instance. The command is
asynchronous; it does not wait for the instance to start.

mysql> START INSTANCE mysqld4;
Query OK, 0 rows affected (0,00 sec)

* `STOP INSTANCE INSTANCE_NAME'

This command attempts to stop an instance. The command is
synchronous; it waits for the instance to stop.

mysql> STOP INSTANCE mysqld4;
Query OK, 0 rows affected (0,00 sec)

* `SHOW INSTANCES'

Shows the names and status of all loaded instances.

* `SHOW INSTANCE STATUS INSTANCE_NAME'

Shows status and version information for an instance.

* `SHOW INSTANCE OPTIONS INSTANCE_NAME'

Shows the options used by an instance.

* `SHOW INSTANCE_NAME LOG FILES'

The command lists all log files used by the instance. The result
set contains the path to the log file and the log file size. If no
log file path is specified in the instance section of the
configuration file (for example, `log=/var/mysql.log'), the
Instance Manager tries to guess its placement. If Instance Manager
is unable to guess the log file placement you should specify the
log file location explicitly by using a log option in the
appropriate instance section of the configuration file.

Log options are described in *Note server-options::.

* `SHOW INSTANCE_NAME LOG {ERROR | SLOW | GENERAL}
SIZE[,OFFSET_FROM_END]'

This command retrieves a portion of the specified log file.
Because most users are interested in the latest log messages, the
SIZE parameter defines the number of bytes to retrieve from the
end of the log. To retrieve data from the middle of the log file,
specify the optional OFFSET_FROM_END parameter. The following
example retrieves 21 bytes of data, starting 23 bytes before the
end of the log file and ending 2 bytes before the end:

mysql> SHOW mysqld LOG GENERAL 21, 2;
+---------------------+
| Log |
+---------------------+
| using password: YES |
+---------------------+

* `SET INSTANCE_NAME.OPTION_NAME[=OPTION_VALUE]'

This command edits the specified instance's configuration section
to change or add instance options. The option is added to the
section is it is not already present. Otherwise, the new setting
replaces the existing one.

mysql> SET mysqld2.port=3322;
Query OK, 0 rows affected (0.00 sec)

Changes made to the configuration file do not take effect until
the MySQL server is restarted. In addition, these changes are not
stored in the instance manager's local cache of instance settings
until a `FLUSH INSTANCES' command is executed.

* `UNSET INSTANCE_NAME.OPTION_NAME'

This command removes an option from an instance's configuration
section.

mysql> UNSET mysqld2.port;
Query OK, 0 rows affected (0.00 sec)

* `FLUSH INSTANCES'

This command forces Instance Manager reread the configuration file
and to refresh internal structures. This command should be
performed after editing the configuration file. The command does
not restart instances.

mysql> FLUSH INSTANCES;
Query OK, 0 rows affected (0.04 sec)

`FLUSH INSTANCES' is deprecated and will be removed in MySQL 5.2.

File: manual.info, Node: mysql-convert-table-format, Next: mysql-explain-log, Prev: instance-manager, Up: programs-admin-utils

5.6.11 `mysql_convert_table_format' -- Convert Tables to Use a Given Storage Engine
-----------------------------------------------------------------------------------

*Note `mysql_convert_table_format': mysql-convert-table-format.
converts the tables in a database to use a particular storage engine
(`MyISAM' by default). *Note `mysql_convert_table_format':
mysql-convert-table-format. is written in Perl and requires that the
`DBI' and `DBD::mysql' Perl modules be installed (see *Note
perl-support::).

Invoke *Note `mysql_convert_table_format': mysql-convert-table-format.
like this:

shell> mysql_convert_table_format [OPTIONS]DB_NAME

The DB_NAME argument indicates the database containing the tables to be
converted.

*Note `mysql_convert_table_format': mysql-convert-table-format.
supports the options described in the following list.

* `--help'

Display a help message and exit.

* `--force'

Continue even if errors occur.

* `--host=HOST_NAME'

Connect to the MySQL server on the given host.

* `--password=PASSWORD'

The password to use when connecting to the server. Note that the
password value is not optional for this option, unlike for other
MySQL programs.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--port=PORT_NUM'

The TCP/IP port number to use for the connection.

* `--socket=PATH'

For connections to `localhost', the Unix socket file to use.

* `--type=ENGINE_NAME'

Specify the storage engine that the tables should be converted to
use. The default is `MyISAM' if this option is not given.

* `--user=USER_NAME'

The MySQL user name to use when connecting to the server.

* `--verbose'

Verbose mode. Print more information about what the program does.

* `--version'

Display version information and exit.

File: manual.info, Node: mysql-explain-log, Next: mysql-find-rows, Prev: mysql-convert-table-format, Up: programs-admin-utils

5.6.12 `mysql_explain_log' -- Use EXPLAIN on Statements in Query Log
--------------------------------------------------------------------

*Note `mysql_explain_log': mysql-explain-log. reads its standard input
for query log contents. It uses *Note `EXPLAIN': explain. to analyze
*Note `SELECT': select. statements found in the input. *Note `UPDATE':
update. statements are rewritten to *Note `SELECT': select. statements
and also analyzed with *Note `EXPLAIN': explain. *Note
`mysql_explain_log': mysql-explain-log. then displays a summary of its
results.

The results may assist you in determining which queries result in table
scans and where it would be beneficial to add indexes to your tables.

Invoke *Note `mysql_explain_log': mysql-explain-log. like this, where
LOG_FILE contains all or part of a MySQL query log:

shell> mysql_explain_log [OPTIONS] < LOG_FILE

*Note `mysql_explain_log': mysql-explain-log. understands the following
options:

* `--help', `-?'

Display a help message and exit.

* `--date=YYMMDD', `-d YYMMDD'

Select entries from the log only for the given date.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--password=PASSWORD', `-p PASSWORD'

The password to use when connecting to the server.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::.

* `--printerror=1', `-e 1'

Enable error output.

* `--socket=PATH', `-S PATH'

For connections to `localhost', the Unix socket file to use, or,
on Windows, the name of the named pipe to use.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

File: manual.info, Node: mysql-find-rows, Next: mysql-fix-extensions, Prev: mysql-explain-log, Up: programs-admin-utils

5.6.13 `mysql_find_rows' -- Extract SQL Statements from Files
-------------------------------------------------------------

*Note `mysql_find_rows': mysql-find-rows. reads files containing SQL
statements and extracts statements that match a given regular
expression or that contain `USE DB_NAME' or *Note `SET': set-option.
statements. The utility was written for use with update log files (as
used prior to MySQL 5.0) and as such expects statements to be
terminated with semicolon (`;') characters. It may be useful with other
files that contain SQL statements as long as statements are terminated
with semicolons.

Invoke *Note `mysql_find_rows': mysql-find-rows. like this:

shell> mysql_find_rows [OPTIONS] [FILE_NAME ...]

Each FILE_NAME argument should be the name of file containing SQL
statements. If no file names are given, *Note `mysql_find_rows':
mysql-find-rows. reads the standard input.

Examples:

mysql_find_rows --regexp=problem_table --rows=20 < update.log
mysql_find_rows --regexp=problem_table update-log.1 update-log.2

*Note `mysql_find_rows': mysql-find-rows. supports the following
options:

* `--help', `--Information'

Display a help message and exit.

* `--regexp=PATTERN'

Display queries that match the pattern.

* `--rows=N'

Quit after displaying N queries.

* `--skip-use-db'

Do not include `USE DB_NAME' statements in the output.

* `--start_row=N'

Start output from this row.

File: manual.info, Node: mysql-fix-extensions, Next: mysql-setpermission, Prev: mysql-find-rows, Up: programs-admin-utils

5.6.14 `mysql_fix_extensions' -- Normalize Table File Name Extensions
---------------------------------------------------------------------

*Note `mysql_fix_extensions': mysql-fix-extensions. converts the
extensions for `MyISAM' (or `ISAM') table files to their canonical
forms. It looks for files with extensions matching any lettercase
variant of `.frm', `.myd', `.myi', `.isd', and `.ism' and renames them
to have extensions of `.frm', `.MYD', `.MYI', `.ISD', and `.ISM',
respectively. This can be useful after transferring the files from a
system with case-insensitive file names (such as Windows) to a system
with case-sensitive file names.

Invoke *Note `mysql_fix_extensions': mysql-fix-extensions. like this,
where DATA_DIR is the path name to the MySQL data directory.

shell> mysql_fix_extensions DATA_DIR

File: manual.info, Node: mysql-setpermission, Next: mysql-tableinfo, Prev: mysql-fix-extensions, Up: programs-admin-utils

5.6.15 `mysql_setpermission' -- Interactively Set Permissions in Grant Tables
-----------------------------------------------------------------------------

*Note `mysql_setpermission': mysql-setpermission. is a Perl script that
was originally written and contributed by Luuk de Boer. It
interactively sets permissions in the MySQL grant tables. *Note
`mysql_setpermission': mysql-setpermission. is written in Perl and
requires that the `DBI' and `DBD::mysql' Perl modules be installed (see
*Note perl-support::).

Invoke *Note `mysql_setpermission': mysql-setpermission. like this:

shell> mysql_setpermission [OPTIONS]

OPTIONS should be either `--help' to display the help message, or
options that indicate how to connect to the MySQL server. The account
used when you connect determines which permissions you have when
attempting to modify existing permissions in the grant tables.

`mysql_setpermissions' also reads options from the `[client]' and
`[perl]' groups in the `.my.cnf' file in your home directory, if the
file exists.

*Note `mysql_setpermission': mysql-setpermission. supports the following
options:

* `--help'

Display a help message and exit.

* `--host=HOST_NAME'

Connect to the MySQL server on the given host.

* `--password=PASSWORD'

The password to use when connecting to the server. Note that the
password value is not optional for this option, unlike for other
MySQL programs.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::. You can use an
option file to avoid giving the password on the command line.

* `--port=PORT_NUM'

The TCP/IP port number to use for the connection.

* `--socket=PATH'

For connections to `localhost', the Unix socket file to use.

* `--user=USER_NAME'

The MySQL user name to use when connecting to the server.

File: manual.info, Node: mysql-tableinfo, Next: mysql-waitpid, Prev: mysql-setpermission, Up: programs-admin-utils

5.6.16 `mysql_tableinfo' -- Generate Database Metadata
------------------------------------------------------

*Note `mysql_tableinfo': mysql-tableinfo. creates tables and populates
them with database metadata. It uses *Note `SHOW DATABASES':
show-databases, *Note `SHOW TABLES': show-tables, *Note `SHOW TABLE
STATUS': show-table-status, *Note `SHOW COLUMNS': show-columns, and
*Note `SHOW INDEX': show-index. to obtain the metadata.

In MySQL 5.0 and up, the `INFORMATION_SCHEMA' database contains the
same kind of information in the *Note `SCHEMATA': schemata-table, *Note
`TABLES': tables-table, *Note `COLUMNS': columns-table, and *Note
`STATISTICS': statistics-table. tables. See *Note information-schema::.

Invoke *Note `mysql_tableinfo': mysql-tableinfo. like this:

shell> mysql_tableinfo [OPTIONS] DB_NAME [DB_LIKE [TBL_LIKE]]

The DB_NAME argument indicates which database *Note `mysql_tableinfo':
mysql-tableinfo. should use as the location for the metadata tables.
The database will be created if it does not exist. The tables will be
named `db', `tbl' (or `tbl_status'), `col', and `idx'.

If the DB_LIKE or TBL_LIKE arguments are given, they are used as
patterns and metadata is generated only for databases or tables that
match the patterns. These arguments default to `%' if not given.

Examples:

mysql_tableinfo info
mysql_tableinfo info world
mysql_tableinfo info mydb tmp%

Each of the commands stores information into tables in the `info'
database. The first stores information for all databases and tables.
The second stores information for all tables in the `world' database.
The third stores information for tables in the `mydb' database that
have names matching the pattern `tmp%'.

*Note `mysql_tableinfo': mysql-tableinfo. supports the following
options:

*`mysql_tableinfo' Options*

Format Option File Description IntroductionDeprecatedRemoved
-clear clear Before populating each
metadata table, drop it if
it exists
-clear-only clear-only Similar to -clear, but exits
after dropping the metadata
tables to be populated.
-col col Generate column metadata
into the col table
-help Display help message and exit
-host=host_namehost Connect to the MySQL server
on the given host
-idx idx Generate index metadata into
the idx table
-password=passwordpassword The password to use when
connecting to the server -
not optional
-port=port_numport The TCP/IP port number to
use for the connection
-prefix=prefix_strprefix Add prefix_str at the
beginning of each metadata
table name
-quiet quiet Be silent except for errors
-socket=pathsocket Display version information
and exit
-tbl-status tbl-status Use SHOW TABLE STATUS
instead of SHOW TABLES
-user=user_name,user The mysql_tableinfo user
name to use when connecting
to the server

* `--help'

Display a help message and exit.

* `--clear'

Before populating each metadata table, drop it if it exists.

* `--clear-only'

Similar to `--clear', but exits after dropping the metadata tables
to be populated.

* `--col'

Generate column metadata into the `col' table.

* `--host=HOST_NAME', `-h HOST_NAME'

Connect to the MySQL server on the given host.

* `--idx'

Generate index metadata into the `idx' table.

* `--password=PASSWORD', `-pPASSWORD'

The password to use when connecting to the server. Note that the
password value is not optional for this option, unlike for other
MySQL programs. You can use an option file to avoid giving the
password on the command line.

Specifying a password on the command line should be considered
insecure. See *Note password-security-user::.

* `--port=PORT_NUM', `-P PORT_NUM'

The TCP/IP port number to use for the connection.

* `--prefix=PREFIX_STR'

Add PREFIX_STR at the beginning of each metadata table name.

* `--quiet', `-q'

Be silent except for errors.

* `--socket=PATH', `-S PATH'

The Unix socket file to use for the connection.

* `--tbl-status'

Use *Note `SHOW TABLE STATUS': show-table-status. instead of *Note
`SHOW TABLES': show-tables. This provides more complete
information, but is slower.

* `--user=USER_NAME', `-u USER_NAME'

The MySQL user name to use when connecting to the server.

File: manual.info, Node: mysql-waitpid, Next: mysql-zap, Prev: mysql-tableinfo, Up: programs-admin-utils

5.6.17 `mysql_waitpid' -- Kill Process and Wait for Its Termination
-------------------------------------------------------------------

*Note `mysql_waitpid': mysql-waitpid. signals a process to terminate
and waits for the process to exit. It uses the `kill()' system call and
Unix signals, so it runs on Unix and Unix-like systems.

Invoke *Note `mysql_waitpid': mysql-waitpid. like this:

shell> mysql_waitpid [OPTIONS] PID WAIT_TIME

*Note `mysql_waitpid': mysql-waitpid. sends signal 0 to the process
identified by PID and waits up to WAIT_TIME seconds for the process to
terminate. PID and WAIT_TIME must be positive integers.

If process termination occurs within the wait time or the process does
not exist, *Note `mysql_waitpid': mysql-waitpid. returns 0. Otherwise,
it returns 1.

If the `kill()' system call cannot handle signal 0, `mysql_waitpid()'
uses signal 1 instead.

*Note `mysql_waitpid': mysql-waitpid. supports the following options:

* `--help', `-?', `-I'

Display a help message and exit.

* `--verbose', `-v'

Verbose mode. Display a warning if signal 0 could not be used and
signal 1 is used instead.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: mysql-zap, Prev: mysql-waitpid, Up: programs-admin-utils

5.6.18 `mysql_zap' -- Kill Processes That Match a Pattern
---------------------------------------------------------

*Note `mysql_zap': mysql-zap. kills processes that match a pattern. It
uses the `ps' command and Unix signals, so it runs on Unix and
Unix-like systems.

Invoke *Note `mysql_zap': mysql-zap. like this:

shell> mysql_zap [-SIGNAL] [-?Ift] PATTERN

A process matches if its output line from the `ps' command contains the
pattern. By default, *Note `mysql_zap': mysql-zap. asks for
confirmation for each process. Respond `y' to kill the process, or `q'
to exit *Note `mysql_zap': mysql-zap. For any other response, *Note
`mysql_zap': mysql-zap. does not attempt to kill the process.

If the `-SIGNAL' option is given, it specifies the name or number of
the signal to send to each process. Otherwise, *Note `mysql_zap':
mysql-zap. tries first with `TERM' (signal 15) and then with *Note
`KILL': kill. (signal 9).

*Note `mysql_zap': mysql-zap. supports the following additional options:

* `--help', `-?', `-I'

Display a help message and exit.

* `-f'

Force mode. *Note `mysql_zap': mysql-zap. attempts to kill each
process without confirmation.

* `-t'

Test mode. Display information about each process but do not kill
it.

File: manual.info, Node: programs-development, Next: programs-miscellaneous, Prev: programs-admin-utils, Up: programs

5.7 MySQL Program Development Utilities
=======================================

* Menu:

* msql2mysql:: `msql2mysql' --- Convert mSQL Programs for Use with MySQL
* mysql-config:: `mysql_config' --- Get Compile Options for Compiling Clients
* my-print-defaults:: `my_print_defaults' --- Display Options from Option Files
* resolve-stack-dump:: `resolve_stack_dump' --- Resolve Numeric Stack Trace Dump to Symbols

This section describes some utilities that you may find useful when
developing MySQL programs.

In shell scripts, you can use the *Note `my_print_defaults':
my-print-defaults. program to parse option files and see what options
would be used by a given program. The following example shows the
output that *Note `my_print_defaults': my-print-defaults. might
produce when asked to show the options found in the `[client]' and
`[mysql]' groups:

shell> my_print_defaults client mysql
--port=3306
--socket=/tmp/mysql.sock
--no-auto-rehash

Note for developers: Option file handling is implemented in the C
client library simply by processing all options in the appropriate
group or groups before any command-line arguments. This works well for
programs that use the last instance of an option that is specified
multiple times. If you have a C or C++ program that handles multiply
specified options this way but that doesn't read option files, you need
add only two lines to give it that capability. Check the source code of
any of the standard MySQL clients to see how to do this.

Several other language interfaces to MySQL are based on the C client
library, and some of them provide a way to access option file contents.
These include Perl and Python. For details, see the documentation for
your preferred interface.

File: manual.info, Node: msql2mysql, Next: mysql-config, Prev: programs-development, Up: programs-development

5.7.1 `msql2mysql' -- Convert mSQL Programs for Use with MySQL
--------------------------------------------------------------

Initially, the MySQL C API was developed to be very similar to that for
the mSQL database system. Because of this, mSQL programs often can be
converted relatively easily for use with MySQL by changing the names of
the C API functions.

The *Note `msql2mysql': msql2mysql. utility performs the conversion of
mSQL C API function calls to their MySQL equivalents. *Note
`msql2mysql': msql2mysql. converts the input file in place, so make a
copy of the original before converting it. For example, use *Note
`msql2mysql': msql2mysql. like this:

shell> cp client-prog.c client-prog.c.orig
shell> msql2mysql client-prog.c
client-prog.c converted

Then examine `client-prog.c' and make any post-conversion revisions
that may be necessary.

*Note `msql2mysql': msql2mysql. uses the *Note `replace':
replace-utility. utility to make the function name substitutions. See
*Note replace-utility::.

File: manual.info, Node: mysql-config, Next: my-print-defaults, Prev: msql2mysql, Up: programs-development

5.7.2 `mysql_config' -- Get Compile Options for Compiling Clients
-----------------------------------------------------------------

*Note `mysql_config': mysql-config. provides you with useful
information for compiling your MySQL client and connecting it to MySQL.

*Note `mysql_config': mysql-config. supports the following options.

* `--cflags'

Compiler flags to find include files and critical compiler flags
and defines used when compiling the `libmysqlclient' library. The
options returned are tied to the specific compiler that was used
when the library was created and might clash with the settings for
your own compiler. Use `--include' for more portable options that
contain only include paths.

* `--include'

Compiler options to find MySQL include files.

* `--libmysqld-libs', `--embedded'

Libraries and options required to link with the MySQL embedded
server.

* `--libs'

Libraries and options required to link with the MySQL client
library.

* `--libs_r'

Libraries and options required to link with the thread-safe MySQL
client library.

* `--port'

The default TCP/IP port number, defined when configuring MySQL.

* `--socket'

The default Unix socket file, defined when configuring MySQL.

* `--version'

Version number for the MySQL distribution.

If you invoke *Note `mysql_config': mysql-config. with no options, it
displays a list of all options that it supports, and their values:

shell> mysql_config
Usage: /usr/local/mysql/bin/mysql_config [options]
Options:
--cflags [-I/usr/local/mysql/include/mysql -mcpu=pentiumpro]
--include [-I/usr/local/mysql/include/mysql]
--libs [-L/usr/local/mysql/lib/mysql -lmysqlclient -lz
-lcrypt -lnsl -lm -L/usr/lib -lssl -lcrypto]
--libs_r [-L/usr/local/mysql/lib/mysql -lmysqlclient_r
-lpthread -lz -lcrypt -lnsl -lm -lpthread]
--socket [/tmp/mysql.sock]
--port [3306]
--version [4.0.16]
--libmysqld-libs [-L/usr/local/mysql/lib/mysql -lmysqld -lpthread -lz
-lcrypt -lnsl -lm -lpthread -lrt]

You can use *Note `mysql_config': mysql-config. within a command line
to include the value that it displays for a particular option. For
example, to compile a MySQL client program, use *Note `mysql_config':
mysql-config. as follows:

shell> CFG=/usr/local/mysql/bin/mysql_config
shell> sh -c "gcc -o progname `$CFG --include` progname.c `$CFG --libs`"

When you use *Note `mysql_config': mysql-config. this way, be sure to
invoke it within backtick (```'') characters. That tells the shell to
execute it and substitute its output into the surrounding command.

File: manual.info, Node: my-print-defaults, Next: resolve-stack-dump, Prev: mysql-config, Up: programs-development

5.7.3 `my_print_defaults' -- Display Options from Option Files
--------------------------------------------------------------

*Note `my_print_defaults': my-print-defaults. displays the options that
are present in option groups of option files. The output indicates what
options will be used by programs that read the specified option groups.
For example, the *Note `mysqlcheck': mysqlcheck. program reads the
`[mysqlcheck]' and `[client]' option groups. To see what options are
present in those groups in the standard option files, invoke *Note
`my_print_defaults': my-print-defaults. like this:

shell> my_print_defaults mysqlcheck client
--user=myusername
--password=secret
--host=localhost

The output consists of options, one per line, in the form that they
would be specified on the command line.

*Note `my_print_defaults': my-print-defaults. supports the following
options.

* `--help', `-?'

Display a help message and exit.

* `--config-file=FILE_NAME',

`--defaults-file=FILE_NAME', `-c FILE_NAME'

Read only the given option file.

* `--debug=DEBUG_OPTIONS', `-# DEBUG_OPTIONS'

Write a debugging log. A typical DEBUG_OPTIONS string is
`'d:t:o,FILE_NAME''. The default is
`'d:t:o,/tmp/my_print_defaults.trace''.

* `--defaults-extra-file=FILE_NAME',

`--extra-file=FILE_NAME', `-e FILE_NAME'

Read this option file after the global option file but (on Unix)
before the user option file.

* `--defaults-group-suffix=SUFFIX', `-g SUFFIX'

In addition to the groups named on the command line, read groups
that have the given suffix.

* `--no-defaults', `-n'

Return an empty string.

* `--verbose', `-v'

Verbose mode. Print more information about what the program does.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: resolve-stack-dump, Prev: my-print-defaults, Up: programs-development

5.7.4 `resolve_stack_dump' -- Resolve Numeric Stack Trace Dump to Symbols
-------------------------------------------------------------------------

*Note `resolve_stack_dump': resolve-stack-dump. resolves a numeric stack
dump to symbols.

Invoke *Note `resolve_stack_dump': resolve-stack-dump. like this:

shell> resolve_stack_dump [OPTIONS] SYMBOLS_FILE [NUMERIC_DUMP_FILE]

The symbols file should include the output from the `nm --numeric-sort
mysqld' command. The numeric dump file should contain a numeric stack
track from *Note `mysqld': mysqld. If no numeric dump file is named on
the command line, the stack trace is read from the standard input.

*Note `resolve_stack_dump': resolve-stack-dump. supports the following
options.

* `--help', `-h'

Display a help message and exit.

* `--numeric-dump-file=FILE_NAME', `-n FILE_NAME'

Read the stack trace from the given file.

* `--symbols-file=FILE_NAME', `-s FILE_NAME'

Use the given symbols file.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: programs-miscellaneous, Prev: programs-development, Up: programs

5.8 Miscellaneous Programs
==========================

* Menu:

* perror:: `perror' --- Explain Error Codes
* replace-utility:: `replace' --- A String-Replacement Utility
* resolveip:: `resolveip' --- Resolve Host name to IP Address or Vice Versa

File: manual.info, Node: perror, Next: replace-utility, Prev: programs-miscellaneous, Up: programs-miscellaneous

5.8.1 `perror' -- Explain Error Codes
-------------------------------------

For most system errors, MySQL displays, in addition to an internal text
message, the system error code in one of the following styles:

message ... (errno: #)
message ... (Errcode: #)

You can find out what the error code means by examining the
documentation for your system or by using the *Note `perror': perror.
utility.

*Note `perror': perror. prints a description for a system error code or
for a storage engine (table handler) error code.

Invoke *Note `perror': perror. like this:

shell> perror [OPTIONS] ERRORCODE ...

Example:

shell> perror 13 64
OS error code 13: Permission denied
OS error code 64: Machine is not on the network

To obtain the error message for a MySQL Cluster error code, invoke
*Note `perror': perror. with the `--ndb' option:

shell> perror --ndb ERRORCODE

Note that the meaning of system error messages may be dependent on your
operating system. A given error code may mean different things on
different operating systems.

*Note `perror': perror. supports the following options.

* `--help', `--info', `-I', `-?'

Display a help message and exit.

* `--ndb'

Print the error message for a MySQL Cluster error code.

* `--silent', `-s'

Silent mode. Print only the error message.

* `--verbose', `-v'

Verbose mode. Print error code and message. This is the default
behavior.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: replace-utility, Next: resolveip, Prev: perror, Up: programs-miscellaneous

5.8.2 `replace' -- A String-Replacement Utility
-----------------------------------------------

The *Note `replace': replace-utility. utility program changes strings
in place in files or on the standard input.

Invoke *Note `replace': replace-utility. in one of the following ways:

shell> replace FROM TO [FROM TO] ... -- FILE_NAME [FILE_NAME] ...
shell> replace FROM TO [FROM TO] ... < FILE_NAME

FROM represents a string to look for and TO represents its replacement.
There can be one or more pairs of strings.

Use the `--' option to indicate where the string-replacement list ends
and the file names begin. In this case, any file named on the command
line is modified in place, so you may want to make a copy of the
original before converting it. REPLACE prints a message indicating
which of the input files it actually modifies.

If the `--' option is not given, *Note `replace': replace-utility.
reads the standard input and writes to the standard output.

*Note `replace': replace-utility. uses a finite state machine to match
longer strings first. It can be used to swap strings. For example, the
following command swaps `a' and `b' in the given files, `file1' and
`file2':

shell> replace a b b a -- file1 file2 ...

The *Note `replace': replace-utility. program is used by *Note
`msql2mysql': msql2mysql. See *Note msql2mysql::.

*Note `replace': replace-utility. supports the following options.

* `-?', `-I'

Display a help message and exit.

* `-#DEBUG_OPTIONS'

Enable debugging.

* `-s'

Silent mode. Print less information what the program does.

* `-v'

Verbose mode. Print more information about what the program does.

* `-V'

Display version information and exit.

File: manual.info, Node: resolveip, Prev: replace-utility, Up: programs-miscellaneous

5.8.3 `resolveip' -- Resolve Host name to IP Address or Vice Versa
------------------------------------------------------------------

The *Note `resolveip': resolveip. utility resolves host names to IP
addresses and vice versa.

Invoke *Note `resolveip': resolveip. like this:

shell> resolveip [OPTIONS] {HOST_NAME|IP-ADDR} ...

*Note `resolveip': resolveip. supports the following options.

* `--help', `--info', `-?', `-I'

Display a help message and exit.

* `--silent', `-s'

Silent mode. Produce less output.

* `--version', `-V'

Display version information and exit.

File: manual.info, Node: server-administration, Next: backup-and-recovery, Prev: programs, Up: Top

6 MySQL Server Administration
*****************************

* Menu:

* mysqld-server:: The MySQL Server
* server-logs:: MySQL Server Logs
* security:: General Security Issues
* privilege-system:: The MySQL Access Privilege System
* user-account-management:: MySQL User Account Management
* multiple-servers:: Running Multiple MySQL Servers on the Same Machine

End of Product Lifecycle

MySQL Server (*Note `mysqld': mysqld.) is the main program that does
most of the work in a MySQL installation. This section provides an
overview of MySQL Server and covers topics that deal with administering
a MySQL installation:

* Server configuration

* The server log files

* Security issues and user-account management

* Management of multiple servers on a single machine

File: manual.info, Node: mysqld-server, Next: server-logs, Prev: server-administration, Up: server-administration

6.1 The MySQL Server
====================

* Menu:

* mysqld-option-tables:: Server Option and Variable Reference
* server-options:: Server Command Options
* server-system-variables:: Server System Variables
* using-system-variables:: Using System Variables
* server-status-variables:: Server Status Variables
* server-sql-mode:: Server SQL Modes
* server-side-help-support:: Server-Side Help
* server-signal-response:: Server Response to Signals
* server-shutdown:: The Shutdown Process

*Note `mysqld': mysqld. is the MySQL server. The following discussion
covers these MySQL server configuration topics:

* Startup options that the server supports

* Server system variables

* Server status variables

* How to set the server SQL mode

* The server shutdown process

*Note*:

Not all storage engines are supported by all MySQL server binaries and
configurations. To find out how to determine which storage engines your
MySQL server installation supports, see *Note show-engines::.

File: manual.info, Node: mysqld-option-tables, Next: server-options, Prev: mysqld-server, Up: mysqld-server

6.1.1 Server Option and Variable Reference
------------------------------------------

The following table provides a list of all the command line options,
server and status variables applicable within `mysqld'.

The table lists command-line options (Cmd-line), options valid in
configuration files (Option file), server system variables (System
Var), and status variables (Status var) in one unified list, with
notification of where each option/variable is valid. If a server option
set on the command line or in an option file differs from the name of
the corresponding server system or status variable, the variable name
is noted immediately below the corresponding option. For status
variables, the scope of the variable is shown (Scope) as either global,
session, or both. Please see the corresponding sections for details on
setting and using the options and variables. Where appropriate, a
direct link to further information on the item as available.

For a version of this table that is specific to MySQL Cluster, see
*Note mysql-cluster-option-tables::.

*Option/Variable Summary*

Name Cmd-Line Option file System Var Status Var Var Scope Dynamic
abort-slave-event-countYes Yes
Aborted_clients Yes Global No
Aborted_connects Yes Global No
allow-suspicious-udfsYes Yes
ansi Yes Yes
auto_increment_incrementYes Yes Yes Both Yes
auto_increment_offsetYes Yes Yes Both Yes
autocommit Yes Yes Yes Session Yes
automatic_sp_privileges Yes Global Yes
back_log Yes Yes Yes Global No
basedir Yes Yes Yes Global No
bdb_cache_size Yes Yes Yes Global No
bdb-home Yes Yes Global No
- _Variable_: Yes Global No
bdb_home
bdb-lock-detectYes Yes Global No
- _Variable_: Yes Global No
bdb_lock_detect
bdb_log_buffer_sizeYes Yes Yes Global No
bdb-logdir Yes Yes Global No
- _Variable_: Yes Global No
bdb_logdir
bdb_max_lock Yes Yes Yes Global No
bdb-no-recover Yes Yes
bdb-shared-dataYes Yes Global No
- _Variable_: Yes Global No
bdb_shared_data
bdb-tmpdir Yes Yes Global No
- _Variable_: Yes Global No
bdb_tmpdir
big-tables Yes Yes Session Yes
- _Variable_: Yes Session Yes
big_tables
bind-address Yes Yes Yes Global No
Binlog_cache_disk_use Yes Global No
binlog_cache_sizeYes Yes Yes Global Yes
Binlog_cache_use Yes Global No
binlog-do-db Yes Yes
binlog-ignore-dbYes Yes
bootstrap Yes Yes
bulk_insert_buffer_sizeYes Yes Yes Both Yes
Bytes_received Yes Both No
Bytes_sent Yes Both No
character_set_client Yes Both Yes
character-set-client-handshakeYes Yes
character_set_connection Yes Both Yes
character_set_database Yes Both Yes
This option
is dynamic,
but only the
server should
set this
information.
You should
not set the
value of this
variable
manually.
character-set-filesystemYes Yes Both Yes
- _Variable_: Yes Both Yes
character_set_filesystem
character_set_results Yes Both Yes
character-set-serverYes Yes Both Yes
- _Variable_: Yes Both Yes
character_set_server
character_set_system Yes Global No
character-sets-dirYes Yes Global No
- _Variable_: Yes Global No
character_sets_dir
chroot Yes Yes
collation_connection Yes Both Yes
collation_database Yes Both Yes
This option
is dynamic,
but only the
server should
set this
information.
You should
not set the
value of this
variable
manually.
collation-serverYes Yes Both Yes
- _Variable_: Yes Both Yes
collation_server
Com_admin_commands Yes Both No
Com_alter_db Yes Both No
Com_alter_event Yes Both No
Com_alter_table Yes Both No
Com_analyze Yes Both No
Com_backup_table Yes Both No
Com_begin Yes Both No
Com_call_procedure Yes Both No
Com_change_db Yes Both No
Com_change_master Yes Both No
Com_check Yes Both No
Com_checksum Yes Both No
Com_commit Yes Both No
Com_create_db Yes Both No
Com_create_event Yes Both No
Com_create_function Yes Both No
Com_create_index Yes Both No
Com_create_table Yes Both No
Com_create_user Yes Both No
Com_dealloc_sql Yes Both No
Com_delete Yes Both No
Com_delete_multi Yes Both No
Com_do Yes Both No
Com_drop_db Yes Both No
Com_drop_event Yes Both No
Com_drop_function Yes Both No
Com_drop_index Yes Both No
Com_drop_table Yes Both No
Com_drop_user Yes Both No
Com_execute_sql Yes Both No
Com_flush Yes Both No
Com_grant Yes Both No
Com_ha_close Yes Both No
Com_ha_open Yes Both No
Com_ha_read Yes Both No
Com_help Yes Both No
Com_insert Yes Both No
Com_insert_select Yes Both No
Com_kill Yes Both No
Com_load Yes Both No
Com_lock_tables Yes Both No
Com_optimize Yes Both No
Com_preload_keys Yes Both No
Com_prepare_sql Yes Both No
Com_purge Yes Both No
Com_purge_before_date Yes Both No
Com_rename_table Yes Both No
Com_repair Yes Both No
Com_replace Yes Both No
Com_replace_select Yes Both No
Com_reset Yes Both No
Com_restore_table Yes Both No
Com_revoke Yes Both No
Com_revoke_all Yes Both No
Com_rollback Yes Both No
Com_savepoint Yes Both No
Com_select Yes Both No
Com_set_option Yes Both No
Com_show_binlog_events Yes Both No
Com_show_binlogs Yes Both No
Com_show_charsets Yes Both No
Com_show_collations Yes Both No
Com_show_column_types Yes Both No
Com_show_create_db Yes Both No
Com_show_create_event Yes Both No
Com_show_create_table Yes Both No
Com_show_databases Yes Both No
Com_show_engine_logs Yes Both No
Com_show_engine_mutex Yes Both No
Com_show_engine_status Yes Both No
Com_show_errors Yes Both No
Com_show_events Yes Both No
Com_show_fields Yes Both No
Com_show_grants Yes Both No
Com_show_innodb_status Yes Both No
Com_show_keys Yes Both No
Com_show_logs Yes Both No
Com_show_master_status Yes Both No
Com_show_ndb_status Yes Both No
Com_show_new_master Yes Both No
Com_show_open_tables Yes Both No
Com_show_plugins Yes Both No
Com_show_privileges Yes Both No
Com_show_processlist Yes Both No
Com_show_slave_hosts Yes Both No
Com_show_slave_status Yes Both No
Com_show_status Yes Both No
Com_show_storage_engines Yes Both No
Com_show_tables Yes Both No
Com_show_triggers Yes Both No
Com_show_variables Yes Both No
Com_show_warnings Yes Both No
Com_slave_start Yes Both No
Com_slave_stop Yes Both No
Com_stmt_close Yes Both No
Com_stmt_execute Yes Both No
Com_stmt_fetch Yes Both No
Com_stmt_prepare Yes Both No
Com_stmt_reset Yes Both No
Com_stmt_send_long_data Yes Both No
Com_truncate Yes Both No
Com_unlock_tables Yes Both No
Com_update Yes Both No
Com_update_multi Yes Both No
Com_xa_commit Yes Both No
Com_xa_end Yes Both No
Com_xa_prepare Yes Both No
Com_xa_recover Yes Both No
Com_xa_rollback Yes Both No
Com_xa_start Yes Both No
completion_typeYes Yes Yes Both Yes
Compression Yes Session No
concurrent_insertYes Yes Yes Global Yes
connect_timeoutYes Yes Yes Global Yes
Connections Yes Global No
console Yes Yes
core-file Yes Yes
Created_tmp_disk_tables Yes Both No
Created_tmp_files Yes Global No
Created_tmp_tables Yes Both No
datadir Yes Yes Yes Global No
date_format Yes Both No
datetime_format Yes Both No
debug Yes Yes Yes Both Yes
default-character-setYes Yes
default-storage-engineYes Yes Yes Both Yes
default-table-typeYes Yes
default-time-zoneYes Yes
default_week_formatYes Yes Yes Both Yes
defaults-extra-fileYes
defaults-file Yes
defaults-group-suffixYes
delay-key-writeYes Yes Global Yes
- _Variable_: Yes Global Yes
delay_key_write
Delayed_errors Yes Global No
delayed_insert_limitYes Yes Yes Global Yes
Delayed_insert_threads Yes Global No
delayed_insert_timeoutYes Yes Yes Global Yes
delayed_queue_sizeYes Yes Yes Global Yes
Delayed_writes Yes Global No
des-key-file Yes Yes
disconnect-slave-event-countYes Yes
div_precision_incrementYes Yes Yes Both Yes
enable-locking Yes Yes
enable-named-pipeYes Yes
- _Variable_:
named_pipe
enable-pstack Yes Yes
engine-condition-pushdownYes Yes Both Yes
- _Variable_: Yes Both Yes
engine_condition_pushdown
error_count Yes Session No
exit-info Yes Yes
expire_logs_daysYes Yes Yes Global Yes
external-lockingYes Yes
- _Variable_:
skip_external_locking
flush Yes Yes Yes Global Yes
Flush_commands Yes Global No
flush_time Yes Yes Yes Global Yes
foreign_key_checks Yes Session Yes
ft_boolean_syntaxYes Yes Yes Global Yes
ft_max_word_lenYes Yes Yes Global No
ft_min_word_lenYes Yes Yes Global No
ft_query_expansion_limitYes Yes Yes Global No
ft_stopword_fileYes Yes Yes Global No
gdb Yes Yes
group_concat_max_lenYes Yes Yes Both Yes
Handler_commit Yes Both No
Handler_delete Yes Both No
Handler_discover Yes Both No
Handler_prepare Yes Both No
Handler_read_first Yes Both No
Handler_read_key Yes Both No
Handler_read_next Yes Both No
Handler_read_prev Yes Both No
Handler_read_rnd Yes Both No
Handler_read_rnd_next Yes Both No
Handler_rollback Yes Both No
Handler_savepoint Yes Both No
Handler_savepoint_rollback Yes Both No
Handler_update Yes Both No
Handler_write Yes Both No
have_archive Yes Global No
have_bdb Yes Global No
have_blackhole_engine Yes Global No
have_compress Yes Global No
have_crypt Yes Global No
have_csv Yes Global No
have_example_engine Yes Global No
have_federated_engine Yes Global No
have_geometry Yes Global No
have_innodb Yes Global No
have_isam Yes Global No
have_merge_engine Yes Global No
have_ndbcluster Yes Global No
have_openssl Yes Global No
have_query_cache Yes Global No
have_raid Yes Global No
have_rtree_keys Yes Global No
have_ssl Yes Global No
have_symlink Yes Global No
help Yes Yes
hostname Yes Global No
identity Yes Session Yes
init_connect Yes Yes Yes Global Yes
init-file Yes Yes Global No
- _Variable_: Yes Global No
init_file
init-rpl-role Yes Yes
init_slave Yes Yes Yes Global Yes
innodb Yes Yes
innodb_adaptive_hash_indexYes Yes Yes Global No
innodb_additional_mem_pool_sizeYes Yes Yes Global No
innodb_autoextend_incrementYes Yes Yes Global Yes
innodb_buffer_pool_awe_mem_mbYes Yes Yes Global No
Innodb_buffer_pool_pages_data Yes Global No
Innodb_buffer_pool_pages_dirty Yes Global No
Innodb_buffer_pool_pages_flushed Yes Global No
Innodb_buffer_pool_pages_free Yes Global No
Innodb_buffer_pool_pages_latched Yes Global No
Innodb_buffer_pool_pages_misc Yes Global No
Innodb_buffer_pool_pages_total Yes Global No
Innodb_buffer_pool_read_ahead_rnd Yes Global No
Innodb_buffer_pool_read_ahead_seq Yes Global No
Innodb_buffer_pool_read_requests Yes Global No
Innodb_buffer_pool_reads Yes Global No
innodb_buffer_pool_sizeYes Yes Yes Global No
Innodb_buffer_pool_wait_free Yes Global No
Innodb_buffer_pool_write_requests Yes Global No
innodb_checksumsYes Yes Yes Global No
innodb_commit_concurrencyYes Yes Yes Global Yes
innodb_concurrency_ticketsYes Yes Yes Global Yes
innodb_data_file_pathYes Yes Yes Global No
Innodb_data_fsyncs Yes Global No
innodb_data_home_dirYes Yes Yes Global No
Innodb_data_pending_fsyncs Yes Global No
Innodb_data_pending_reads Yes Global No
Innodb_data_pending_writes Yes Global No
Innodb_data_read Yes Global No
Innodb_data_reads Yes Global No
Innodb_data_writes Yes Global No
Innodb_data_written Yes Global No
Innodb_dblwr_pages_written Yes Global No
Innodb_dblwr_writes Yes Global No
innodb_doublewriteYes Yes Yes Global No
innodb_fast_shutdownYes Yes Yes Global Yes
innodb_file_io_threadsYes Yes Yes Global No
innodb_file_per_tableYes Yes Yes Global No
innodb_flush_log_at_trx_commitYes Yes Yes Global Yes
innodb_flush_methodYes Yes Yes Global No
innodb_force_recoveryYes Yes Yes Global No
innodb_lock_wait_timeoutYes Yes Yes Global No
innodb_locks_unsafe_for_binlogYes Yes Yes Global No
innodb_log_arch_dirYes Yes Yes Global No
innodb_log_archiveYes Yes Yes Global No
innodb_log_buffer_sizeYes Yes Yes Global No
innodb_log_file_sizeYes Yes Yes Global No
innodb_log_files_in_groupYes Yes Yes Global No
innodb_log_group_home_dirYes Yes Yes Global No
Innodb_log_waits Yes Global No
Innodb_log_write_requests Yes Global No
Innodb_log_writes Yes Global No
innodb_max_dirty_pages_pctYes Yes Yes Global Yes
innodb_max_purge_lagYes Yes Yes Global Yes
innodb_mirrored_log_groupsYes Yes Yes Global No
innodb_open_filesYes Yes Yes Global No
Innodb_os_log_fsyncs Yes Global No
Innodb_os_log_pending_fsyncs Yes Global No
Innodb_os_log_pending_writes Yes Global No
Innodb_os_log_written Yes Global No
Innodb_page_size Yes Global No
Innodb_pages_created Yes Global No
Innodb_pages_read Yes Global No
Innodb_pages_written Yes Global No
innodb_rollback_on_timeoutYes Yes Yes Global No
Innodb_row_lock_current_waits Yes Global No
Innodb_row_lock_time Yes Global No
Innodb_row_lock_time_avg Yes Global No
Innodb_row_lock_time_max Yes Global No
Innodb_row_lock_waits Yes Global No
Innodb_rows_deleted Yes Global No
Innodb_rows_inserted Yes Global No
Innodb_rows_read Yes Global No
Innodb_rows_updated Yes Global No
innodb-safe-binlogYes Yes
innodb-status-fileYes Yes
innodb_support_xaYes Yes Yes Both Yes
innodb_sync_spin_loopsYes Yes Yes Global Yes
innodb_table_locksYes Yes Yes Both Yes
innodb_thread_concurrencyYes Yes Yes Global Yes
innodb_thread_sleep_delayYes Yes Yes Global Yes
innodb_use_legacy_cardinality_algorithmYes Yes Yes Global Yes
insert_id Yes Session Yes
interactive_timeoutYes Yes Yes Both Yes
join_buffer_sizeYes Yes Yes Both Yes
keep_files_on_createYes Yes Yes Both Yes
Key_blocks_not_flushed Yes Global No
Key_blocks_unused Yes Global No
Key_blocks_used Yes Global No
key_buffer_sizeYes Yes Yes Global Yes
key_cache_age_thresholdYes Yes Yes Global Yes
key_cache_block_sizeYes Yes Yes Global Yes
key_cache_division_limitYes Yes Yes Global Yes
Key_read_requests Yes Global No
Key_reads Yes Global No
Key_write_requests Yes Global No
Key_writes Yes Global No
language Yes Yes Yes Global No
large_files_support Yes Global No
large_page_size Yes Global No
large-pages Yes Yes Global No
- _Variable_: Yes Global No
large_pages
last_insert_id Yes Session Yes
Last_query_cost Yes Session No
lc_time_names Yes Both Yes
license Yes Global No
local_infile Yes Global Yes
local-infile Yes Yes
- _Variable_:
local_infile
locked_in_memory Yes Global No
log Yes Yes Yes Global No
log_bin Yes Global No
log-bin Yes Yes Yes Global No
log-bin-index Yes Yes
log-bin-trust-function-creatorsYes Yes Global Yes
- _Variable_: Yes Global Yes
log_bin_trust_function_creators
log-bin-trust-routine-creatorsYes Yes Global Yes
- _Variable_: Yes Global Yes
log_bin_trust_routine_creators
log-error Yes Yes Global No
- _Variable_: Yes Global No
log_error
log-isam Yes Yes
log-queries-not-using-indexesYes Yes Global Yes
- _Variable_: Yes Global Yes
log_queries_not_using_indexes
log-short-formatYes Yes
log-slave-updatesYes Yes Global No
- _Variable_: Yes Global No
log_slave_updates
log-slow-admin-statementsYes Yes
log-slow-queriesYes Yes Global No
- _Variable_: Yes Global No
log_slow_queries
log-tc Yes Yes
log-tc-size Yes Yes
log-warnings Yes Yes Both Yes
- _Variable_: Yes Both Yes
log_warnings
long_query_timeYes Yes Yes Both Yes
low-priority-updatesYes Yes Both Yes
- _Variable_: Yes Both Yes
low_priority_updates
lower_case_file_systemYes Yes Yes Global No
lower_case_table_namesYes Yes Yes Global No
master-connect-retryYes Yes
master-host Yes Yes
master-info-fileYes Yes
master-passwordYes Yes
master-port Yes Yes
master-retry-countYes Yes
master-ssl Yes Yes
master-ssl-ca Yes Yes
master-ssl-capathYes Yes
master-ssl-certYes Yes
master-ssl-cipherYes Yes
master-ssl-key Yes Yes
master-user Yes Yes
max_allowed_packetYes Yes Yes Global Yes
max_binlog_cache_sizeYes Yes Yes Global Yes
max-binlog-dump-eventsYes Yes
max_binlog_sizeYes Yes Yes Global Yes
max_connect_errorsYes Yes Yes Global Yes
max_connectionsYes Yes Yes Global Yes
max_delayed_threadsYes Yes Yes Both Yes
max_error_countYes Yes Yes Both Yes
max_heap_table_sizeYes Yes Yes Both Yes
max_insert_delayed_threads Yes Both Yes
max_join_size Yes Yes Yes Both Yes
max_length_for_sort_dataYes Yes Yes Both Yes
max_prepared_stmt_countYes Yes Yes Global Yes
max_relay_log_sizeYes Yes Yes Global Yes
max_seeks_for_keyYes Yes Yes Both Yes
max_sort_lengthYes Yes Yes Both Yes
max_sp_recursion_depthYes Yes Yes Both Yes
max_tmp_tables Yes Yes Yes Both Yes
Max_used_connections Yes Global No
max_user_connectionsYes Yes Yes Both Yes
max_write_lock_countYes Yes Yes Global Yes
memlock Yes Yes Yes Global No
merge Yes Yes
multi_range_countYes Yes Yes Both Yes
myisam-block-sizeYes Yes
myisam_data_pointer_sizeYes Yes Yes Global Yes
myisam_max_extra_sort_file_sizeYes Yes Yes Global No
myisam_max_sort_file_sizeYes Yes Yes Global Yes
myisam_mmap_sizeYes Yes Yes Global No
myisam-recover Yes Yes
- _Variable_:
myisam_recover_options
myisam_recover_options Yes Global No
myisam_repair_threadsYes Yes Yes Both Yes
myisam_sort_buffer_sizeYes Yes Yes Both Yes
myisam_stats_methodYes Yes Yes Both Yes
named_pipe Yes Global No
ndb_autoincrement_prefetch_szYes Yes Yes Both Yes
ndb_cache_check_timeYes Yes Yes Global Yes
Ndb_cluster_node_id Yes Both No
Ndb_config_from_host Yes Both No
Ndb_config_from_port Yes Both No
ndb_force_send Yes Yes Yes Both Yes
ndb_index_stat_cache_entriesYes Yes
ndb_index_stat_enableYes Yes
ndb_index_stat_update_freqYes Yes
ndb-mgmd-host Yes Yes
ndb-nodeid Yes Yes Yes Global No
ndb_optimized_node_selectionYes Yes
ndb_report_thresh_binlog_epoch_slipYes Yes
ndb_report_thresh_binlog_mem_usageYes Yes
ndb_use_exact_count Yes Both Yes
ndb_use_transactionsYes Yes Yes Both Yes
ndbcluster Yes Yes
- _Variable_:
have_ndbcluster
net_buffer_lengthYes Yes Yes Both Yes
net_read_timeoutYes Yes Yes Both Yes
net_retry_countYes Yes Yes Both Yes
net_write_timeoutYes Yes Yes Both Yes
new Yes Yes Yes Both Yes
no-defaults Yes
Not_flushed_delayed_rows Yes Global No
old-passwords Yes Yes Both Yes
- _Variable_: Yes Both Yes
old_passwords
old-style-user-limitsYes Yes
one-thread Yes Yes
Open_files Yes Global No
open-files-limitYes Yes Global No
- _Variable_: Yes Global No
open_files_limit
Open_streams Yes Global No
Open_tables Yes Both No
Opened_tables Yes Both No
optimizer_prune_levelYes Yes Yes Both Yes
optimizer_search_depthYes Yes Yes Both Yes
pid-file Yes Yes Global No
- _Variable_: Yes Global No
pid_file
plugin_dir Yes Yes Yes Global No
port Yes Yes Yes Global No
port-open-timeoutYes Yes
preload_buffer_sizeYes Yes Yes Both Yes
Prepared_stmt_count Yes Global No
prepared_stmt_count Yes Global No
print-defaults Yes
profiling Yes Session Yes
profiling_history_size Yes Both Yes
protocol_version Yes Global No
pseudo_thread_id Yes Session Yes
Qcache_free_blocks Yes Global No
Qcache_free_memory Yes Global No
Qcache_hits Yes Global No
Qcache_inserts Yes Global No
Qcache_lowmem_prunes Yes Global No
Qcache_not_cached Yes Global No
Qcache_queries_in_cache Yes Global No
Qcache_total_blocks Yes Global No
Queries Yes Both No
query_alloc_block_sizeYes Yes Yes Both Yes
query_cache_limitYes Yes Yes Global Yes
query_cache_min_res_unitYes Yes Yes Global Yes
query_cache_sizeYes Yes Yes Global Yes
query_cache_typeYes Yes Yes Both Yes
query_cache_wlock_invalidateYes Yes Yes Both Yes
query_prealloc_sizeYes Yes Yes Both Yes
Questions Yes Both No
rand_seed1 Yes Session Yes
rand_seed2 Yes Session Yes
range_alloc_block_sizeYes Yes Yes Both Yes
read_buffer_sizeYes Yes Yes Both Yes
read_only Yes Yes Yes Global Yes
read_rnd_buffer_sizeYes Yes Yes Both Yes
relay-log Yes Yes
relay-log-indexYes Yes Both No
- _Variable_: Yes Both No
relay_log_index
relay-log-info-fileYes Yes
- _Variable_:
relay_log_info_file
relay_log_purgeYes Yes Yes Global Yes
relay_log_space_limitYes Yes Yes Global No
replicate-do-dbYes Yes
replicate-do-tableYes Yes
replicate-ignore-dbYes Yes
replicate-ignore-tableYes Yes
replicate-rewrite-dbYes Yes
replicate-same-server-idYes Yes
replicate-wild-do-tableYes Yes
replicate-wild-ignore-tableYes Yes
report-host Yes Yes Global No
- _Variable_: Yes Global No
report_host
report-passwordYes Yes Global No
- _Variable_: Yes Global No
report_password
report-port Yes Yes Global No
- _Variable_: Yes Global No
report_port
report-user Yes Yes Global No
- _Variable_: Yes Global No
report_user
rpl_recovery_rank Yes Global Yes
Rpl_status Yes Global No
safe-mode Yes Yes
safe-show-databaseYes Yes Yes Global Yes
safe-user-createYes Yes
safemalloc-mem-limitYes Yes
secure-auth Yes Yes Global Yes
- _Variable_: Yes Global Yes
secure_auth
secure-file-privYes Yes Global No
- _Variable_: Yes Global No
secure_file_priv
Select_full_join Yes Both No
Select_full_range_join Yes Both No
Select_range Yes Both No
Select_range_check Yes Both No
Select_scan Yes Both No
server-id Yes Yes Global Yes
- _Variable_: Yes Global Yes
server_id
set-variable Yes Yes
shared_memory Yes Global No
shared_memory_base_name Yes Global No
show-slave-auth-infoYes Yes
skip-bdb Yes Yes
skip-character-set-client-handshakeYes Yes
skip-concurrent-insertYes Yes
- _Variable_:
concurrent_insert
skip-external-lockingYes Yes Global No
- _Variable_: Yes Global No
skip_external_locking
skip-grant-tablesYes Yes
skip-host-cacheYes Yes
skip-locking Yes Yes
skip-log-warningsYes
skip-merge Yes Yes
- _Variable_:
skip-name-resolveYes Yes Global No
- _Variable_: Yes Global No
skip_name_resolve
skip-networkingYes Yes Global No
- _Variable_: Yes Global No
skip_networking
skip-new Yes Yes
skip-safemallocYes Yes
skip-show-databaseYes Yes Global No
- _Variable_: Yes Global No
skip_show_database
skip-slave-startYes Yes
skip-ssl Yes Yes
skip-stack-traceYes Yes
skip-symbolic-linksYes
skip-symlink Yes Yes
skip-sync-bdb-logsYes Yes Yes Global No
skip-thread-priorityYes Yes
slave_compressed_protocolYes Yes Yes Global Yes
slave-load-tmpdirYes Yes Global No
- _Variable_: Yes Global No
slave_load_tmpdir
slave-net-timeoutYes Yes Global Yes
- _Variable_: Yes Global Yes
slave_net_timeout
Slave_open_temp_tables Yes Global No
Slave_retried_transactions Yes Global No
Slave_running Yes Global No
slave-skip-errorsYes Yes Global No
- _Variable_: Yes Global No
slave_skip_errors
slave_transaction_retriesYes Yes Yes Global Yes
Slow_launch_threads Yes Both No
slow_launch_timeYes Yes Yes Global Yes
Slow_queries Yes Both No
socket Yes Yes Yes Global No
sort_buffer_sizeYes Yes Yes Both Yes
Sort_merge_passes Yes Both No
Sort_range Yes Both No
Sort_rows Yes Both No
Sort_scan Yes Both No
sporadic-binlog-dump-failYes Yes
sql_auto_is_null Yes Session Yes
sql_big_selects Yes Session Yes
sql_big_tables Yes Session Yes
sql_buffer_result Yes Session Yes
sql_log_bin Yes Session Yes
sql_log_off Yes Session Yes
sql_log_update Yes Session Yes
sql_low_priority_updates Yes Both Yes
sql_max_join_size Yes Both Yes
sql-mode Yes Yes Both Yes
- _Variable_: Yes Both Yes
sql_mode
sql_notes Yes Session Yes
sql_quote_show_create Yes Session Yes
sql_safe_updates Yes Session Yes
sql_select_limit Yes Both Yes
sql_slave_skip_counter Yes Global Yes
sql_warnings Yes Session Yes
ssl Yes Yes
Ssl_accept_renegotiates Yes Global No
Ssl_accepts Yes Global No
ssl-ca Yes Yes Global No
- _Variable_: Yes Global No
ssl_ca
Ssl_callback_cache_hits Yes Global No
ssl-capath Yes Yes Global No
- _Variable_: Yes Global No
ssl_capath
ssl-cert Yes Yes Global No
- _Variable_: Yes Global No
ssl_cert
ssl-cipher Yes Yes Global No
- _Variable_: Yes Global No
ssl_cipher
Ssl_cipher Yes Both No
Ssl_cipher_list Yes Both No
Ssl_client_connects Yes Global No
Ssl_connect_renegotiates Yes Global No
Ssl_ctx_verify_depth Yes Global No
Ssl_ctx_verify_mode Yes Global No
Ssl_default_timeout Yes Both No
Ssl_finished_accepts Yes Global No
Ssl_finished_connects Yes Global No
ssl-key Yes Yes Global No
- _Variable_: Yes Global No
ssl_key
Ssl_session_cache_hits Yes Global No
Ssl_session_cache_misses Yes Global No
Ssl_session_cache_mode Yes Global No
Ssl_session_cache_overflows Yes Global No
Ssl_session_cache_size Yes Global No
Ssl_session_cache_timeouts Yes Global No
Ssl_sessions_reused Yes Both No
Ssl_used_session_cache_entries Yes Global No
Ssl_verify_depth Yes Both No
Ssl_verify_mode Yes Both No
Ssl_version Yes Both No
standalone Yes Yes
storage_engine Yes Both Yes
symbolic-links Yes Yes
sync-bdb-logs Yes Yes Global No
- _Variable_: Yes Global No
sync_bdb_logs
sync_binlog Yes Yes Yes Global Yes
sync_frm Yes Yes Yes Global Yes
sysdate-is-now Yes Yes
system_time_zone Yes Global No
table_cache Yes Yes Yes Global Yes
table_lock_wait_timeoutYes Yes Yes Global Yes
Table_locks_immediate Yes Global No
Table_locks_waited Yes Global No
table_type Yes Both Yes
tc-heuristic-recoverYes Yes
Tc_log_max_pages_used Yes Global No
Tc_log_page_size Yes Global No
Tc_log_page_waits Yes Global No
temp-pool Yes Yes
thread_cache_sizeYes Yes Yes Global Yes
thread_concurrencyYes Yes Yes Global No
thread_stack Yes Yes Yes Global No
Threads_cached Yes Global No
Threads_connected Yes Global No
Threads_created Yes Global No
Threads_running Yes Global No
time_format Yes Both No
time_zone Yes Yes Yes Both Yes
timed_mutexes Yes Yes Yes Global Yes
timestamp Yes Session Yes
tmp_table_size Yes Yes Yes Both Yes
tmpdir Yes Yes Yes Global No
transaction_alloc_block_sizeYes Yes Yes Both Yes
transaction-isolationYes Yes
transaction_prealloc_sizeYes Yes Yes Both Yes
tx_isolation Yes Both Yes
unique_checks Yes Session Yes
updatable_views_with_limitYes Yes Yes Both Yes
Uptime Yes Global No
Uptime_since_flush_status Yes Global No
user Yes Yes
verbose Yes Yes
version Yes Global No
version_comment Yes Global No
version_compile_machine Yes Global No
version_compile_os Yes Global No
wait_timeout Yes Yes Yes Both Yes
warning_count Yes Session No
warnings Yes Yes

File: manual.info, Node: server-options, Next: server-system-variables, Prev: mysqld-option-tables, Up: mysqld-server

6.1.2 Server Command Options
----------------------------

When you start the *Note `mysqld': mysqld. server, you can specify
program options using any of the methods described in *Note
program-options::. The most common methods are to provide options in an
option file or on the command line. However, in most cases it is
desirable to make sure that the server uses the same options each time
it runs. The best way to ensure this is to list them in an option file.
See *Note option-files::.

*Note `mysqld': mysqld. reads options from the `[mysqld]' and `[server]'
groups. *Note `mysqld_safe': mysqld-safe. reads options from the
`[mysqld]', `[server]', `[mysqld_safe]', and `[safe_mysqld]' groups.
*Note `mysql.server': mysql-server. reads options from the `[mysqld]'
and `[mysql.server]' groups.

An embedded MySQL server usually reads options from the `[server]',
`[embedded]', and `[XXXXX_SERVER]' groups, where XXXXX is the name of
the application into which the server is embedded.

*Note `mysqld': mysqld. accepts many command options. For a brief
summary, execute *Note `mysqld --help': mysqld. To see the full list,
use *Note `mysqld --verbose --help': mysqld.

The following list shows some of the most common server options.
Additional options are described in other sections:

* Options that affect security: See *Note privileges-options::.

* SSL-related options: See *Note ssl-options::.

* Binary log control options: See *Note
replication-options-binary-log::.

* Replication-related options: See *Note replication-options::.

* Options specific to particular storage engines: See *Note
myisam-start::, *Note bdb-start::, *Note innodb-parameters::, and
*Note mysql-cluster-program-options-mysqld::.

You can also set the values of server system variables by using
variable names as options, as described at the end of this section.

Some options control the size of buffers or caches. For a given buffer,
the server might need to allocate internal data structures. These
structures typically are allocated from the total memory allocated to
the buffer, and the amount of space required might be platform
dependent. This means that when you assign a value to an option that
controls a buffer size, the amount of space actually available might
differ from the value assigned. In some cases, the amount might be less
than the value assigned. It is also possible that the server will
adjust a value upward. For example, if you assign a value of 0 to an
option for which the minimal value is 1024, the server will set the
value to 1024.

Values for buffer sizes, lengths, and stack sizes are given in bytes
unless otherwise specified.

Some options take file name values. Unless otherwise specified, the
default file location is the data directory if the value is a relative
path name. To specify the location explicitly, use an absolute path
name. Suppose that the data directory is `/var/mysql/data'. If a
file-valued option is given as a relative path name, it will be located
under `/var/mysql/data'. If the value is an absolute path name, its
location is as given by the path name.

* `--help', `-?'

Options for help *Command-Line `-?'
Format*
** `--help'
*Option-File Format* `help'

Display a short help message and exit. Use both the `--verbose' and
`--help' options to see the full message.

* `--allow-suspicious-udfs'

Options for allow-suspicious-udfs *Version Introduced* 5.0.3
*Command-Line `--allow-suspicious-udfs'
Format*
*Option-File Format* `allow-suspicious-udfs'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

This option controls whether user-defined functions that have only
an `xxx' symbol for the main function can be loaded. By default,
the option is off and only UDFs that have at least one auxiliary
symbol can be loaded; this prevents attempts at loading functions
from shared object files other than those containing legitimate
UDFs. This option was added in version 5.0.3. See *Note
udf-security::.

* `--ansi'

Options for ansi *Command-Line `--ansi'
Format*
** `-a'
*Option-File Format* `ansi'

Use standard (ANSI) SQL syntax instead of MySQL syntax. For more
precise control over the server SQL mode, use the `--sql-mode'
option instead. See *Note ansi-mode::, and *Note server-sql-mode::.

* `--basedir=PATH', `-b PATH'

Options for basedir *Command-Line `--basedir=path'
Format*
** `-b'
*Option-File Format* `basedir'
*Option Sets Yes,
Variable* `basedir'
*Variable Name* `basedir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The path to the MySQL installation directory. All paths are
usually resolved relative to this directory.

* `--big-tables'

Options for big-tables *Command-Line `--big-tables'
Format*
*Option-File Format* `big-tables'
*Option Sets Yes,
Variable* `big_tables'
*Variable Name* `big-tables'
*Variable Scope* Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'

Enable large result sets by saving all temporary sets in files.
This option prevents most `table full' errors, but also slows down
queries for which in-memory tables would suffice. Since MySQL
3.23.2, the server is able to handle large result sets
automatically by using memory for small temporary tables and
switching to disk tables where necessary.

* `--bind-address=IP'

Options for bind-address *Command-Line `--bind-address=name'
Format*
*Option-File Format* `bind-address=name'
*Variable Name* `bind-address'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `string'
*Default* `0.0.0.0'
*Range* `0.0.0.0-255.255.255.255'

The IP address to bind to. Only one address can be selected. If
this option is specified multiple times, the last address given is
used.

If no address or `0.0.0.0' is specified, the server listens on all
interfaces.

* `--bootstrap'

Options for bootstrap *Command-Line `--bootstrap'
Format*
*Option-File Format* `bootstrap'

This option is used by the *Note `mysql_install_db':
mysql-install-db. script to create the MySQL privilege tables
without having to start a full MySQL server.

This option is unavailable if MySQL was configured with the
`--disable-grant-options' option. See *Note
source-configuration-options::.

* `--character-sets-dir=PATH'

Options for character-sets-dir *Command-Line `--character-sets-dir=path'
Format*
*Option-File Format* `character-sets-dir=path'
*Option Sets Yes,
Variable* `character_sets_dir'
*Variable Name* `character-sets-dir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `directory
name'

The directory where character sets are installed. See *Note
charset-configuration::.

* `--character-set-client-handshake'

Options for character-set-client-handshake *Command-Line `--character-set-client-handshake'
Format*
*Option-File Format* `character-set-client-handshake'
*Permitted
Values
*
*Type* `boolean'
*Default* `TRUE'

Do not ignore character set information sent by the client. To
ignore client information and use the default server character
set, use `--skip-character-set-client-handshake'; this makes MySQL
behave like MySQL 4.0.

* `--character-set-filesystem=CHARSET_NAME'

Options for character-set-filesystem *Version Introduced* 5.0.19
*Command-Line `--character-set-filesystem=name'
Format*
*Option-File Format* `character-set-filesystem'
*Option Sets Yes,
Variable* `character_set_filesystem'
*Variable Name* `character_set_filesystem'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

The file system character set. This option sets the
`character_set_filesystem' system variable. It was added in MySQL
5.0.19.

* `--character-set-server=CHARSET_NAME', `-C CHARSET_NAME'

Options for character-set-server *Command-Line `--character-set-server'
Format*
*Option-File Format* `character-set-server'
*Option Sets Yes,
Variable* `character_set_server'
*Variable Name* `character_set_server'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

Use CHARSET_NAME as the default server character set. See *Note
charset-configuration::. If you use this option to specify a
nondefault character set, you should also use `--collation-server'
to specify the collation.

* `--chroot=PATH', `-r PATH'

Options for chroot *Command-Line `--chroot=name'
Format*
** `-r
name'
*Option-File Format* `chroot'
*Permitted
Values
*
*Type* `file
name'

Put the *Note `mysqld': mysqld. server in a closed environment
during startup by using the `chroot()' system call. This is a
recommended security measure. Note that use of this option
somewhat limits *Note `LOAD DATA INFILE': load-data. and *Note
`SELECT ... INTO OUTFILE': select.

* `--collation-server=COLLATION_NAME'

Options for collation-server *Command-Line `--collation-server'
Format*
*Option-File Format* `collation-server'
*Option Sets Yes,
Variable* `collation_server'
*Variable Name* `collation_server'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

Use COLLATION_NAME as the default server collation. See *Note
charset-configuration::.

* `--console'

Options for console *Command-Line `--console'
Format*
*Option-File Format* `console'
*Platform Specific* windows

(Windows only.) Write error log messages to `stderr' and `stdout'
even if `--log-error' is specified. *Note `mysqld': mysqld. does
not close the console window if this option is used.

* `--core-file'

Options for core-file *Command-Line `--core-file'
Format*
*Option-File Format* `core-file'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Write a core file if *Note `mysqld': mysqld. dies. The name and
location of the core file is system dependent. On Linux, a core
file named `core.PID' is written to the current working directory
of the process, which for *Note `mysqld': mysqld. is the data
directory. PID represents the process ID of the server process.
On Mac OS X, a core file named `core.PID' is written to the
`/cores' directory. On Solaris, use the `coreadm' command to
specify where to write the core file and how to name it.

For some systems, to get a core file you must also specify the
`--core-file-size' option to *Note `mysqld_safe': mysqld-safe. See
*Note mysqld-safe::. On some systems, such as Solaris, you do not
get a core file if you are also using the `--user' option. There
might be additional restrictions or limitations. For example, it
might be necessary to execute `ulimit -c unlimited' before
starting the server. Consult your system documentation.

* `--datadir=PATH', `-h PATH'

Options for datadir *Command-Line `--datadir=path'
Format*
** `-h'
*Option-File Format* `datadir'
*Option Sets Yes,
Variable* `datadir'
*Variable Name* `datadir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The path to the data directory.

* `--debug[=DEBUG_OPTIONS]', `-# [DEBUG_OPTIONS]'

Options for debug *Command-Line `--debug[=debug_options]'
Format*
*Option-File Format* `debug'
*Variable Name* `debug'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'
*Default* `'d:t:o,/tmp/mysqld.trace''

If MySQL is configured with `--with-debug', you can use this
option to get a trace file of what *Note `mysqld': mysqld. is
doing. A typical DEBUG_OPTIONS string is `'d:t:o,FILE_NAME''. The
default is `'d:t:i:o,mysqld.trace''. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* `--default-character-set=CHARSET_NAME'

Options for default-character-set *Version Deprecated* 5.0
*Command-Line `--default-character-set=name'
Format*
** `-C
name'
*Option-File Format* `default-character-set=name'
*Deprecated* 5.0
*Permitted
Values
*
*Type* `string'

Use CHARSET_NAME as the default character set. This option is
deprecated in favor of `--character-set-server'. See *Note
charset-configuration::. `--default-character-set' is removed in
MySQL 5.5.

* `--default-collation=COLLATION_NAME'

Options for default-collation *Command-Line `--default-collation=name'
Format*
*Option-File Format* `default-collation=name'
*Deprecated* 4.1.3
*Permitted
Values
*
*Type* `string'

Use COLLATION_NAME as the default collation. This option is
deprecated in favor of `--collation-server'. See *Note
charset-configuration::. `--default-collation' is removed in
MySQL 5.5.

* `--default-storage-engine=TYPE'

Options for default-storage-engine *Command-Line `--default-storage-engine=name'
Format*
*Option-File Format* `default-storage-engine'
*Variable Name* `default-storage-engine'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes

Set the default storage engine (table type) for tables. See *Note
storage-engines::.

* `--default-table-type=TYPE'

Options for default-table-type *Version Deprecated* 5.0
*Command-Line `--default-table-type=name'
Format*
*Option-File Format* `default-table-type'
*Deprecated* 5.0,
by
`default-storage-engine'
*Permitted
Values
*
*Type* `string'

This option is a deprecated synonym for `--default-storage-engine'.

* `--default-time-zone=TIMEZONE'

Options for default-time-zone *Command-Line `--default-time-zone=name'
Format*
*Option-File Format* `default-time-zone'
*Permitted
Values
*
*Type* `string'

Set the default server time zone. This option sets the global
`time_zone' system variable. If this option is not given, the
default time zone is the same as the system time zone (given by
the value of the `system_time_zone' system variable.

* `--delay-key-write[={OFF|ON|ALL}]'

Options for delay-key-write *Command-Line `--delay-key-write[=name]'
Format*
*Option-File Format* `delay-key-write'
*Option Sets Yes,
Variable* `delay_key_write'
*Variable Name* `delay-key-write'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `enumeration'
*Default* `ON'
*Valid Values* `ON',
`OFF',
`ALL'

Specify how to use delayed key writes. Delayed key writing causes
key buffers not to be flushed between writes for `MyISAM' tables.
`OFF' disables delayed key writes. `ON' enables delayed key writes
for those tables that were created with the `DELAY_KEY_WRITE'
option. `ALL' delays key writes for all `MyISAM' tables. See
*Note server-parameters::, and *Note myisam-start::.

*Note*:

If you set this variable to `ALL', you should not use `MyISAM'
tables from within another program (such as another MySQL server or
*Note `myisamchk': myisamchk.) when the tables are in use. Doing
so leads to index corruption.

* `--des-key-file=FILE_NAME'

Options for des-key-file *Command-Line `--des-key-file=file_name'
Format*
*Option-File Format* `des-key-file=file_name'

Read the default DES keys from this file. These keys are used by
the `DES_ENCRYPT()' and `DES_DECRYPT()' functions.

* `--enable-named-pipe'

Options for enable-named-pipe *Command-Line `--enable-named-pipe'
Format*
*Option-File Format* `enable-named-pipe'
*Option Sets Yes,
Variable* `named_pipe'
*Platform Specific* windows

Enable support for named pipes. This option can be used only with
the *Note `mysqld-nt': mysqld. and *Note `mysqld-debug': mysqld.
servers that support named-pipe connections.

* `--enable-pstack'

Options for enable-pstack *Command-Line `--enable-pstack'
Format*
*Option-File Format* `enable-pstack'
*Deprecated* 5.1.54
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Print a symbolic stack trace on failure. This capability is
available only on Intel Linux systems, and only if MySQL was
configured with the `--with-pstack' option.

* `--engine-condition-pushdown={ON|OFF}'

Options for engine-condition-pushdown *Version Introduced* 5.0.3
*Command-Line `--engine-condition-pushdown'
Format*
*Option-File Format* `engine-condition-pushdown'
*Option Sets Yes,
Variable* `engine_condition_pushdown'
*Variable Name* `engine_condition_pushdown'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Deprecated* 5.5.3,
by
`optimizer_switch'
*Permitted
Values
(>=
5.0.3)*
*Type* `boolean'
*Default* `OFF'

Sets the `engine_condition_pushdown' system variable. For more
information, see *Note condition-pushdown-optimization::.

This variable was added in MySQL 5.0.3.

* `--exit-info[=FLAGS]', `-T [FLAGS]'

Options for exit-info *Command-Line `--exit-info[=flags]'
Format*
** `-T
[flags]'
*Option-File Format* `exit-info'
*Permitted
Values
*
*Type* `numeric'

This is a bit mask of different flags that you can use for
debugging the *Note `mysqld': mysqld. server. Do not use this
option unless you know _exactly_ what it does!

* `--external-locking'

Options for external-locking *Command-Line `--external-locking'
Format*
*Option-File Format* `external-locking'
*Option Sets Yes,
Variable* `skip_external_locking'
*Disabled by* `skip-external-locking'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Enable external locking (system locking), which is disabled by
default as of MySQL 4.0. Note that if you use this option on a
system on which `lockd' does not fully work (such as Linux), it is
easy for *Note `mysqld': mysqld. to deadlock. This option
previously was named `--enable-locking'.

External locking affects only *Note `MyISAM':
myisam-storage-engine. table access. For more information,
including conditions under which it can and cannot be used, see
*Note external-locking::.

* `--flush'

Options for flush *Command-Line `--flush'
Format*
*Option-File Format* `flush'
*Variable Name* `flush'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'
*Default* `OFF'

Flush (synchronize) all changes to disk after each SQL statement.
Normally, MySQL does a write of all changes to disk only after
each SQL statement and lets the operating system handle the
synchronizing to disk. See *Note crashing::.

* `--gdb'

Options for gdb *Command-Line `--gdb'
Format*
*Option-File Format* `gdb'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Install an interrupt handler for `SIGINT' (needed to stop *Note
`mysqld': mysqld. with `^C' to set breakpoints) and disable stack
tracing and core file handling. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* `--init-file=FILE_NAME'

Options for init-file *Command-Line `--init-file=file_name'
Format*
*Option-File Format* `init-file=file_name'
*Option Sets Yes,
Variable* `init_file'
*Variable Name* `init_file'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

Read SQL statements from this file at startup. Each statement must
be on a single line and should not include comments.

This option is unavailable if MySQL was configured with the
`--disable-grant-options' option. See *Note
source-configuration-options::.

* `--innodb-safe-binlog'

Options for innodb-safe-binlog *Version Removed* 5.0.3
*Version Deprecated* 5.0.3
*Command-Line `--innodb-safe-binlog'
Format*
*Option-File Format* `innodb-safe-binlog'
*Deprecated* 5.0.3
*Permitted
Values
*
*Type* `boolean'

If this option is given, then after a crash recovery by `InnoDB',
*Note `mysqld': mysqld. truncates the binary log after the last
not-rolled-back transaction in the log. The option also causes
`InnoDB' to print an error if the binary log is smaller or shorter
than it should be. See *Note binary-log::. This option was removed
in MySQL 5.0.3, having been made obsolete by the introduction of
XA transaction support.

* `--innodb-XXX'

The `InnoDB' options are listed in *Note innodb-parameters::.

* `--language=LANG_NAME, -L LANG_NAME'

Options for language *Command-Line `--language=name'
Format*
** `-L'
*Option-File Format* `language'
*Option Sets Yes,
Variable* `language'
*Variable Name* `language'
*Variable Scope* Global
*Dynamic Variable* No
*Deprecated* 5.5.0,
by
`lc-messages-dir'
*Permitted
Values
*
*Type* `directory
name'
*Default* `/usr/local/mysql/share/mysql/english/'

The language to use for error messages. LANG_NAME can be given as
the language name or as the full path name to the directory where
the language files are installed. See *Note
error-message-language::.

* `--large-pages'

Options for large-pages *Version Introduced* 5.0.3
*Command-Line `--large-pages'
Format*
*Option-File Format* `large-pages'
*Option Sets Yes,
Variable* `large_pages'
*Variable Name* `large_pages'
*Variable Scope* Global
*Dynamic Variable* No
*Platform Specific* linux
*Permitted
Values
*
*Type* (linux) `boolean'
*Default* `FALSE'

Some hardware/operating system architectures support memory pages
greater than the default (usually 4KB). The actual implementation
of this support depends on the underlying hardware and operating
system. Applications that perform a lot of memory accesses may
obtain performance improvements by using large pages due to
reduced Translation Lookaside Buffer (TLB) misses.

Currently, MySQL supports only the Linux implementation of large
page support (which is called HugeTLB in Linux). See *Note
large-page-support::.

`--large-pages' is disabled by default. It was added in MySQL
5.0.3.

* `--log[=FILE_NAME]', `-l [FILE_NAME]'

Options for log *Command-Line `--log[=name]'
Format*
** `-l'
*Option-File Format* `log'
*Option Sets Yes,
Variable* `log'
*Variable Name* `log'
*Variable Scope* Global
*Dynamic Variable* No
*Deprecated* 5.1.29,
by
`general-log'
*Permitted
Values
*
*Type* `string'
*Default* `OFF'

Log connections and SQL statements received from clients to this
file. See *Note query-log::. If you omit the file name, MySQL uses
`HOST_NAME.log' as the file name.

* `--log-error[=FILE_NAME]'

Options for log-error *Command-Line `--log-error[=name]'
Format*
*Option-File Format* `log-error'
*Option Sets Yes,
Variable* `log_error'
*Variable Name* `log_error'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

Log errors and startup messages to this file. See *Note
error-log::. If you omit the file name, MySQL uses `HOST_NAME.err'.
If the file name has no extension, the server adds an extension of
`.err'.

* `--log-isam[=FILE_NAME]'

Options for log-isam *Command-Line `--log-isam[=name]'
Format*
*Option-File Format* `log-isam'
*Permitted
Values
*
*Type* `file
name'

Log all `MyISAM' changes to this file (used only when debugging
`MyISAM').

* `--log-long-format'

Options for log-long-format *Command-Line `--log-long-format'
Format*
** `-0'
*Option-File Format* `log-long-format'
*Deprecated* 4.1

Log extra information to the update log, binary update log, and
slow query log, if they have been activated. For example, the user
name and timestamp are logged for all queries. This option is
deprecated, as it now represents the default logging behavior.
(See the description for `--log-short-format'.) The
`--log-queries-not-using-indexes' option is available for the
purpose of logging queries that do not use indexes to the slow
query log. `--log-long-format' is removed in MySQL 5.5.

* `--log-queries-not-using-indexes'

Options for log-queries-not-using-indexes *Command-Line `--log-queries-not-using-indexes'
Format*
*Option-File Format* `log-queries-not-using-indexes'
*Option Sets Yes,
Variable* `log_queries_not_using_indexes'
*Variable Name* `log_queries_not_using_indexes'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'

If you are using this option with the slow query log enabled,
queries that are expected to retrieve all rows are logged. See
*Note slow-query-log::. This option does not necessarily mean that
no index is used. For example, a query that uses a full index scan
uses an index but would be logged because the index would not
limit the number of rows.

* `--log-short-format'

Options for log-short-format *Command-Line `--log-short-format'
Format*
*Option-File Format* `log-short-format'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Originally intended to log less information to the update log,
binary log and slow query log, if they have been activated.
However, this option is not operational.

* `--log-slow-admin-statements'

Options for log-slow-admin-statements *Command-Line `--log-slow-admin-statements'
Format*
*Option-File Format* `log-slow-admin-statements'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Log slow administrative statements such as *Note `OPTIMIZE TABLE':
optimize-table, *Note `ANALYZE TABLE': analyze-table, and *Note
`ALTER TABLE': alter-table. to the slow query log.

* `--log-slow-queries[=FILE_NAME]'

Options for log-slow-queries *Command-Line `--log-slow-queries[=name]'
Format*
*Option-File Format* `log-slow-queries'
*Option Sets Yes,
Variable* `log_slow_queries'
*Variable Name* `log_slow_queries'
*Variable Scope* Global
*Dynamic Variable* No
*Deprecated* 5.1.29,
by
`slow-query-log'
*Permitted
Values
*
*Type* `boolean'

Log all queries that have taken more than `long_query_time'
seconds to execute to this file. See *Note slow-query-log::. See
the descriptions of the `--log-long-format' and
`--log-short-format' options for details.

* `--log-tc=FILE_NAME'

Options for log-tc *Version Introduced* 5.0.3
*Command-Line `--log-tc=name'
Format*
*Option-File Format* `log-tc'
*Permitted
Values
*
*Type* `file
name'
*Default* `tc.log'

The name of the memory-mapped transaction coordinator log file
(for XA transactions that affect multiple storage engines when the
binary log is disabled). The default name is `tc.log'. The file is
created under the data directory if not given as a full path name.
Currently, this option is unused. Added in MySQL 5.0.3.

* `--log-tc-size=SIZE'

Options for log-tc-size *Version Introduced* 5.0.3
*Command-Line `--log-tc-size=#'
Format*
*Option-File Format* `log-tc-size'
*Permitted
Values
*
*Platform Bit Size* `32'
*Type* `numeric'
*Default* `24576'
*Max Value* `4294967295'
*Permitted
Values
*
*Platform Bit Size* `64'
*Type* `numeric'
*Default* `24576'
*Max Value* `18446744073709547520'

The size in bytes of the memory-mapped transaction coordinator
log. The default size is 24KB. Added in MySQL 5.0.3.

* `--log-warnings[=LEVEL]', `-W [LEVEL]'

Options for log-warnings *Command-Line `--log-warnings[=#]'
Format*
** `-W
[#]'
*Option-File Format* `log-warnings'
*Option Sets Yes,
Variable* `log_warnings'
*Variable Name* `log_warnings'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Disabled by* `skip-log-warnings'
*Permitted
Values
*
*Platform Bit Size* `64'
*Type* `numeric'
*Default* `1'
*Range* `0-18446744073709547520'

Print out warnings such as `Aborted connection...' to the error
log. Enabling this option is recommended, for example, if you use
replication (you get more information about what is happening,
such as messages about network failures and reconnections). This
option is enabled (1) by default, and the default LEVEL value if
omitted is 1. To disable this option, use `--log-warnings=0'. If
the value is greater than 1, aborted connections are written to the
error log. See *Note communication-errors::.

If a slave server was started with `--log-warnings' enabled, the
slave prints messages to the error log to provide information
about its status, such as the binary log and relay log coordinates
where it starts its job, when it is switching to another relay
log, when it reconnects after a disconnect, and so forth.

* `--low-priority-updates'

Options for low-priority-updates *Command-Line `--low-priority-updates'
Format*
*Option-File Format* `low-priority-updates'
*Option Sets Yes,
Variable* `low_priority_updates'
*Variable Name* `low_priority_updates'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Give table-modifying operations (*Note `INSERT': insert, *Note
`REPLACE': replace, *Note `DELETE': delete, *Note `UPDATE':
update.) lower priority than selects. This can also be done using
`{INSERT | REPLACE | DELETE | UPDATE} LOW_PRIORITY ...' to lower
the priority of only one query, or by `SET LOW_PRIORITY_UPDATES=1'
to change the priority in one thread. This affects only storage
engines that use only table-level locking (`MyISAM', `MEMORY',
`MERGE'). See *Note table-locking::.

* `--memlock'

Options for memlock *Command-Line `--memlock'
Format*
*Option-File Format* `memlock'
*Variable Name* `locked_in_memory'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Lock the *Note `mysqld': mysqld. process in memory. This option
might help if you have a problem where the operating system is
causing *Note `mysqld': mysqld. to swap to disk.

`--memlock' works on systems that support the `mlockall()' system
call; this includes Solaris as well as most Linux distributions
that use a 2.4 or newer kernel. On Linux systems, you can tell
whether or not `mlockall()' (and thus this option) is supported by
checking to see whether or not it is defined in the system
`mman.h' file, like this:

shell> grep mlockall /usr/include/sys/mman.h

If `mlockall()' is supported, you should see in the output of the
previous command something like the following:

extern int mlockall (int __flags) __THROW;

*Important*:

Using this option requires that you run the server as `root',
which, for reasons of security, is normally not a good idea. See
*Note changing-mysql-user::.

You must not try to use this option on a system that does not
support the `mlockall()' system call; if you do so, *Note
`mysqld': mysqld. will very likely crash as soon as you try to
start it.

* `--myisam-block-size=N'

Options for myisam-block-size *Command-Line `--myisam-block-size=#'
Format*
*Option-File Format* `myisam-block-size'
*Permitted
Values
*
*Type* `numeric'
*Default* `1024'
*Range* `1024-16384'

The block size to be used for `MyISAM' index pages.

* `--myisam-recover[=OPTION[,OPTION]...]]'

Options for myisam-recover *Command-Line `--myisam-recover[=name]'
Format*
*Option-File Format* `myisam-recover'
*Option Sets Yes,
Variable* `myisam_recover_options'
*Permitted
Values
*
*Type* `enumeration'
*Default* `OFF'
*Valid Values* `DEFAULT',
`BACKUP',
`FORCE',
`QUICK'

Set the `MyISAM' storage engine recovery mode. The option value is
any combination of the values of `DEFAULT', `BACKUP', `FORCE', or
`QUICK'. If you specify multiple values, separate them by commas.
Specifying the option with no argument is the same as specifying
`DEFAULT', and specifying with an explicit value of `""' disables
recovery (same as not giving the option). If recovery is enabled,
each time *Note `mysqld': mysqld. opens a `MyISAM' table, it
checks whether the table is marked as crashed or was not closed
properly. (The last option works only if you are running with
external locking disabled.) If this is the case, *Note `mysqld':
mysqld. runs a check on the table. If the table was corrupted,
*Note `mysqld': mysqld. attempts to repair it.

The following options affect how the repair works.

Option Description
`DEFAULT' Recovery without backup, forcing, or quick
checking.
`BACKUP' If the data file was changed during recovery,
save a backup of the `TBL_NAME.MYD' file as
`TBL_NAME-DATETIME.BAK'.
`FORCE' Run recovery even if we would lose more than
one row from the `.MYD' file.
`QUICK' Do not check the rows in the table if there
are not any delete blocks.

Before the server automatically repairs a table, it writes a note
about the repair to the error log. If you want to be able to
recover from most problems without user intervention, you should
use the options `BACKUP,FORCE'. This forces a repair of a table
even if some rows would be deleted, but it keeps the old data file
as a backup so that you can later examine what happened.

See *Note myisam-start::.

* `--old-passwords'

Options for old-passwords *Command-Line `--old_passwords'
Format*
*Option-File Format* `old-passwords'
*Option Sets Yes,
Variable* `old_passwords'
*Variable Name* `old_passwords'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Force the server to generate short (pre-4.1) password hashes for
new passwords. This is useful for compatibility when the server
must support older client programs. See *Note password-hashing::.

* `--old-style-user-limits'

Options for old-style-user-limits *Version Introduced* 5.0.3
*Command-Line `--old-style-user-limits'
Format*
*Option-File Format* `old-style-user-limits'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Enable old-style user limits. (Before MySQL 5.0.3, account
resource limits were counted separately for each host from which a
user connected rather than per account row in the `user' table.)
See *Note user-resources::. This option was added in MySQL 5.0.3.

* `--one-thread'

Options for one-thread *Command-Line `--one-thread'
Format*
*Option-File Format* `one-thread'

Only use one thread (for debugging under Linux). This option is
available only if the server is built with debugging enabled. See
MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* `--open-files-limit=COUNT'

Options for open-files-limit *Command-Line `--open-files-limit=#'
Format*
*Option-File Format* `open-files-limit'
*Option Sets Yes,
Variable* `open_files_limit'
*Variable Name* `open_files_limit'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Default* `0'
*Range* `0-65535'

Changes the number of file descriptors available to *Note
`mysqld': mysqld. You should try increasing the value of this
option if *Note `mysqld': mysqld. gives you the error `Too many
open files'. *Note `mysqld': mysqld. uses the option value to
reserve descriptors with `setrlimit()'. If the requested number of
file descriptors cannot be allocated, *Note `mysqld': mysqld.
writes a warning to the error log.

*Note `mysqld': mysqld. may attempt to allocate more than the
requested number of descriptors (if they are available), using the
values of `max_connections' and `table_cache' to estimate whether
more descriptors will be needed.

* `--pid-file=PATH'

Options for pid-file *Command-Line `--pid-file=file_name'
Format*
*Option-File Format* `pid-file=file_name'
*Option Sets Yes,
Variable* `pid_file'
*Variable Name* `pid_file'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The path name of the process ID file. The server creates the file
in the data directory unless an absolute path name is given to
specify a different directory. This file is used by other programs
such as *Note `mysqld_safe': mysqld-safe. to determine the
server's process ID.

* `--port=PORT_NUM', `-P PORT_NUM'

Options for port *Command-Line `--port=#'
Format*
** `-P'
*Option-File Format* `port'
*Option Sets Yes,
Variable* `port'
*Variable Name* `port'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Default* `3306'

The port number to use when listening for TCP/IP connections. The
port number must be 1024 or higher unless the server is started by
the `root' system user.

* `--port-open-timeout=NUM'

Options for port-open-timeout *Version Introduced* 5.0.19
*Command-Line `--port-open-timeout=#'
Format*
*Option-File Format* `port-open-timeout'
*Permitted
Values
*
*Type* `numeric'
*Default* `0'

On some systems, when the server is stopped, the TCP/IP port might
not become available immediately. If the server is restarted
quickly afterward, its attempt to reopen the port can fail. This
option indicates how many seconds the server should wait for the
TCP/IP port to become free if it cannot be opened. The default is
not to wait. This option was added in MySQL 5.0.19.

* `--safe-mode'

Options for safe-mode *Version Deprecated* 5.0
*Command-Line `--safe-mode'
Format*
*Option-File Format* `safe-mode'
*Deprecated* 5.0

Skip some optimization stages.

* `--safe-show-database'

Options for safe-show-database *Command-Line `--safe-show-database'(until
Format* 4.1.1)
*Option-File Format* `safe-show-database'
*Variable Name* `safe_show_database'
*Variable Scope* Global
*Dynamic Variable* Yes
*Deprecated* 4.0.2
*Permitted
Values
*
*Type* `boolean'

This option is deprecated and does not do anything because there
is a *Note `SHOW DATABASES': show-databases. privilege that can
be used to control access to database names on a per-account
basis. See *Note privileges-provided::. `--safe-show-database' is
removed in MySQL 5.5.

* `--safe-user-create'

Options for safe-user-create *Command-Line `--safe-user-create'
Format*
*Option-File Format* `safe-user-create'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

If this option is enabled, a user cannot create new MySQL users by
using the *Note `GRANT': grant. statement unless the user has the
`INSERT' privilege for the `mysql.user' table or any column in the
table. If you want a user to have the ability to create new users
that have those privileges that the user has the right to grant,
you should grant the user the following privilege:

GRANT INSERT(user) ON mysql.user TO 'USER_NAME'@'HOST_NAME';

This ensures that the user cannot change any privilege columns
directly, but has to use the *Note `GRANT': grant. statement to
give privileges to other users.

* `--secure-auth'

Options for secure-auth *Command-Line `--secure-auth'
Format*
*Option-File Format* `secure-auth'
*Option Sets Yes,
Variable* `secure_auth'
*Variable Name* `secure_auth'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

Disallow authentication by clients that attempt to use accounts
that have old (pre-4.1) passwords.

* `--secure-file-priv=PATH'

Options for secure-file-priv *Version Introduced* 5.0.38
*Command-Line `--secure-file-priv=path'
Format*
*Option-File Format* `secure-file-priv=path'
*Option Sets Yes,
Variable* `secure_file_priv'
*Variable Name* `secure-file-priv'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `string'

This option limits the effect of the `LOAD_FILE()' function and the
*Note `LOAD DATA': load-data. and *Note `SELECT ... INTO OUTFILE':
select. statements to work only with files in the specified
directory.

This option was added in MySQL 5.0.38.

* `--shared-memory'

Enable shared-memory connections by local clients. This option is
available only on Windows.

* `--shared-memory-base-name=NAME'

The name of shared memory to use for shared-memory connections.
This option is available only on Windows. The default name is
`MYSQL'. The name is case sensitive.

* `--skip-bdb'

Disable the `BDB' storage engine. This saves memory and might
speed up some operations. Do not use this option if you require
`BDB' tables.

* `--skip-concurrent-insert'

Turn off the ability to select and insert at the same time on
`MyISAM' tables. (This is to be used only if you think you have
found a bug in this feature.) See *Note concurrent-inserts::.

* `--skip-external-locking'

Do not use external locking (system locking). This affects only
*Note `MyISAM': myisam-storage-engine. table access. For more
information, including conditions under which it can and cannot be
used, see *Note external-locking::.

External locking has been disabled by default since MySQL 4.0.

* `--skip-grant-tables'

This option causes the server to start without using the privilege
system at all, which gives anyone with access to the server
_unrestricted access to all databases_. You can cause a running
server to start using the grant tables again by executing *Note
`mysqladmin flush-privileges': mysqladmin. or *Note `mysqladmin
reload': mysqladmin. command from a system shell, or by issuing a
MySQL *Note `FLUSH PRIVILEGES': flush. statement after connecting
to the server. This option also suppresses loading of
user-defined functions (UDFs).

This option is unavailable if MySQL was configured with the
`--disable-grant-options' option. See *Note
source-configuration-options::.

* `--skip-host-cache'

Do not use the internal host name cache for faster name-to-IP
resolution. Instead, query the DNS server every time a client
connects. See *Note dns::.

* `--skip-innodb'

Disable the `InnoDB' storage engine. In this case, the server will
not start if the default storage engine is set to *Note `InnoDB':
innodb-storage-engine. Use `--default-storage-engine' to set the
default to some other engine if necessary.

* `--skip-merge'

Disable the `MERGE' storage engine. This option was added in MySQL
5.0.24. It can be used if the following behavior is undesirable:
If a user has access to `MyISAM' table T, that user can create a
`MERGE' table M that accesses T. However, if the user's privileges
on T are subsequently revoked, the user can continue to access T
by doing so through M.

* `--skip-name-resolve'

Do not resolve host names when checking client connections. Use
only IP addresses. If you use this option, all `Host' column
values in the grant tables must be IP addresses or `localhost'. See
*Note dns::.

* `--skip-networking'

Do not listen for TCP/IP connections at all. All interaction with
*Note `mysqld': mysqld. must be made using named pipes or shared
memory (on Windows) or Unix socket files (on Unix). This option
is highly recommended for systems where only local clients are
permitted. See *Note dns::.

* `--ssl*'

Options that begin with `--ssl' specify whether to permit clients
to connect using SSL and indicate where to find SSL keys and
certificates. See *Note ssl-options::.

* `--standalone'

Options for standalone *Command-Line `--standalone'
Format*
*Option-File Format* `standalone'
*Platform Specific* windows

Instructs the MySQL server not to run as a service.

* `--symbolic-links', `--skip-symbolic-links'

Options for symbolic-links *Command-Line `--symbolic-links'
Format*
*Option-File Format* `symbolic-links'

Enable or disable symbolic link support. This option has different
effects on Windows and Unix:

* On Windows, enabling symbolic links enables you to establish
a symbolic link to a database directory by creating a
`DB_NAME.sym' file that contains the path to the real
directory. See *Note windows-symbolic-links::.

* On Unix, enabling symbolic links means that you can link a
`MyISAM' index file or data file to another directory with
the `INDEX DIRECTORY' or `DATA DIRECTORY' options of the
*Note `CREATE TABLE': create-table. statement. If you delete
or rename the table, the files that its symbolic links point
to also are deleted or renamed. See *Note
symbolic-links-to-tables::.

* `--skip-safemalloc'

Options for skip-safemalloc *Command-Line `--skip-safemalloc'
Format*
*Option-File Format* `skip-safemalloc'

If MySQL is configured with `--with-debug=full', all MySQL
programs check for memory overruns during each memory allocation
and memory freeing operation. This checking is very slow, so for
the server you can avoid it when you do not need it by using the
`--skip-safemalloc' option.

* `--skip-show-database'

Options for skip-show-database *Command-Line `--skip-show-database'
Format*
*Option-File Format* `skip-show-database'
*Option Sets Yes,
Variable* `skip_show_database'
*Variable Name* `skip_show_database'
*Variable Scope* Global
*Dynamic Variable* No

With this option, the *Note `SHOW DATABASES': show-databases.
statement is permitted only to users who have the `SHOW DATABASES'
privilege, and the statement displays all database names. Without
this option, *Note `SHOW DATABASES': show-databases. is permitted
to all users, but displays each database name only if the user has
the `SHOW DATABASES' privilege or some privilege for the database.
Note that _any_ global privilege is considered a privilege for the
database.

* `--skip-stack-trace'

Options for skip-stack-trace *Command-Line `--skip-stack-trace'
Format*
*Option-File Format* `skip-stack-trace'

Do not write stack traces. This option is useful when you are
running *Note `mysqld': mysqld. under a debugger. On some systems,
you also must use this option to get a core file. See MySQL
Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* `--skip-thread-priority'

Options for skip-thread-priority *Command-Line `--skip-thread-priority'
Format*
*Option-File Format* `skip-thread-priority'
*Deprecated* 5.1.29

Disable using thread priorities for faster response time.

*Note `mysqld': mysqld. makes a large number of invalid calls to
thread scheduling routines on Linux. These calls do not affect
performance noticeably but may be a source of `noise' for
debugging tools. For example, they can overwhelm other information
of more interest in kernel logs. To avoid these calls, start the
server with the `--skip-thread-priority' option.

* `--socket=PATH'

Options for socket *Command-Line `--socket=name'
Format*
*Option-File Format* `socket'
*Option Sets Yes,
Variable* `socket'
*Variable Name* `socket'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'
*Default* `/tmp/mysql.sock'

On Unix, this option specifies the Unix socket file to use when
listening for local connections. The default value is
`/tmp/mysql.sock'. If this option is given, the server creates the
file in the data directory unless an absolute path name is given
to specify a different directory. On Windows, the option
specifies the pipe name to use when listening for local
connections that use a named pipe. The default value is `MySQL'
(not case sensitive).

* `--sql-mode=VALUE[,VALUE[,VALUE...]]'

Options for sql-mode *Command-Line `--sql-mode=name'
Format*
*Option-File Format* `sql-mode'
*Option Sets Yes,
Variable* `sql_mode'
*Variable Name* `sql_mode'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `set'
*Default* `'''
*Valid Values* `ALLOW_INVALID_DATES',
`ANSI_QUOTES',
`ERROR_FOR_DIVISION_BY_ZERO',
`HIGH_NOT_PRECEDENCE',
`IGNORE_SPACE',
`NO_AUTO_CREATE_USER',
`NO_AUTO_VALUE_ON_ZERO',
`NO_BACKSLASH_ESCAPES',
`NO_DIR_IN_CREATE',
`NO_ENGINE_SUBSTITUTION',
`NO_FIELD_OPTIONS',
`NO_KEY_OPTIONS',
`NO_TABLE_OPTIONS',
`NO_UNSIGNED_SUBTRACTION',
`NO_ZERO_DATE',
`NO_ZERO_IN_DATE',
`ONLY_FULL_GROUP_BY',
`PAD_CHAR_TO_FULL_LENGTH',
`PIPES_AS_CONCAT',
`REAL_AS_FLOAT',
`STRICT_ALL_TABLES',
`STRICT_TRANS_TABLES'

Set the SQL mode. See *Note server-sql-mode::.

* `--sysdate-is-now'

Options for sysdate-is-now *Version Introduced* 5.0.20
*Command-Line `--sysdate-is-now'
Format*
*Option-File Format* `sysdate-is-now'
*Permitted
Values
*
*Type* `boolean'
*Default* `FALSE'

As of MySQL 5.0.12, `SYSDATE()' by default returns the time at
which it executes, not the time at which the statement in which it
occurs begins executing. This differs from the behavior of
`NOW()'. This option causes `SYSDATE()' to be an alias for
`NOW()'. For information about the implications for binary logging
and replication, see the description for `SYSDATE()' in *Note
date-and-time-functions:: and for `SET TIMESTAMP' in *Note
server-system-variables::.

This option was added in MySQL 5.0.20.

* `--tc-heuristic-recover={COMMIT|ROLLBACK}'

Options for tc-heuristic-recover *Version Introduced* 5.0.3
*Command-Line `--tc-heuristic-recover=name'
Format*
*Option-File Format* `tc-heuristic-recover'
*Permitted
Values
*
*Type* `enumeration'
*Valid Values* `COMMIT',
`RECOVER'

The type of decision to use in the heuristic recovery process.
Currently, this option is unused. Added in MySQL 5.0.3.

* `--temp-pool'

Options for temp-pool *Command-Line `--temp-pool'
Format*
*Option-File Format* `temp-pool'
*Permitted
Values
*
*Type* `boolean'
*Default* `TRUE'

This option causes most temporary files created by the server to
use a small set of names, rather than a unique name for each new
file. This works around a problem in the Linux kernel dealing with
creating many new files with different names. With the old
behavior, Linux seems to `leak' memory, because it is being
allocated to the directory entry cache rather than to the disk
cache.

* `--transaction-isolation=LEVEL'

Options for transaction-isolation *Command-Line `--transaction-isolation=name'
Format*
*Option-File Format* `transaction-isolation'
*Permitted
Values
*
*Type* `enumeration'
*Valid Values* `READ-UNCOMMITTED',
`READ-COMMITTED',
`REPEATABLE-READ',
`SERIALIZABLE'

Sets the default transaction isolation level. The `level' value
can be `READ-UNCOMMITTED', `READ-COMMITTED', `REPEATABLE-READ', or
`SERIALIZABLE'. See *Note set-transaction::.

* `--tmpdir=PATH', `-t PATH'

Options for tmpdir *Command-Line `--tmpdir=path'
Format*
** `-t'
*Option-File Format* `tmpdir'
*Option Sets Yes,
Variable* `tmpdir'
*Variable Name* `tmpdir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The path of the directory to use for creating temporary files. It
might be useful if your default `/tmp' directory resides on a
partition that is too small to hold temporary tables. This option
accepts several paths that are used in round-robin fashion. Paths
should be separated by colon characters (``:'') on Unix and
semicolon characters (``;'') on Windows, NetWare, and OS/2. If the
MySQL server is acting as a replication slave, you should not set
`--tmpdir' to point to a directory on a memory-based file system
or to a directory that is cleared when the server host restarts.
For more information about the storage location of temporary
files, see *Note temporary-files::. A replication slave needs some
of its temporary files to survive a machine restart so that it can
replicate temporary tables or *Note `LOAD DATA INFILE': load-data.
operations. If files in the temporary file directory are lost when
the server restarts, replication fails.

* `--user={USER_NAME|USER_ID}', `-u {USER_NAME|USER_ID}'

Options for user *Command-Line `--user=name'
Format*
** `-u
name'
*Option-File Format* `user'
*Permitted
Values
*
*Type* `string'

This option is _mandatory_ when starting *Note `mysqld': mysqld.
as `root'. The server changes its user ID during its startup
sequence, causing it to run as that particular user rather than as
`root'. See *Note security-guidelines::.

To avoid a possible security hole where a user adds a
`--user=root' option to a `my.cnf' file (thus causing the server to
run as `root'), *Note `mysqld': mysqld. uses only the first
`--user' option specified and produces a warning if there are
multiple `--user' options. Options in `/etc/my.cnf' and
`$MYSQL_HOME/my.cnf' are processed before command-line options, so
it is recommended that you put a `--user' option in `/etc/my.cnf'
and specify a value other than `root'. The option in `/etc/my.cnf'
is found before any other `--user' options, which ensures that the
server runs as a user other than `root', and that a warning
results if any other `--user' option is found.

* `--verbose', `-v'

Use this option with the `--help' option for detailed help.

* `--version', `-V'

Options for version *Variable Name* `version'
*Variable Scope* Global
*Dynamic Variable* No

Display version information and exit.

You can assign a value to a server system variable by using an option
of the form `--VAR_NAME=VALUE'. For example, `--key_buffer_size=32M'
sets the `key_buffer_size' variable to a value of 32MB.

Note that when you assign a value to a variable, MySQL might
automatically correct the value to stay within a given range, or adjust
the value to the closest permissible value if only certain values are
permitted.

If you want to restrict the maximum value to which a variable can be
set at runtime with *Note `SET': set-option, you can define this by
using the `--maximum-VAR_NAME=VALUE' command-line option.

It is also possible to set variables by using
`--set-variable=VAR_NAME=VALUE' or `-O VAR_NAME=VALUE' syntax. _This
syntax is deprecated_.

You can change the values of most system variables for a running server
with the *Note `SET': set-option. statement. See *Note set-option::.

*Note server-system-variables::, provides a full description for all
variables, and additional information for setting them at server
startup and runtime. *Note server-parameters::, includes information on
optimizing the server by tuning system variables.

File: manual.info, Node: server-system-variables, Next: using-system-variables, Prev: server-options, Up: mysqld-server

6.1.3 Server System Variables
-----------------------------

The MySQL server maintains many system variables that indicate how it
is configured. Each system variable has a default value. System
variables can be set at server startup using options on the command
line or in an option file. Most of them can be changed dynamically
while the server is running by means of the *Note `SET': set-option.
statement, which enables you to modify operation of the server without
having to stop and restart it. You can refer to system variable values
in expressions.

There are several ways to see the names and values of system variables:

* To see the values that a server will use based on its compiled-in
defaults and any option files that it reads, use this command:

mysqld --verbose --help

* To see the values that a server will use based on its compiled-in
defaults, ignoring the settings in any option files, use this
command:

mysqld --no-defaults --verbose --help

* To see the current values used by a running server, use the *Note
`SHOW VARIABLES': show-variables. statement.

This section provides a description of each system variable. Variables
with no version indicated are present in all MySQL 5.0 releases. For
historical information concerning their implementation, please see
http://www.mysql.com/products/enterprise//4.1/en/.

The following table lists all available system variables:

*System Variable Summary*

Name Cmd-Line Option file System Var Var Scope Dynamic
auto_increment_incrementYes Yes Yes Both Yes
auto_increment_offsetYes Yes Yes Both Yes
autocommit Yes Yes Yes Session Yes
automatic_sp_privileges Yes Global Yes
back_log Yes Yes Yes Global No
basedir Yes Yes Yes Global No
bdb_cache_size Yes Yes Yes Global No
bdb-home Yes Yes No
- _Variable_: Yes Global No
bdb_home
bdb-lock-detectYes Yes No
- _Variable_: Yes Global No
bdb_lock_detect
bdb_log_buffer_sizeYes Yes Yes Global No
bdb-logdir Yes Yes No
- _Variable_: Yes Global No
bdb_logdir
bdb_max_lock Yes Yes Yes Global No
bdb-shared-dataYes Yes No
- _Variable_: Yes Global No
bdb_shared_data
bdb-tmpdir Yes Yes No
- _Variable_: Yes Global No
bdb_tmpdir
big-tables Yes Yes Yes
- _Variable_: Yes Session Yes
big_tables
bind-address Yes Yes Yes Global No
binlog_cache_sizeYes Yes Yes Global Yes
bulk_insert_buffer_sizeYes Yes Yes Both Yes
character_set_client Yes Both Yes
character_set_connection Yes Both Yes
character_set_database Yes Both Yes
This option
is dynamic,
but only the
server should
set this
information.
You should
not set the
value of this
variable
manually.
character-set-filesystemYes Yes Yes
- _Variable_: Yes Both Yes
character_set_filesystem
character_set_results Yes Both Yes
character-set-serverYes Yes Yes
- _Variable_: Yes Both Yes
character_set_server
character_set_system Yes Global No
character-sets-dirYes Yes No
- _Variable_: Yes Global No
character_sets_dir
collation_connection Yes Both Yes
collation_database Yes Both Yes
This option
is dynamic,
but only the
server should
set this
information.
You should
not set the
value of this
variable
manually.
collation-serverYes Yes Yes
- _Variable_: Yes Both Yes
collation_server
completion_typeYes Yes Yes Both Yes
concurrent_insertYes Yes Yes Global Yes
connect_timeoutYes Yes Yes Global Yes
datadir Yes Yes Yes Global No
date_format Yes Both No
datetime_format Yes Both No
debug Yes Yes Yes Both Yes
default-storage-engineYes Yes Yes Both Yes
default_week_formatYes Yes Yes Both Yes
delay-key-writeYes Yes Yes
- _Variable_: Yes Global Yes
delay_key_write
delayed_insert_limitYes Yes Yes Global Yes
delayed_insert_timeoutYes Yes Yes Global Yes
delayed_queue_sizeYes Yes Yes Global Yes
div_precision_incrementYes Yes Yes Both Yes
engine-condition-pushdownYes Yes Yes
- _Variable_: Yes Both Yes
engine_condition_pushdown
error_count Yes Session No
expire_logs_daysYes Yes Yes Global Yes
flush Yes Yes Yes Global Yes
flush_time Yes Yes Yes Global Yes
foreign_key_checks Yes Session Yes
ft_boolean_syntaxYes Yes Yes Global Yes
ft_max_word_lenYes Yes Yes Global No
ft_min_word_lenYes Yes Yes Global No
ft_query_expansion_limitYes Yes Yes Global No
ft_stopword_fileYes Yes Yes Global No
group_concat_max_lenYes Yes Yes Both Yes
have_archive Yes Global No
have_bdb Yes Global No
have_blackhole_engine Yes Global No
have_compress Yes Global No
have_crypt Yes Global No
have_csv Yes Global No
have_example_engine Yes Global No
have_federated_engine Yes Global No
have_geometry Yes Global No
have_innodb Yes Global No
have_isam Yes Global No
have_merge_engine Yes Global No
have_ndbcluster Yes Global No
have_openssl Yes Global No
have_query_cache Yes Global No
have_raid Yes Global No
have_rtree_keys Yes Global No
have_ssl Yes Global No
have_symlink Yes Global No
hostname Yes Global No
identity Yes Session Yes
init_connect Yes Yes Yes Global Yes
init-file Yes Yes No
- _Variable_: Yes Global No
init_file
init_slave Yes Yes Yes Global Yes
innodb_adaptive_hash_indexYes Yes Yes Global No
innodb_additional_mem_pool_sizeYes Yes Yes Global No
innodb_autoextend_incrementYes Yes Yes Global Yes
innodb_buffer_pool_awe_mem_mbYes Yes Yes Global No
innodb_buffer_pool_sizeYes Yes Yes Global No
innodb_checksumsYes Yes Yes Global No
innodb_commit_concurrencyYes Yes Yes Global Yes
innodb_concurrency_ticketsYes Yes Yes Global Yes
innodb_data_file_pathYes Yes Yes Global No
innodb_data_home_dirYes Yes Yes Global No
innodb_doublewriteYes Yes Yes Global No
innodb_fast_shutdownYes Yes Yes Global Yes
innodb_file_io_threadsYes Yes Yes Global No
innodb_file_per_tableYes Yes Yes Global No
innodb_flush_log_at_trx_commitYes Yes Yes Global Yes
innodb_flush_methodYes Yes Yes Global No
innodb_force_recoveryYes Yes Yes Global No
innodb_lock_wait_timeoutYes Yes Yes Global No
innodb_locks_unsafe_for_binlogYes Yes Yes Global No
innodb_log_arch_dirYes Yes Yes Global No
innodb_log_archiveYes Yes Yes Global No
innodb_log_buffer_sizeYes Yes Yes Global No
innodb_log_file_sizeYes Yes Yes Global No
innodb_log_files_in_groupYes Yes Yes Global No
innodb_log_group_home_dirYes Yes Yes Global No
innodb_max_dirty_pages_pctYes Yes Yes Global Yes
innodb_max_purge_lagYes Yes Yes Global Yes
innodb_mirrored_log_groupsYes Yes Yes Global No
innodb_open_filesYes Yes Yes Global No
innodb_rollback_on_timeoutYes Yes Yes Global No
innodb_support_xaYes Yes Yes Both Yes
innodb_sync_spin_loopsYes Yes Yes Global Yes
innodb_table_locksYes Yes Yes Both Yes
innodb_thread_concurrencyYes Yes Yes Global Yes
innodb_thread_sleep_delayYes Yes Yes Global Yes
innodb_use_legacy_cardinality_algorithmYes Yes Yes Global Yes
insert_id Yes Session Yes
interactive_timeoutYes Yes Yes Both Yes
join_buffer_sizeYes Yes Yes Both Yes
keep_files_on_createYes Yes Yes Both Yes
key_buffer_sizeYes Yes Yes Global Yes
key_cache_age_thresholdYes Yes Yes Global Yes
key_cache_block_sizeYes Yes Yes Global Yes
key_cache_division_limitYes Yes Yes Global Yes
language Yes Yes Yes Global No
large_files_support Yes Global No
large_page_size Yes Global No
large-pages Yes Yes No
- _Variable_: Yes Global No
large_pages
last_insert_id Yes Session Yes
lc_time_names Yes Both Yes
license Yes Global No
local_infile Yes Global Yes
locked_in_memory Yes Global No
log Yes Yes Yes Global No
log_bin Yes Global No
log-bin Yes Yes Yes Global No
log-bin-trust-function-creatorsYes Yes Yes
- _Variable_: Yes Global Yes
log_bin_trust_function_creators
log-bin-trust-routine-creatorsYes Yes Yes
- _Variable_: Yes Global Yes
log_bin_trust_routine_creators
log-error Yes Yes No
- _Variable_: Yes Global No
log_error
log-queries-not-using-indexesYes Yes Yes
- _Variable_: Yes Global Yes
log_queries_not_using_indexes
log-slave-updatesYes Yes No
- _Variable_: Yes Global No
log_slave_updates
log-slow-queriesYes Yes No
- _Variable_: Yes Global No
log_slow_queries
log-warnings Yes Yes Yes
- _Variable_: Yes Both Yes
log_warnings
long_query_timeYes Yes Yes Both Yes
low-priority-updatesYes Yes Yes
- _Variable_: Yes Both Yes
low_priority_updates
lower_case_file_systemYes Yes Yes Global No
lower_case_table_namesYes Yes Yes Global No
max_allowed_packetYes Yes Yes Global Yes
max_binlog_cache_sizeYes Yes Yes Global Yes
max_binlog_sizeYes Yes Yes Global Yes
max_connect_errorsYes Yes Yes Global Yes
max_connectionsYes Yes Yes Global Yes
max_delayed_threadsYes Yes Yes Both Yes
max_error_countYes Yes Yes Both Yes
max_heap_table_sizeYes Yes Yes Both Yes
max_insert_delayed_threads Yes Both Yes
max_join_size Yes Yes Yes Both Yes
max_length_for_sort_dataYes Yes Yes Both Yes
max_prepared_stmt_countYes Yes Yes Global Yes
max_relay_log_sizeYes Yes Yes Global Yes
max_seeks_for_keyYes Yes Yes Both Yes
max_sort_lengthYes Yes Yes Both Yes
max_sp_recursion_depthYes Yes Yes Both Yes
max_tmp_tables Yes Yes Yes Both Yes
max_user_connectionsYes Yes Yes Both Yes
max_write_lock_countYes Yes Yes Global Yes
memlock Yes Yes Yes Global No
multi_range_countYes Yes Yes Both Yes
myisam_data_pointer_sizeYes Yes Yes Global Yes
myisam_max_extra_sort_file_sizeYes Yes Yes Global No
myisam_max_sort_file_sizeYes Yes Yes Global Yes
myisam_mmap_sizeYes Yes Yes Global No
myisam_recover_options Yes Global No
myisam_repair_threadsYes Yes Yes Both Yes
myisam_sort_buffer_sizeYes Yes Yes Both Yes
myisam_stats_methodYes Yes Yes Both Yes
named_pipe Yes Global No
ndb_autoincrement_prefetch_szYes Yes Yes Both Yes
ndb_cache_check_timeYes Yes Yes Global Yes
ndb_force_send Yes Yes Yes Both Yes
ndb_use_exact_count Yes Both Yes
ndb_use_transactionsYes Yes Yes Both Yes
net_buffer_lengthYes Yes Yes Both Yes
net_read_timeoutYes Yes Yes Both Yes
net_retry_countYes Yes Yes Both Yes
net_write_timeoutYes Yes Yes Both Yes
new Yes Yes Yes Both Yes
old-passwords Yes Yes Yes
- _Variable_: Yes Both Yes
old_passwords
open-files-limitYes Yes No
- _Variable_: Yes Global No
open_files_limit
optimizer_prune_levelYes Yes Yes Both Yes
optimizer_search_depthYes Yes Yes Both Yes
pid-file Yes Yes No
- _Variable_: Yes Global No
pid_file
plugin_dir Yes Yes Yes Global No
port Yes Yes Yes Global No
preload_buffer_sizeYes Yes Yes Both Yes
prepared_stmt_count Yes Global No
profiling Yes Session Yes
profiling_history_size Yes Both Yes
protocol_version Yes Global No
pseudo_thread_id Yes Session Yes
query_alloc_block_sizeYes Yes Yes Both Yes
query_cache_limitYes Yes Yes Global Yes
query_cache_min_res_unitYes Yes Yes Global Yes
query_cache_sizeYes Yes Yes Global Yes
query_cache_typeYes Yes Yes Both Yes
query_cache_wlock_invalidateYes Yes Yes Both Yes
query_prealloc_sizeYes Yes Yes Both Yes
rand_seed1 Yes Session Yes
rand_seed2 Yes Session Yes
range_alloc_block_sizeYes Yes Yes Both Yes
read_buffer_sizeYes Yes Yes Both Yes
read_only Yes Yes Yes Global Yes
read_rnd_buffer_sizeYes Yes Yes Both Yes
relay-log-indexYes Yes No
- _Variable_: Yes Both No
relay_log_index
relay_log_purgeYes Yes Yes Global Yes
relay_log_space_limitYes Yes Yes Global No
report-host Yes Yes No
- _Variable_: Yes Global No
report_host
report-passwordYes Yes No
- _Variable_: Yes Global No
report_password
report-port Yes Yes No
- _Variable_: Yes Global No
report_port
report-user Yes Yes No
- _Variable_: Yes Global No
report_user
rpl_recovery_rank Yes Global Yes
safe-show-databaseYes Yes Yes Global Yes
secure-auth Yes Yes Yes
- _Variable_: Yes Global Yes
secure_auth
secure-file-privYes Yes No
- _Variable_: Yes Global No
secure_file_priv
server-id Yes Yes Yes
- _Variable_: Yes Global Yes
server_id
shared_memory Yes Global No
shared_memory_base_name Yes Global No
skip-external-lockingYes Yes No
- _Variable_: Yes Global No
skip_external_locking
skip-name-resolveYes Yes No
- _Variable_: Yes Global No
skip_name_resolve
skip-networkingYes Yes No
- _Variable_: Yes Global No
skip_networking
skip-show-databaseYes Yes No
- _Variable_: Yes Global No
skip_show_database
skip-sync-bdb-logsYes Yes Yes Global No
slave_compressed_protocolYes Yes Yes Global Yes
slave-load-tmpdirYes Yes No
- _Variable_: Yes Global No
slave_load_tmpdir
slave-net-timeoutYes Yes Yes
- _Variable_: Yes Global Yes
slave_net_timeout
slave-skip-errorsYes Yes No
- _Variable_: Yes Global No
slave_skip_errors
slave_transaction_retriesYes Yes Yes Global Yes
slow_launch_timeYes Yes Yes Global Yes
socket Yes Yes Yes Global No
sort_buffer_sizeYes Yes Yes Both Yes
sql_auto_is_null Yes Session Yes
sql_big_selects Yes Session Yes
sql_big_tables Yes Session Yes
sql_buffer_result Yes Session Yes
sql_log_bin Yes Session Yes
sql_log_off Yes Session Yes
sql_log_update Yes Session Yes
sql_low_priority_updates Yes Both Yes
sql_max_join_size Yes Both Yes
sql-mode Yes Yes Yes
- _Variable_: Yes Both Yes
sql_mode
sql_notes Yes Session Yes
sql_quote_show_create Yes Session Yes
sql_safe_updates Yes Session Yes
sql_select_limit Yes Both Yes
sql_slave_skip_counter Yes Global Yes
sql_warnings Yes Session Yes
ssl-ca Yes Yes No
- _Variable_: Yes Global No
ssl_ca
ssl-capath Yes Yes No
- _Variable_: Yes Global No
ssl_capath
ssl-cert Yes Yes No
- _Variable_: Yes Global No
ssl_cert
ssl-cipher Yes Yes No
- _Variable_: Yes Global No
ssl_cipher
ssl-key Yes Yes No
- _Variable_: Yes Global No
ssl_key
storage_engine Yes Both Yes
sync-bdb-logs Yes Yes No
- _Variable_: Yes Global No
sync_bdb_logs
sync_binlog Yes Yes Yes Global Yes
sync_frm Yes Yes Yes Global Yes
system_time_zone Yes Global No
table_cache Yes Yes Yes Global Yes
table_lock_wait_timeoutYes Yes Yes Global Yes
table_type Yes Both Yes
thread_cache_sizeYes Yes Yes Global Yes
thread_concurrencyYes Yes Yes Global No
thread_stack Yes Yes Yes Global No
time_format Yes Both No
time_zone Yes Yes Yes Both Yes
timed_mutexes Yes Yes Yes Global Yes
timestamp Yes Session Yes
tmp_table_size Yes Yes Yes Both Yes
tmpdir Yes Yes Yes Global No
transaction_alloc_block_sizeYes Yes Yes Both Yes
transaction_prealloc_sizeYes Yes Yes Both Yes
tx_isolation Yes Both Yes
unique_checks Yes Session Yes
updatable_views_with_limitYes Yes Yes Both Yes
version Yes Global No
version_comment Yes Global No
version_compile_machine Yes Global No
version_compile_os Yes Global No
wait_timeout Yes Yes Yes Both Yes
warning_count Yes Session No

For additional system variable information, see these sections:

* *Note using-system-variables::, discusses the syntax for setting
and displaying system variable values.

* *Note dynamic-system-variables::, lists the variables that can be
set at runtime.

* Information on tuning system variables can be found in *Note
server-parameters::.

* *Note innodb-parameters::, lists `InnoDB' system variables.

* *Note mysql-cluster-system-variables::, lists system variables
which are specific to MySQL Cluster.

* For information on server system variables specific to
replication, see *Note replication-options::.

*Note*:

Some of the following variable descriptions refer to `enabling' or
`disabling' a variable. These variables can be enabled with the *Note
`SET': set-option. statement by setting them to `ON' or `1', or
disabled by setting them to `OFF' or `0'. However, to set such a
variable on the command line or in an option file, you must set it to
`1' or `0'; setting it to `ON' or `OFF' will not work. For example, on
the command line, `--delay_key_write=1' works but
`--delay_key_write=ON' does not.

Some system variables control the size of buffers or caches. For a
given buffer, the server might need to allocate internal data
structures. These structures typically are allocated from the total
memory allocated to the buffer, and the amount of space required might
be platform dependent. This means that when you assign a value to a
system variable that controls a buffer size, the amount of space
actually available might differ from the value assigned. In some cases,
the amount might be less than the value assigned. It is also possible
that the server will adjust a value upward. For example, if you assign
a value of 0 to a variable for which the minimal value is 1024, the
server will set the value to 1024.

Values for buffer sizes, lengths, and stack sizes are given in bytes
unless otherwise specified.

Some system variables take file name values. Unless otherwise
specified, the default file location is the data directory if the value
is a relative path name. To specify the location explicitly, use an
absolute path name. Suppose that the data directory is
`/var/mysql/data'. If a file-valued variable is given as a relative
path name, it will be located under `/var/mysql/data'. If the value is
an absolute path name, its location is as given by the path name.

* `autocommit'

Options for autocommit *Command-Line `--autocommit[=#]'
Format*
*Option-File Format* `autocommit'
*Option Sets Yes,
Variable* `autocommit'
*Variable Name* `autocommit'
*Variable Scope* Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'

The autocommit mode. If set to 1, all changes to a table take
effect immediately. If set to 0, you must use *Note `COMMIT':
commit. to accept a transaction or *Note `ROLLBACK': commit. to
cancel it. If `autocommit' is 0 and you change it to 1, MySQL
performs an automatic *Note `COMMIT': commit. of any open
transaction. Another way to begin a transaction is to use a *Note
`START TRANSACTION': commit. or *Note `BEGIN': commit. statement.
See *Note commit::.

By default, client connections begin with `autocommit' set to 1.
To cause clients to begin with a default of 0, set the server's
`init_connect' system variable:

SET GLOBAL init_connect='SET autocommit=0';

The `init_connect' variable can also be set on the command line or
in an option file. To set the variable as just shown using an
option file, include these lines:

[mysqld]
init_connect='SET autocommit=0'

The content of `init_connect' is not executed for users that have
the `SUPER' privilege.

* `automatic_sp_privileges'

Options for automatic_sp_privileges *Version Introduced* 5.0.3
*Variable Name* `automatic_sp_privileges'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `boolean'
*Default* `TRUE'

When this variable has a value of 1 (the default), the server
automatically grants the `EXECUTE' and `ALTER ROUTINE' privileges
to the creator of a stored routine, if the user cannot already
execute and alter or drop the routine. (The `ALTER ROUTINE'
privilege is required to drop the routine.) The server also
automatically drops those privileges from the creator when the
routine is dropped. If `automatic_sp_privileges' is 0, the server
does not automatically add or drop these privileges.

The creator of a routine is the account used to execute the
`CREATE' statement for it. This might not be the same as the
account named as the `DEFINER' in the routine definition.

See also *Note stored-routines-privileges::.

This variable was added in MySQL 5.0.3.

* `back_log'

Options for back_log *Command-Line `--back_log=#'
Format*
*Option-File Format* `back_log'
*Option Sets Yes,
Variable* `back_log'
*Variable Name* `back_log'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Default* `50'
*Range* `1-65535'

The number of outstanding connection requests MySQL can have.
This comes into play when the main MySQL thread gets very many
connection requests in a very short time. It then takes some time
(although very little) for the main thread to check the connection
and start a new thread. The `back_log' value indicates how many
requests can be stacked during this short time before MySQL
momentarily stops answering new requests. You need to increase
this only if you expect a large number of connections in a short
period of time.

In other words, this value is the size of the listen queue for
incoming TCP/IP connections. Your operating system has its own
limit on the size of this queue. The manual page for the Unix
`listen()' system call should have more details. Check your OS
documentation for the maximum value for this variable. `back_log'
cannot be set higher than your operating system limit.

* `basedir'

The MySQL installation base directory. This variable can be set
with the `--basedir' option. Relative path names for other
variables usually are resolved relative to the base directory.

* `bdb_cache_size'

Options for bdb_cache_size *Command-Line `--bdb_cache_size=#'
Format*
*Option-File Format* `bdb_cache_size'
*Option Sets Yes,
Variable* `bdb_cache_size'
*Variable Name* `bdb_cache_size'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Min Value* `20480
'

The size of the buffer that is allocated for caching indexes and
rows for `BDB' tables. If you do not use `BDB' tables, you should
start *Note `mysqld': mysqld. with `--skip-bdb' to not allocate
memory for this cache.

* `bdb_home'

Options for bdb-home *Command-Line `--bdb-home=name'
Format*
*Option-File Format* `bdb-home=name'
*Option Sets Yes,
Variable* `bdb_home'
*Variable Name* `bdb_home'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The base directory for `BDB' tables. This should be assigned the
same value as the `datadir' variable.

* `bdb_log_buffer_size'

Options for bdb_log_buffer_size *Command-Line `--bdb_log_buffer_size=#'
Format*
*Option-File Format* `bdb_log_buffer_size'
*Option Sets Yes,
Variable* `bdb_log_buffer_size'
*Variable Name* `bdb_log_buffer_size'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Range* `262144-4294967295'

The size of the buffer that is allocated for caching indexes and
rows for `BDB' tables. If you do not use `BDB' tables, you should
set this to 0 or start *Note `mysqld': mysqld. with `--skip-bdb'
to not allocate memory for this cache.

* `bdb_logdir'

Options for bdb-logdir *Command-Line `--bdb-logdir=file_name'
Format*
*Option-File Format* `bdb-logdir=file_name'
*Option Sets Yes,
Variable* `bdb_logdir'
*Variable Name* `bdb_logdir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The directory where the `BDB' storage engine writes its log files.
This variable can be set with the `--bdb-logdir' option.

* `bdb_max_lock'

Options for bdb_max_lock *Command-Line `--bdb_max_lock=#'
Format*
*Option-File Format* `bdb_max_lock'
*Option Sets Yes,
Variable* `bdb_max_lock'
*Variable Name* `bdb_max_lock'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `numeric'
*Default* `10000'

The maximum number of locks that can be active for a `BDB' table
(10,000 by default). You should increase this value if errors such
as the following occur when you perform long transactions or when
*Note `mysqld': mysqld. has to examine many rows to calculate a
query:

bdb: Lock table is out of available locks
Got error 12 from ...

* `bdb_shared_data'

Options for bdb-shared-data *Command-Line `--bdb-shared-data'
Format*
*Option-File Format* `bdb-shared-data'
*Option Sets Yes,
Variable* `bdb_shared_data'
*Variable Name* `bdb-shared-data'
*Variable Scope* Global
*Dynamic Variable* No

This is `ON' if you are using `--bdb-shared-data' to start
Berkeley DB in multi-process mode. (Do not use `DB_PRIVATE' when
initializing Berkeley DB.)

* `bdb_tmpdir'

Options for bdb-tmpdir *Command-Line `--bdb-tmpdir=path'
Format*
*Option-File Format* `bdb-tmpdir=path'
*Option Sets Yes,
Variable* `bdb_tmpdir'
*Variable Name* `bdb-tmpdir'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `file
name'

The `BDB' temporary file directory.

* `big_tables'

If set to 1, all temporary tables are stored on disk rather than
in memory. This is a little slower, but the error `The table
TBL_NAME is full' does not occur for *Note `SELECT': select.
operations that require a large temporary table. The default value
for a new connection is 0 (use in-memory temporary tables).
Normally, you should never need to set this variable, because
in-memory tables are automatically converted to disk-based tables
as required.

*Note*:

This variable was formerly named `sql_big_tables'.

* `binlog_cache_size'

Options for binlog_cache_size *Command-Line `--binlog_cache_size=#'
Format*
*Option-File Format* `binlog_cache_size'
*Option Sets Yes,
Variable* `binlog_cache_size'
*Variable Name* `binlog_cache_size'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
*
*Platform Bit Size* `32'
*Type* `numeric'
*Default* `32768'
*Range* `4096-4294967295'
*Permitted
Values
*
*Platform Bit Size* `64'
*Type* `numeric'
*Default* `32768'
*Range* `4096-18446744073709547520'

The size of the cache to hold the SQL statements for the binary
log during a transaction. A binary log cache is allocated for each
client if the server supports any transactional storage engines
and if the server has the binary log enabled (`--log-bin' option).
If you often use large, multiple-statement transactions, you can
increase this cache size to get better performance. The
`Binlog_cache_use' and `Binlog_cache_disk_use' status variables
can be useful for tuning the size of this variable. See *Note
binary-log::.

* `bulk_insert_buffer_size'

Options for bulk_insert_buffer_size *Command-Line `--bulk_insert_buffer_size=#'
Format*
*Option-File Format* `bulk_insert_buffer_size'
*Option Sets Yes,
Variable* `bulk_insert_buffer_size'
*Variable Name* `bulk_insert_buffer_size'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Platform Bit Size* `32'
*Type* `numeric'
*Default* `8388608'
*Range* `0-4294967295'
*Permitted
Values
*
*Platform Bit Size* `64'
*Type* `numeric'
*Default* `8388608'
*Range* `0-18446744073709547520'

`MyISAM' uses a special tree-like cache to make bulk inserts
faster for *Note `INSERT ... SELECT': insert-select, `INSERT ...
VALUES (...), (...), ...', and *Note `LOAD DATA INFILE':
load-data. when adding data to nonempty tables. This variable
limits the size of the cache tree in bytes per thread. Setting it
to 0 disables this optimization. The default value is 8MB.

* `character_set_client'

Options for character_set_client *Variable Name* `character_set_client'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

The character set for statements that arrive from the client. The
session value of this variable is set using the character set
requested by the client when the client connects to the server.
(Many clients support a `--default-character-set' option to enable
this character set to be specified explicitly. See also *Note
charset-connection::.) The global value of the variable is used to
set the session value in cases when the client-requested value is
unknown or not available, or the server is configured to ignore
client requests:

* The client is from a version of MySQL older than MySQL 4.1,
and thus does not request a character set.

* The client requests a character set not known to the server.
For example, a Japanese-enabled client requests `sjis' when
connecting to a server not configured with `sjis' support.

* *Note `mysqld': mysqld. was started with the
`--skip-character-set-client-handshake' option, which causes
it to ignore client character set configuration. This
reproduces MySQL 4.0 behavior and is useful should you wish
to upgrade the server without upgrading all the clients.

`ucs2' cannot be used as a client character set, which means that
it also does not work for `SET NAMES' or `SET CHARACTER SET'.

* `character_set_connection'

Options for character_set_connection *Variable Name* `character_set_connection'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

The character set used for literals that do not have a character
set introducer and for number-to-string conversion.

* `character_set_database'

Options for character_set_database *Variable Name* `character_set_database'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Footnote* This
option
is
dynamic,
but
only
the
server
should
set
this
information.
You
should
not
set
the
value
of
this
variable
manually.
*Permitted
Values
*
*Type* `string'

The character set used by the default database. The server sets
this variable whenever the default database changes. If there is
no default database, the variable has the same value as
`character_set_server'.

* `character_set_filesystem'

The file system character set. This variable is used to interpret
string literals that refer to file names, such as in the *Note
`LOAD DATA INFILE': load-data. and *Note `SELECT ... INTO
OUTFILE': select. statements and the `LOAD_FILE()' function. Such
file names are converted from `character_set_client' to
`character_set_filesystem' before the file opening attempt occurs.
The default value is `binary', which means that no conversion
occurs. For systems on which multi-byte file names are permitted,
a different value may be more appropriate. For example, if the
system represents file names using UTF-8, set
`character_set_filesystem' to `'utf8''. This variable was added in
MySQL 5.0.19.

* `character_set_results'

Options for character_set_results *Variable Name* `character_set_results'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

The character set used for returning query results such as result
sets or error messages to the client.

* `character_set_server'

The server's default character set.

* `character_set_system'

Options for character_set_system *Variable Name* `character_set_system'
*Variable Scope* Global
*Dynamic Variable* No
*Permitted
Values
*
*Type* `string'

The character set used by the server for storing identifiers. The
value is always `utf8'.

* `character_sets_dir'

The directory where character sets are installed.

* `collation_connection'

Options for collation_connection *Variable Name* `collation_connection'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Permitted
Values
*
*Type* `string'

The collation of the connection character set.

* `collation_database'

Options for collation_database *Variable Name* `collation_database'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes
*Footnote* This
option
is
dynamic,
but
only
the
server
should
set
this
information.
You
should
not
set
the
value
of
this
variable
manually.
*Permitted
Values
*
*Type* `string'

The collation used by the default database. The server sets this
variable whenever the default database changes. If there is no
default database, the variable has the same value as
`collation_server'.

* `collation_server'

The server's default collation.

* `completion_type'

Options for completion_type *Version Introduced* 5.0.3
*Command-Line `--completion_type=#'
Format*
*Option-File Format* `completion_type'
*Option Sets Yes,
Variable* `completion_type'
*Variable Name* `competion_type'
*Variable Scope* Global,
Session
*Dynamic Variable* Yes

The transaction completion type. This variable can take the values
shown in the following table.

Value Description
0 *Note `COMMIT': commit. and *Note `ROLLBACK':
commit. are unaffected. This is the default
value.
1 *Note `COMMIT': commit. and *Note `ROLLBACK':
commit. are equivalent to `COMMIT AND CHAIN' and
`ROLLBACK AND CHAIN', respectively. (A new
transaction starts immediately with the same
isolation level as the just-terminated
transaction.)
2 *Note `COMMIT': commit. and *Note `ROLLBACK':
commit. are equivalent to `COMMIT RELEASE' and
`ROLLBACK RELEASE', respectively. (The server
disconnects after terminating the transaction.)

`completion_type' affects transactions that begin with *Note
`START TRANSACTION': commit. or *Note `BEGIN': commit. and end
with *Note `COMMIT': commit. or *Note `ROLLBACK': commit. It does
not apply to implicit commits resulting from execution of the
statements listed in *Note implicit-commit::. It also does not
apply for *Note `XA COMMIT': xa-statements, *Note `XA ROLLBACK':
xa-statements, or when `autocommit=1'.

This variable was added in MySQL 5.0.3.

* `concurrent_insert'

Options for concurrent_insert *Command-Line `--concurrent_insert[=#]'
Format*
*Option-File Format* `concurrent_insert'
*Option Sets Yes,
Variable* `concurrent_insert'
*Variable Name* `concurrent_insert'
*Variable Scope* Global
*Dynamic Variable* Yes
*Permitted
Values
(<=
5.0.5)*
*Type* `boolean'
*Default* `TRUE'

If 1 (the default), MySQL permits *Note `INSERT': insert. and
*Note `SELECT': select. statements to run concurrently for
`MyISAM' tables that have no free blocks in the middle of the data
file. If you start *Note `mysqld': mysqld. with `--skip-new', this
variable is set to 0.

In MySQL 5.0.6, this variable was changed to take three integer
values:

Value Description
0 Disables concurrent inserts
1 (Default) Enables concurrent insert for `MyISAM'
tables that do not have holes
2 Enables concurrent inserts for all `MyISAM'
tables, even those that have holes. For a table
with a hole, new rows are inserted at the end of
the table if it is in use by another thread.
Otherwise, MySQL acquires a normal write lock and
inserts the row into the hole.

See also *Note gone-away::.

File: manual.info, Node: full-table, Next: cannot-create, Prev: communication-errors, Up: common-errors

C.5.2.13 `The table is full'
............................

The effective maximum table size for MySQL databases is usually
determined by operating system constraints on file sizes, not by MySQL
internal limits. The following table lists some examples of operating
system file-size limits. This is only a rough guide and is not intended
to be definitive. For the most up-to-date information, be sure to check
the documentation specific to your operating system.

Operating System File-size Limit
Win32 w/ FAT/FAT32 2GB/4GB
Win32 w/ NTFS 2TB (possibly larger)
Linux 2.2-Intel 32-bit 2GB (LFS: 4GB)
Linux 2.4+ (using ext3 file system) 4TB
Solaris 9/10 16TB
MacOS X w/ HFS+ 2TB
NetWare w/NSS file 8TB
system

Windows users, please note that FAT and VFAT (FAT32) are _not_
considered suitable for production use with MySQL. Use NTFS instead.

On Linux 2.2, you can get `MyISAM' tables larger than 2GB in size by
using the Large File Support (LFS) patch for the ext2 file system. Most
current Linux distributions are based on kernel 2.4 or higher and
include all the required LFS patches. On Linux 2.4, patches also exist
for ReiserFS to get support for big files (up to 2TB). With JFS and
XFS, petabyte and larger files are possible on Linux.

For a detailed overview about LFS in Linux, have a look at Andreas
Jaeger's `Large File Support in Linux' page at
`http://www.suse.de/~aj/linux_lfs.html'.

If you do encounter a full-table error, there are several reasons why
it might have occurred:

* The `InnoDB' storage engine maintains `InnoDB' tables within a
tablespace that can be created from several files. This enables a
table to exceed the maximum individual file size. The tablespace
can include raw disk partitions, which permits extremely large
tables. The maximum tablespace size is 64TB.

If you are using `InnoDB' tables and run out of room in the
`InnoDB' tablespace. In this case, the solution is to extend the
`InnoDB' tablespace. See *Note innodb-data-log-reconfiguration::.

* You are using `MyISAM' tables on an operating system that supports
files only up to 2GB in size and you have hit this limit for the
data file or index file.

* You are using a `MyISAM' table and the space required for the
table exceeds what is permitted by the internal pointer size.
`MyISAM' creates data and index table files to permit up to 4GB by
default (256TB as of MySQL 5.0.6), but this limit can be changed
up to the maximum permissible size of 65,536TB (256^7 - 1 bytes).

If you need a `MyISAM' table that is larger than the default limit
and your operating system supports large files, the *Note `CREATE
TABLE': create-table. statement supports `AVG_ROW_LENGTH' and
`MAX_ROWS' options. See *Note create-table::. The server uses these
options to determine how large a table to permit.

If the pointer size is too small for an existing table, you can
change the options with *Note `ALTER TABLE': alter-table. to
increase a table's maximum permissible size. See *Note
alter-table::.

ALTER TABLE TBL_NAME MAX_ROWS=1000000000 AVG_ROW_LENGTH=NNN;

You have to specify `AVG_ROW_LENGTH' only for tables with *Note
`BLOB': blob. or *Note `TEXT': blob. columns; in this case, MySQL
can't optimize the space required based only on the number of rows.

To change the default size limit for `MyISAM' tables, set the
`myisam_data_pointer_size', which sets the number of bytes used
for internal row pointers. The value is used to set the pointer
size for new tables if you do not specify the `MAX_ROWS' option.
The value of `myisam_data_pointer_size' can be from 2 to 7. A
value of 4 permits tables up to 4GB; a value of 6 permits tables
up to 256TB.

You can check the maximum data and index sizes by using this
statement:

SHOW TABLE STATUS FROM DB_NAME LIKE 'TBL_NAME';

You also can use *Note `myisamchk -dv /path/to/table-index-file':
myisamchk. See *Note show::, or *Note myisamchk::.

Other ways to work around file-size limits for `MyISAM' tables are
as follows:

* If your large table is read only, you can use *Note
`myisampack': myisampack. to compress it. *Note
`myisampack': myisampack. usually compresses a table by at
least 50%, so you can have, in effect, much bigger tables.
*Note `myisampack': myisampack. also can merge multiple
tables into a single table. See *Note myisampack::.

* MySQL includes a `MERGE' library that enables you to handle a
collection of `MyISAM' tables that have identical structure
as a single `MERGE' table. See *Note merge-storage-engine::.

* You are using the *Note `NDB': mysql-cluster. storage engine, in
which case you need to increase the values for the `DataMemory' and
`IndexMemory' configuration parameters in your `config.ini' file.
See *Note mysql-cluster-params-ndbd::.

* You are using the `MEMORY' (`HEAP') storage engine; in this case
you need to increase the value of the `max_heap_table_size' system
variable. See *Note server-system-variables::.

File: manual.info, Node: cannot-create, Next: commands-out-of-sync, Prev: full-table, Up: common-errors

C.5.2.14 `Can't create/write to file'
.....................................

If you get an error of the following type for some queries, it means
that MySQL cannot create a temporary file for the result set in the
temporary directory:

Can't create/write to file '\\sqla3fe_0.ism'.

The preceding error is a typical message for Windows; the Unix message
is similar.

One fix is to start *Note `mysqld': mysqld. with the `--tmpdir' option
or to add the option to the `[mysqld]' section of your option file. For
example, to specify a directory of `C:\temp', use these lines:

[mysqld]
tmpdir=C:/temp

The `C:\temp' directory must exist and have sufficient space for the
MySQL server to write to. See *Note option-files::.

Another cause of this error can be permissions issues. Make sure that
the MySQL server can write to the `tmpdir' directory.

Check also the error code that you get with *Note `perror': perror. One
reason the server cannot write to a table is that the file system is
full:

shell> perror 28
OS error code 28: No space left on device

If you get an error of the following type during startup, it indicates
that the file system or directory used for storing data files is write
protected. Providing the write error is to a test file, This error is
not serious and can be safely ignored.

Can't create test file /usr/local/mysql/data/master.lower-test

File: manual.info, Node: commands-out-of-sync, Next: ignoring-user, Prev: cannot-create, Up: common-errors

C.5.2.15 `Commands out of sync'
...............................

If you get `Commands out of sync; you can't run this command now' in
your client code, you are calling client functions in the wrong order.

This can happen, for example, if you are using *Note
`mysql_use_result()': mysql-use-result. and try to execute a new query
before you have called *Note `mysql_free_result()': mysql-free-result.
It can also happen if you try to execute two queries that return data
without calling *Note `mysql_use_result()': mysql-use-result. or *Note
`mysql_store_result()': mysql-store-result. in between.

File: manual.info, Node: ignoring-user, Next: cannot-find-table, Prev: commands-out-of-sync, Up: common-errors

C.5.2.16 `Ignoring user'
........................

If you get the following error, it means that when *Note `mysqld':
mysqld. was started or when it reloaded the grant tables, it found an
account in the `user' table that had an invalid password.

`Found wrong password for user 'SOME_USER'@'SOME_HOST'; ignoring user'

As a result, the account is simply ignored by the permission system.

The following list indicates possible causes of and fixes for this
problem:

* You may be running a new version of *Note `mysqld': mysqld. with
an old `user' table. You can check this by executing *Note
`mysqlshow mysql user': mysqlshow. to see whether the `Password'
column is shorter than 16 characters. If so, you can correct this
condition by running the `scripts/add_long_password' script.

* The account has an old password (eight characters long). Update
the account in the `user' table to have a new password.

* You have specified a password in the `user' table without using the
`PASSWORD()' function. Use *Note `mysql': mysql. to update the
account in the `user' table with a new password, making sure to
use the `PASSWORD()' function:

mysql> UPDATE user SET Password=PASSWORD('NEWPWD')
-> WHERE User='SOME_USER' AND Host='SOME_HOST';

File: manual.info, Node: cannot-find-table, Next: cannot-initialize-character-set, Prev: ignoring-user, Up: common-errors

C.5.2.17 `Table 'TBL_NAME' doesn't exist'
.........................................

If you get either of the following errors, it usually means that no
table exists in the default database with the given name:

Table 'TBL_NAME' doesn't exist
Can't find file: 'TBL_NAME' (errno: 2)

In some cases, it may be that the table does exist but that you are
referring to it incorrectly:

* Because MySQL uses directories and files to store databases and
tables, database and table names are case sensitive if they are
located on a file system that has case-sensitive file names.

* Even for file systems that are not case sensitive, such as on
Windows, all references to a given table within a query must use
the same lettercase.

You can check which tables are in the default database with *Note `SHOW
TABLES': show-tables. See *Note show::.

File: manual.info, Node: cannot-initialize-character-set, Next: not-enough-file-handles, Prev: cannot-find-table, Up: common-errors

C.5.2.18 `Can't initialize character set'
.........................................

You might see an error like this if you have character set problems:

MySQL Connection Failed: Can't initialize character set CHARSET_NAME

This error can have any of the following causes:

* The character set is a multi-byte character set and you have no
support for the character set in the client. In this case, you
need to recompile the client by running `configure' with the
`--with-charset=CHARSET_NAME' or
`--with-extra-charsets=CHARSET_NAME' option. See *Note
source-configuration-options::.

All standard MySQL binaries are compiled with
`--with-extra-charsets=complex' or (for Windows)
`--with-extra-charsets=complex', which enables support for all
multi-byte character sets. See *Note
source-configuration-options::.

* The character set is a simple character set that is not compiled
into *Note `mysqld': mysqld, and the character set definition
files are not in the place where the client expects to find them.

In this case, you need to use one of the following methods to
solve the problem:

* Recompile the client with support for the character set. See
*Note source-configuration-options::.

* Specify to the client the directory where the character set
definition files are located. For many clients, you can do
this with the `--character-sets-dir' option.

* Copy the character definition files to the path where the
client expects them to be.

File: manual.info, Node: not-enough-file-handles, Next: table-corruption, Prev: cannot-initialize-character-set, Up: common-errors

C.5.2.19 `'FILE' Not Found' and Similar Errors
..............................................

If you get `ERROR '...' not found (errno: 23)', `Can't open file: ...
(errno: 24)', or any other error with `errno 23' or `errno 24' from
MySQL, it means that you haven't allocated enough file descriptors for
the MySQL server. You can use the *Note `perror': perror. utility to
get a description of what the error number means:

shell> perror 23
OS error code 23: File table overflow
shell> perror 24
OS error code 24: Too many open files
shell> perror 11
OS error code 11: Resource temporarily unavailable

The problem here is that *Note `mysqld': mysqld. is trying to keep open
too many files simultaneously. You can either tell *Note `mysqld':
mysqld. not to open so many files at once or increase the number of
file descriptors available to *Note `mysqld': mysqld.

To tell *Note `mysqld': mysqld. to keep open fewer files at a time, you
can make the table cache smaller by reducing the value of the
`table_cache' system variable (the default value is 64). This may not
entirely prevent running out of file descriptors because in some
circumstances the server may attempt to extend the cache size
temporarily, as described in *Note table-cache::. Reducing the value of
`max_connections' also reduces the number of open files (the default
value is 100).

To change the number of file descriptors available to *Note `mysqld':
mysqld, you can use the `--open-files-limit' option to *Note
`mysqld_safe': mysqld-safe. or set the `open_files_limit' system
variable. See *Note server-system-variables::. The easiest way to set
these values is to add an option to your option file. See *Note
option-files::. If you have an old version of *Note `mysqld': mysqld.
that doesn't support setting the open files limit, you can edit the
*Note `mysqld_safe': mysqld-safe. script. There is a commented-out line
`ulimit -n 256' in the script. You can remove the ``#'' character to
uncomment this line, and change the number `256' to set the number of
file descriptors to be made available to *Note `mysqld': mysqld.

`--open-files-limit' and `ulimit' can increase the number of file
descriptors, but only up to the limit imposed by the operating system.
There is also a `hard' limit that can be overridden only if you start
*Note `mysqld_safe': mysqld-safe. or *Note `mysqld': mysqld. as `root'
(just remember that you also need to start the server with the `--user'
option in this case so that it does not continue to run as `root' after
it starts up). If you need to increase the operating system limit on
the number of file descriptors available to each process, consult the
documentation for your system.

*Note*:

If you run the `tcsh' shell, `ulimit' does not work! `tcsh' also
reports incorrect values when you ask for the current limits. In this
case, you should start *Note `mysqld_safe': mysqld-safe. using `sh'.

File: manual.info, Node: table-corruption, Prev: not-enough-file-handles, Up: common-errors

C.5.2.20 Table-Corruption Issues
................................

See also *Note server-options::, and *Note reproducible-test-case::.

File: manual.info, Node: installation-issues, Next: administration-issues, Prev: common-errors, Up: problems

C.5.3 Installation-Related Issues
---------------------------------

* Menu:

* file-permissions:: Problems with File Permissions

File: manual.info, Node: file-permissions, Prev: installation-issues, Up: installation-issues

C.5.3.1 Problems with File Permissions
......................................

If you have problems with file permissions, the `UMASK' environment
variable might be set incorrectly when *Note `mysqld': mysqld. starts.
For example, MySQL might issue the following error message when you
create a table:

ERROR: Can't find file: 'path/with/filename.frm' (Errcode: 13)

The default `UMASK' value is `0660'. You can change this behavior by
starting *Note `mysqld_safe': mysqld-safe. as follows:

shell> UMASK=384 # = 600 in octal
shell> export UMASK
shell> mysqld_safe &

By default, MySQL creates database and `RAID' directories with an
access permission value of `0700'. You can modify this behavior by
setting the `UMASK_DIR' variable. If you set its value, new directories
are created with the combined `UMASK' and `UMASK_DIR' values. For
example, if you want to give group access to all new directories, you
can do this:

shell> UMASK_DIR=504 # = 770 in octal
shell> export UMASK_DIR
shell> mysqld_safe &

MySQL assumes that the value for `UMASK' or `UMASK_DIR' is in octal if
it starts with a zero.

See *Note environment-variables::.

File: manual.info, Node: administration-issues, Next: query-issues, Prev: installation-issues, Up: problems

C.5.4 Administration-Related Issues
-----------------------------------

* Menu:

* resetting-permissions:: How to Reset the Root Password
* crashing:: What to Do If MySQL Keeps Crashing
* full-disk:: How MySQL Handles a Full Disk
* temporary-files:: Where MySQL Stores Temporary Files
* problems-with-mysql-sock:: How to Protect or Change the MySQL Unix Socket File
* timezone-problems:: Time Zone Problems

File: manual.info, Node: resetting-permissions, Next: crashing, Prev: administration-issues, Up: administration-issues

C.5.4.1 How to Reset the Root Password
......................................

* Menu:

* resetting-permissions-windows:: Resetting the Root Password: Windows Systems
* resetting-permissions-unix:: Resetting the Root Password: Unix Systems
* resetting-permissions-generic:: Resetting the Root Password: Generic Instructions

If you have never set a `root' password for MySQL, the server does not
require a password at all for connecting as `root'. However, this is
insecure. For instructions on assigning passwords, see *Note
default-privileges::.

If you know the `root' password, but want to change it, see *Note
set-password::.

If you set a `root' password previously, but have forgotten it, you can
set a new password. The following sections provide instructions for
Windows and Unix systems, as well as generic instructions that apply to
any system.

File: manual.info, Node: resetting-permissions-windows, Next: resetting-permissions-unix, Prev: resetting-permissions, Up: resetting-permissions

C.5.4.2 Resetting the Root Password: Windows Systems
....................................................

On Windows, use the following procedure to reset the password for all
MySQL `root' accounts:

1. Log on to your system as Administrator.

2. Stop the MySQL server if it is running. For a server that is
running as a Windows service, go to the Services manager: From the
`Start' menu, select `Control Panel', then `Administrative Tools',
then `Services'. Find the MySQL service in the list and stop it.

If your server is not running as a service, you may need to use
the Task Manager to force it to stop.

3. Create a text file containing the following statements. Replace
the password with the password that you want to use.

UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
FLUSH PRIVILEGES;

Write the *Note `UPDATE': update. and *Note `FLUSH': flush.
statements each on a single line. The *Note `UPDATE': update.
statement resets the password for all `root' accounts, and the
*Note `FLUSH': flush. statement tells the server to reload the
grant tables into memory so that it notices the password change.

4. Save the file. For this example, the file will be named
`C:\mysql-init.txt'.

5. Open a console window to get to the command prompt: From the
`Start' menu, select `Run', then enter `cmd' as the command to be
run.

6. Start the MySQL server with the special `--init-file' option
(notice that the backslash in the option value is doubled):

C:\> C:\mysql\bin\mysqld-nt --init-file=C:\\mysql-init.txt

If you installed MySQL to a location other than `C:\mysql', adjust
the command accordingly.

The server executes the contents of the file named by the
`--init-file' option at startup, changing each `root' account
password.

You can also add the `--console' option to the command if you want
server output to appear in the console window rather than in a log
file.

If you installed MySQL using the MySQL Installation Wizard, you
may need to specify a `--defaults-file' option:

C:\> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld-nt.exe"
--defaults-file="C:\\Program Files\\MySQL\\MySQL Server 5.0\\my.ini"
--init-file=C:\\mysql-init.txt

The appropriate `--defaults-file' setting can be found using the
Services Manager: From the `Start' menu, select `Control Panel',
then `Administrative Tools', then `Services'. Find the MySQL
service in the list, right-click it, and choose the `Properties'
option. The `Path to executable' field contains the
`--defaults-file' setting.

7. After the server has started successfully, delete
`C:\mysql-init.txt'.

You should now be able to connect to the MySQL server as `root' using
the new password. Stop the MySQL server, then restart it in normal mode
again. If you run the server as a service, start it from the Windows
Services window. If you start the server manually, use whatever command
you normally use.

File: manual.info, Node: resetting-permissions-unix, Next: resetting-permissions-generic, Prev: resetting-permissions-windows, Up: resetting-permissions

C.5.4.3 Resetting the Root Password: Unix Systems
.................................................

On Unix, use the following procedure to reset the password for all
MySQL `root' accounts. The instructions assume that you will start the
server so that it runs using the Unix login account that you normally
use for running the server. For example, if you run the server using
the `mysql' login account, you should log in as `mysql' before using the
instructions. Alternatively, you can log in as `root', but in this case
you _must_ start *Note `mysqld': mysqld. with the `--user=mysql'
option. If you start the server as `root' without using
`--user=mysql', the server may create `root'-owned files in the data
directory, such as log files, and these may cause permission-related
problems for future server startups. If that happens, you will need to
either change the ownership of the files to `mysql' or remove them.

1. Log on to your system as the Unix user that the *Note `mysqld':
mysqld. server runs as (for example, `mysql').

2. Locate the `.pid' file that contains the server's process ID. The
exact location and name of this file depend on your distribution,
host name, and configuration. Common locations are
`/var/lib/mysql/', `/var/run/mysqld/', and
`/usr/local/mysql/data/'. Generally, the file name has an
extension of `.pid' and begins with either `mysqld' or your
system's host name.

You can stop the MySQL server by sending a normal `kill' (not
`kill -9') to the *Note `mysqld': mysqld. process, using the path
name of the `.pid' file in the following command:

shell> kill `cat /mysql-data-directory/host_name.pid`

Use backticks (not forward quotation marks) with the `cat'
command. These cause the output of `cat' to be substituted into the
`kill' command.

3. Create a text file containing the following statements. Replace
the password with the password that you want to use.

UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
FLUSH PRIVILEGES;

4. Save the file. For this example, the file will be named
`/home/me/mysql-init'. The file contains the password, so it
should not be saved where it can be read by other users.

5. Start the MySQL server with the special `--init-file' option:

shell> mysqld_safe --init-file=/home/me/mysql-init &

The server executes the contents of the file named by the
`--init-file' option at startup, changing each `root' account
password.

6. After the server has started successfully, delete
`/home/me/mysql-init'.

You should now be able to connect to the MySQL server as `root' using
the new password. Stop the server and restart it normally.

File: manual.info, Node: resetting-permissions-generic, Prev: resetting-permissions-unix, Up: resetting-permissions

C.5.4.4 Resetting the Root Password: Generic Instructions
.........................................................

The preceding sections provide password-resetting instructions for
Windows and Unix systems. Alternatively, on any platform, you can set
the new password using the *Note `mysql': mysql. client (but this
approach is less secure):

1. Stop *Note `mysqld': mysqld. and restart it with the
`--skip-grant-tables' option. This enables anyone to connect
without a password and with all privileges.

2. Connect to the *Note `mysqld': mysqld. server with this command:

shell> mysql

3. Issue the following statements in the *Note `mysql': mysql.
client. Replace the password with the password that you want to
use.

mysql> UPDATE mysql.user SET Password=PASSWORD('MyNewPass')
-> WHERE User='root';
mysql> FLUSH PRIVILEGES;

The *Note `FLUSH': flush. statement tells the server to reload the
grant tables into memory so that it notices the password change.

You should now be able to connect to the MySQL server as `root' using
the new password. Stop the server and restart it normally (without the
`--skip-grant-tables' option).

File: manual.info, Node: crashing, Next: full-disk, Prev: resetting-permissions, Up: administration-issues

C.5.4.5 What to Do If MySQL Keeps Crashing
..........................................

Each MySQL version is tested on many platforms before it is released.
This doesn't mean that there are no bugs in MySQL, but if there are
bugs, they should be very few and can be hard to find. If you have a
problem, it always helps if you try to find out exactly what crashes
your system, because you have a much better chance of getting the
problem fixed quickly.

First, you should try to find out whether the problem is that the *Note
`mysqld': mysqld. server dies or whether your problem has to do with
your client. You can check how long your *Note `mysqld': mysqld. server
has been up by executing *Note `mysqladmin version': mysqladmin. If
*Note `mysqld': mysqld. has died and restarted, you may find the reason
by looking in the server's error log. See *Note error-log::.

On some systems, you can find in the error log a stack trace of where
*Note `mysqld': mysqld. died that you can resolve with the
`resolve_stack_dump' program. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting). Note that the
variable values written in the error log may not always be 100% correct.

Many server crashes are caused by corrupted data files or index files.
MySQL updates the files on disk with the `write()' system call after
every SQL statement and before the client is notified about the result.
(This is not true if you are running with `--delay-key-write', in which
case data files are written but not index files.) This means that data
file contents are safe even if *Note `mysqld': mysqld. crashes, because
the operating system ensures that the unflushed data is written to
disk. You can force MySQL to flush everything to disk after every SQL
statement by starting *Note `mysqld': mysqld. with the `--flush' option.

The preceding means that normally you should not get corrupted tables
unless one of the following happens:

* The MySQL server or the server host was killed in the middle of an
update.

* You have found a bug in *Note `mysqld': mysqld. that caused it to
die in the middle of an update.

* Some external program is manipulating data files or index files at
the same time as *Note `mysqld': mysqld. without locking the
table properly.

* You are running many *Note `mysqld': mysqld. servers using the
same data directory on a system that doesn't support good file
system locks (normally handled by the `lockd' lock manager), or
you are running multiple servers with external locking disabled.

* You have a crashed data file or index file that contains very
corrupt data that confused *Note `mysqld': mysqld.

* You have found a bug in the data storage code. This isn't likely,
but it is at least possible. In this case, you can try to change
the storage engine to another engine by using *Note `ALTER TABLE':
alter-table. on a repaired copy of the table.

Because it is very difficult to know why something is crashing, first
try to check whether things that work for others crash for you. Please
try the following things:

* Stop the *Note `mysqld': mysqld. server with *Note `mysqladmin
shutdown': mysqladmin, run *Note `myisamchk --silent --force
*/*.MYI': myisamchk. from the data directory to check all `MyISAM'
tables, and restart *Note `mysqld': mysqld. This ensures that you
are running from a clean state. See *Note server-administration::.

* Start *Note `mysqld': mysqld. with the general query log enabled
(see *Note query-log::). Then try to determine from the
information written to the log whether some specific query kills
the server. About 95% of all bugs are related to a particular
query. Normally, this is one of the last queries in the log file
just before the server restarts. See *Note query-log::. If you can
repeatedly kill MySQL with a specific query, even when you have
checked all tables just before issuing it, then you have been able
to locate the bug and should submit a bug report for it. See *Note
bug-reports::.

* Try to make a test case that we can use to repeat the problem. See
MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* Try running the tests in the `mysql-test' directory and the MySQL
benchmarks. See *Note mysql-test-suite::. They should test MySQL
rather well. You can also add code to the benchmarks that
simulates your application. The benchmarks can be found in the
`sql-bench' directory in a source distribution or, for a binary
distribution, in the `sql-bench' directory under your MySQL
installation directory.

* Try the `fork_big.pl' script. (It is located in the `tests'
directory of source distributions.)

* If you configure MySQL for debugging, it is much easier to gather
information about possible errors if something goes wrong.
Configuring MySQL for debugging causes a safe memory allocator to
be included that can find some errors. It also provides a lot of
output about what is happening. Reconfigure MySQL with the
`--with-debug' or `--with-debug=full' option to `configure' and
then recompile. See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

* Make sure that you have applied the latest patches for your
operating system.

* Use the `--skip-external-locking' option to *Note `mysqld':
mysqld. On some systems, the `lockd' lock manager does not work
properly; the `--skip-external-locking' option tells *Note
`mysqld': mysqld. not to use external locking. (This means that
you cannot run two *Note `mysqld': mysqld. servers on the same data
directory and that you must be careful if you use *Note
`myisamchk': myisamchk. Nevertheless, it may be instructive to try
the option as a test.)

* Have you tried *Note `mysqladmin -u root processlist': mysqladmin.
when *Note `mysqld': mysqld. appears to be running but not
responding? Sometimes *Note `mysqld': mysqld. is not comatose even
though you might think so. The problem may be that all connections
are in use, or there may be some internal lock problem. *Note
`mysqladmin -u root processlist': mysqladmin. usually is able to
make a connection even in these cases, and can provide useful
information about the current number of connections and their
status.

* Run the command *Note `mysqladmin -i 5 status': mysqladmin. or
*Note `mysqladmin -i 5 -r status': mysqladmin. in a separate
window to produce statistics while you run your other queries.

* Try the following:

1. Start *Note `mysqld': mysqld. from `gdb' (or another
debugger). See MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

2. Run your test scripts.

3. Print the backtrace and the local variables at the three
lowest levels. In `gdb', you can do this with the following
commands when *Note `mysqld': mysqld. has crashed inside
`gdb':

backtrace
info local
up
info local
up
info local

With `gdb', you can also examine which threads exist with
`info threads' and switch to a specific thread with `thread
N', where N is the thread ID.

* Try to simulate your application with a Perl script to force MySQL
to crash or misbehave.

* Send a normal bug report. See *Note bug-reports::. Be even more
detailed than usual. Because MySQL works for many people, it may
be that the crash results from something that exists only on your
computer (for example, an error that is related to your particular
system libraries).

* If you have a problem with tables containing dynamic-length rows
and you are using only *Note `VARCHAR': char. columns (not *Note
`BLOB': blob. or *Note `TEXT': blob. columns), you can try to
change all *Note `VARCHAR': char. to *Note `CHAR': char. with
*Note `ALTER TABLE': alter-table. This forces MySQL to use
fixed-size rows. Fixed-size rows take a little extra space, but
are much more tolerant to corruption.

The current dynamic row code has been in use for several years
with very few problems, but dynamic-length rows are by nature more
prone to errors, so it may be a good idea to try this strategy to
see whether it helps.

* Do not rule out your server hardware when diagnosing problems.
Defective hardware can be the cause of data corruption. Particular
attention should be paid to your memory and disk subsystems when
troubleshooting hardware.

File: manual.info, Node: full-disk, Next: temporary-files, Prev: crashing, Up: administration-issues

C.5.4.6 How MySQL Handles a Full Disk
.....................................

This section describes how MySQL responds to disk-full errors (such as
`no space left on device'), and to quota-exceeded errors (such as
`write failed' or `user block limit reached').

This section is relevant for writes to `MyISAM' tables. It also applies
for writes to binary log files and binary log index file, except that
references to `row' and `record' should be understood to mean `event.'

When a disk-full condition occurs, MySQL does the following:

* It checks once every minute to see whether there is enough space
to write the current row. If there is enough space, it continues
as if nothing had happened.

* Every 10 minutes it writes an entry to the log file, warning about
the disk-full condition.

To alleviate the problem, you can take the following actions:

* To continue, you only have to free enough disk space to insert all
records.

* To abort the thread, you must use *Note `mysqladmin kill':
mysqladmin. The thread is aborted the next time it checks the disk
(in one minute).

* Other threads might be waiting for the table that caused the
disk-full condition. If you have several `locked' threads, killing
the one thread that is waiting on the disk-full condition enables
the other threads to continue.

Exceptions to the preceding behavior are when you use *Note `REPAIR
TABLE': repair-table. or *Note `OPTIMIZE TABLE': optimize-table. or
when the indexes are created in a batch after *Note `LOAD DATA INFILE':
load-data. or after an *Note `ALTER TABLE': alter-table. statement. All
of these statements may create large temporary files that, if left to
themselves, would cause big problems for the rest of the system. If the
disk becomes full while MySQL is doing any of these operations, it
removes the big temporary files and mark the table as crashed. The
exception is that for *Note `ALTER TABLE': alter-table, the old table
is left unchanged.

File: manual.info, Node: temporary-files, Next: problems-with-mysql-sock, Prev: full-disk, Up: administration-issues

C.5.4.7 Where MySQL Stores Temporary Files
..........................................

On Unix, MySQL uses the value of the `TMPDIR' environment variable as
the path name of the directory in which to store temporary files. If
`TMPDIR' is not set, MySQL uses the system default, which is usually
`/tmp', `/var/tmp', or `/usr/tmp'.

On Windows, Netware and OS2, MySQL checks in order the values of the
`TMPDIR', `TEMP', and `TMP' environment variables. For the first one
found to be set, MySQL uses it and does not check those remaining. If
none of `TMPDIR', `TEMP', or `TMP' are set, MySQL uses the Windows
system default, which is usually `C:\windows\temp\'.

If the file system containing your temporary file directory is too
small, you can use the `--tmpdir' option to *Note `mysqld': mysqld. to
specify a directory in a file system where you have enough space.

In MySQL 5.0, the `--tmpdir' option can be set to a list of several
paths that are used in round-robin fashion. Paths should be separated
by colon characters (``:'') on Unix and semicolon characters (``;'') on
Windows, NetWare, and OS/2.

*Note*:

To spread the load effectively, these paths should be located on
different _physical_ disks, not different partitions of the same disk.

If the MySQL server is acting as a replication slave, you should not
set `--tmpdir' to point to a directory on a memory-based file system or
to a directory that is cleared when the server host restarts. A
replication slave needs some of its temporary files to survive a
machine restart so that it can replicate temporary tables or *Note
`LOAD DATA INFILE': load-data. operations. If files in the temporary
file directory are lost when the server restarts, replication fails.

MySQL creates all temporary files as hidden files. This ensures that
the temporary files are removed if *Note `mysqld': mysqld. is
terminated. The disadvantage of using hidden files is that you do not
see a big temporary file that fills up the file system in which the
temporary file directory is located.

When sorting (`ORDER BY' or `GROUP BY'), MySQL normally uses one or two
temporary files. The maximum disk space required is determined by the
following expression:

(length of what is sorted + sizeof(row pointer))
* number of matched rows
* 2

The row pointer size is usually four bytes, but may grow in the future
for really big tables.

For some *Note `SELECT': select. queries, MySQL also creates temporary
SQL tables. These are not hidden and have names of the form `SQL_*'.

*Note `ALTER TABLE': alter-table. creates a temporary table in the same
directory as the original table.

File: manual.info, Node: problems-with-mysql-sock, Next: timezone-problems, Prev: temporary-files, Up: administration-issues

C.5.4.8 How to Protect or Change the MySQL Unix Socket File
...........................................................

The default location for the Unix socket file that the server uses for
communication with local clients is `/tmp/mysql.sock'. (For some
distribution formats, the directory might be different, such as
`/var/lib/mysql' for RPMs.)

On some versions of Unix, anyone can delete files in the `/tmp'
directory or other similar directories used for temporary files. If the
socket file is located in such a directory on your system, this might
cause problems.

On most versions of Unix, you can protect your `/tmp' directory so that
files can be deleted only by their owners or the superuser (`root'). To
do this, set the `sticky' bit on the `/tmp' directory by logging in as
`root' and using the following command:

shell> chmod +t /tmp

You can check whether the `sticky' bit is set by executing `ls -ld
/tmp'. If the last permission character is `t', the bit is set.

Another approach is to change the place where the server creates the
Unix socket file. If you do this, you should also let client programs
know the new location of the file. You can specify the file location in
several ways:

* Specify the path in a global or local option file. For example,
put the following lines in `/etc/my.cnf':

[mysqld]
socket=/path/to/socket

[client]
socket=/path/to/socket

See *Note option-files::.

* Specify a `--socket' option on the command line to *Note
`mysqld_safe': mysqld-safe. and when you run client programs.

* Set the `MYSQL_UNIX_PORT' environment variable to the path of the
Unix socket file.

* Recompile MySQL from source to use a different default Unix socket
file location. Define the path to the file with the
`--with-unix-socket-path' option when you run `configure'. See
*Note source-configuration-options::.

You can test whether the new socket location works by attempting to
connect to the server with this command:

shell> mysqladmin --socket=/path/to/socket version

File: manual.info, Node: timezone-problems, Prev: problems-with-mysql-sock, Up: administration-issues

C.5.4.9 Time Zone Problems
..........................

If you have a problem with `SELECT NOW()' returning values in UTC and
not your local time, you have to tell the server your current time
zone. The same applies if `UNIX_TIMESTAMP()' returns the wrong value.
This should be done for the environment in which the server runs; for
example, in *Note `mysqld_safe': mysqld-safe. or *Note `mysql.server':
mysql-server. See *Note environment-variables::.

You can set the time zone for the server with the
`--timezone=TIMEZONE_NAME' option to *Note `mysqld_safe': mysqld-safe.
You can also set it by setting the `TZ' environment variable before you
start *Note `mysqld': mysqld.

The permissible values for `--timezone' or `TZ' are system dependent.
Consult your operating system documentation to see what values are
acceptable.

File: manual.info, Node: query-issues, Next: optimizer-issues, Prev: administration-issues, Up: problems

C.5.5 Query-Related Issues
--------------------------

* Menu:

* case-sensitivity:: Case Sensitivity in String Searches
* using-date:: Problems Using `DATE' Columns
* problems-with-null:: Problems with `NULL' Values
* problems-with-alias:: Problems with Column Aliases
* non-transactional-tables:: Rollback Failure for Nontransactional Tables
* deleting-from-related-tables:: Deleting Rows from Related Tables
* no-matching-rows:: Solving Problems with No Matching Rows
* problems-with-float:: Problems with Floating-Point Values

File: manual.info, Node: case-sensitivity, Next: using-date, Prev: query-issues, Up: query-issues

C.5.5.1 Case Sensitivity in String Searches
...........................................

For nonbinary strings (*Note `CHAR': char, *Note `VARCHAR': char, *Note
`TEXT': blob.), string searches use the collation of the comparison
operands. For binary strings (*Note `BINARY': binary-varbinary, *Note
`VARBINARY': binary-varbinary, *Note `BLOB': blob.), comparisons use the
numeric values of the bytes in the operands; this means that for
alphabetic characters, comparisons will be case sensitive.

A comparison between a nonbinary string and binary string is treated as
a comparison of binary strings.

Simple comparison operations (`>=, >, =, <, <=', sorting, and grouping)
are based on each character's `sort value.' Characters with the same
sort value are treated as the same character. For example, if ``e'' and
``e''' have the same sort value in a given collation, they compare as
equal.

The default character set and collation are `latin1' and
`latin1_swedish_ci', so nonbinary string comparisons are case
insensitive by default. This means that if you search with `COL_NAME
LIKE 'a%'', you get all column values that start with `A' or `a'. To
make this search case sensitive, make sure that one of the operands has
a case sensitive or binary collation. For example, if you are comparing
a column and a string that both have the `latin1' character set, you
can use the `COLLATE' operator to cause either operand to have the
`latin1_general_cs' or `latin1_bin' collation:

COL_NAME COLLATE latin1_general_cs LIKE 'a%'
COL_NAME LIKE 'a%' COLLATE latin1_general_cs
COL_NAME COLLATE latin1_bin LIKE 'a%'
COL_NAME LIKE 'a%' COLLATE latin1_bin

If you want a column always to be treated in case-sensitive fashion,
declare it with a case sensitive or binary collation. See *Note
create-table::.

To cause a case-sensitive comparison of nonbinary strings to be case
insensitive, use `COLLATE' to name a case-insensitive collation. The
strings in the following example normally are case sensitive, but
`COLLATE' changes the comparison to be case insensitive:

mysql> SET @s1 = 'MySQL' COLLATE latin1_bin,
-> @s2 = 'mysql' COLLATE latin1_bin;
mysql> SELECT @s1 = @s2;
+-----------+
| @s1 = @s2 |
+-----------+
| 0 |
+-----------+
mysql> SELECT @s1 COLLATE latin1_swedish_ci = @s2;
+-------------------------------------+
| @s1 COLLATE latin1_swedish_ci = @s2 |
+-------------------------------------+
| 1 |
+-------------------------------------+

A binary string is case sensitive in comparisons. To compare the string
as case insensitive, convert it to a nonbinary string and use `COLLATE'
to name a case-insensitive collation:

mysql> SET @s = BINARY 'MySQL';
mysql> SELECT @s = 'mysql';
+--------------+
| @s = 'mysql' |
+--------------+
| 0 |
+--------------+
mysql> SELECT CONVERT(@s USING latin1) COLLATE latin1_swedish_ci = 'mysql';
+--------------------------------------------------------------+
| CONVERT(@s USING latin1) COLLATE latin1_swedish_ci = 'mysql' |
+--------------------------------------------------------------+
| 1 |
+--------------------------------------------------------------+

To determine whether a value will compare as a nonbinary or binary
string, use the `COLLATION()' function. This example shows that
`VERSION()' returns a string that has a case-insensitive collation, so
comparisons are case insensitive:

mysql> SELECT COLLATION(VERSION());
+----------------------+
| COLLATION(VERSION()) |
+----------------------+
| utf8_general_ci |
+----------------------+

For binary strings, the collation value is `binary', so comparisons
will be case sensitive. One context in which you will see `binary' is
for compression and encryption functions, which return binary strings
as a general rule: string:

File: manual.info, Node: using-date, Next: problems-with-null, Prev: case-sensitivity, Up: query-issues

C.5.5.2 Problems Using `DATE' Columns
.....................................

The format of a *Note `DATE': datetime. value is `'YYYY-MM-DD''.
According to standard SQL, no other format is permitted. You should use
this format in *Note `UPDATE': update. expressions and in the `WHERE'
clause of *Note `SELECT': select. statements. For example:

mysql> SELECT * FROM TBL_NAME WHERE date >= '2003-05-05';

As a convenience, MySQL automatically converts a date to a number if
the date is used in a numeric context (and vice versa). It is also
smart enough to permit a `relaxed' string form when updating and in a
`WHERE' clause that compares a date to a *Note `TIMESTAMP': datetime,
*Note `DATE': datetime, or *Note `DATETIME': datetime. column.
(`Relaxed form' means that any punctuation character may be used as the
separator between parts. For example, `'2004-08-15'' and `'2004#08#15''
are equivalent.) MySQL can also convert a string containing no
separators (such as `'20040815''), provided it makes sense as a date.

When you compare a *Note `DATE': datetime, *Note `TIME': time, *Note
`DATETIME': datetime, or *Note `TIMESTAMP': datetime. to a constant
string with the `<', `<=', `=', `>=', `>', or `BETWEEN' operators,
MySQL normally converts the string to an internal long integer for
faster comparison (and also for a bit more `relaxed' string checking).
However, this conversion is subject to the following exceptions:

* When you compare two columns

* When you compare a *Note `DATE': datetime, *Note `TIME': time,
*Note `DATETIME': datetime, or *Note `TIMESTAMP': datetime. column
to an expression

* When you use any other comparison method than those just listed,
such as `IN' or `STRCMP()'.

For these exceptional cases, the comparison is done by converting the
objects to strings and performing a string comparison.

To keep things safe, assume that strings are compared as strings and
use the appropriate string functions if you want to compare a temporal
value to a string.

The special date `'0000-00-00'' can be stored and retrieved as
`'0000-00-00'.' When using a `'0000-00-00'' date through MyODBC, it is
automatically converted to `NULL' in MyODBC 2.50.12 and above, because
ODBC can't handle this kind of date.

Because MySQL performs the conversions described above, the following
statements work:

mysql> INSERT INTO TBL_NAME (idate) VALUES (19970505);
mysql> INSERT INTO TBL_NAME (idate) VALUES ('19970505');
mysql> INSERT INTO TBL_NAME (idate) VALUES ('97-05-05');
mysql> INSERT INTO TBL_NAME (idate) VALUES ('1997.05.05');
mysql> INSERT INTO TBL_NAME (idate) VALUES ('1997 05 05');
mysql> INSERT INTO TBL_NAME (idate) VALUES ('0000-00-00');

mysql> SELECT idate FROM TBL_NAME WHERE idate >= '1997-05-05';
mysql> SELECT idate FROM TBL_NAME WHERE idate >= 19970505;
mysql> SELECT MOD(idate,100) FROM TBL_NAME WHERE idate >= 19970505;
mysql> SELECT idate FROM TBL_NAME WHERE idate >= '19970505';

However, the following does not work:

mysql> SELECT idate FROM TBL_NAME WHERE STRCMP(idate,'20030505')=0;

`STRCMP()' is a string function, so it converts `idate' to a string in
`'YYYY-MM-DD'' format and performs a string comparison. It does not
convert `'20030505'' to the date `'2003-05-05'' and perform a date
comparison.

If you are using the `ALLOW_INVALID_DATES' SQL mode, MySQL permits you
to store dates that are given only limited checking: MySQL requires
only that the day is in the range from 1 to 31 and the month is in the
range from 1 to 12.

This makes MySQL very convenient for Web applications where you obtain
year, month, and day in three different fields and you want to store
exactly what the user inserted (without date validation).

If you are not using the `NO_ZERO_IN_DATE' SQL mode, the day or month
part can be zero. This is convenient if you want to store a birthdate
in a *Note `DATE': datetime. column and you know only part of the date.

If you are not using the `NO_ZERO_DATE' SQL mode, MySQL also permits
you to store `'0000-00-00'' as a `dummy date.' This is in some cases
more convenient than using `NULL' values.

If the date cannot be converted to any reasonable value, a `0' is
stored in the *Note `DATE': datetime. column, which is retrieved as
`'0000-00-00''. This is both a speed and a convenience issue. We
believe that the database server's responsibility is to retrieve the
same date you stored (even if the data was not logically correct in all
cases). We think it is up to the application and not the server to
check the dates.

If you want MySQL to check all dates and accept only legal dates
(unless overridden by IGNORE), you should set `sql_mode' to
`"NO_ZERO_IN_DATE,NO_ZERO_DATE"'.

Date handling in MySQL 5.0.1 and earlier works like MySQL 5.0.2 with the
`ALLOW_INVALID_DATES' SQL mode enabled.

File: manual.info, Node: problems-with-null, Next: problems-with-alias, Prev: using-date, Up: query-issues

C.5.5.3 Problems with `NULL' Values
...................................

The concept of the `NULL' value is a common source of confusion for
newcomers to SQL, who often think that `NULL' is the same thing as an
empty string `'''. This is not the case. For example, the following
statements are completely different:

mysql> INSERT INTO my_table (phone) VALUES (NULL);
mysql> INSERT INTO my_table (phone) VALUES ('');

Both statements insert a value into the `phone' column, but the first
inserts a `NULL' value and the second inserts an empty string. The
meaning of the first can be regarded as `phone number is not known' and
the meaning of the second can be regarded as `the person is known to
have no phone, and thus no phone number.'

To help with `NULL' handling, you can use the `IS NULL' and `IS NOT
NULL' operators and the `IFNULL()' function.

In SQL, the `NULL' value is never true in comparison to any other
value, even `NULL'. An expression that contains `NULL' always produces
a `NULL' value unless otherwise indicated in the documentation for the
operators and functions involved in the expression. All columns in the
following example return `NULL':

mysql> SELECT NULL, 1+NULL, CONCAT('Invisible',NULL);

If you want to search for column values that are `NULL', you cannot use
an `expr = NULL' test. The following statement returns no rows, because
`expr = NULL' is never true for any expression:

mysql> SELECT * FROM my_table WHERE phone = NULL;

To look for `NULL' values, you must use the `IS NULL' test. The
following statements show how to find the `NULL' phone number and the
empty phone number:

mysql> SELECT * FROM my_table WHERE phone IS NULL;
mysql> SELECT * FROM my_table WHERE phone = '';

See *Note working-with-null::, for additional information and examples.

You can add an index on a column that can have `NULL' values if you are
using the `MyISAM', `InnoDB', or `BDB', or `MEMORY' storage engine.
Otherwise, you must declare an indexed column `NOT NULL', and you
cannot insert `NULL' into the column.

When reading data with *Note `LOAD DATA INFILE': load-data, empty or
missing columns are updated with `'''. If you want a `NULL' value in a
column, you should use `\N' in the data file. The literal word ``NULL''
may also be used under some circumstances. See *Note load-data::.

When using `DISTINCT', `GROUP BY', or `ORDER BY', all `NULL' values are
regarded as equal.

When using `ORDER BY', `NULL' values are presented first, or last if
you specify `DESC' to sort in descending order.

Aggregate (summary) functions such as `COUNT()', `MIN()', and `SUM()'
ignore `NULL' values. The exception to this is `COUNT(*)', which counts
rows and not individual column values. For example, the following
statement produces two counts. The first is a count of the number of
rows in the table, and the second is a count of the number of
non-`NULL' values in the `age' column:

mysql> SELECT COUNT(*), COUNT(age) FROM person;

For some data types, MySQL handles `NULL' values specially. If you
insert `NULL' into a *Note `TIMESTAMP': datetime. column, the current
date and time is inserted. If you insert `NULL' into an integer or
floating-point column that has the `AUTO_INCREMENT' attribute, the next
number in the sequence is inserted.

File: manual.info, Node: problems-with-alias, Next: non-transactional-tables, Prev: problems-with-null, Up: query-issues

C.5.5.4 Problems with Column Aliases
....................................

An alias can be used in a query select list to give a column a
different name. You can use the alias in `GROUP BY', `ORDER BY', or
`HAVING' clauses to refer to the column:

SELECT SQRT(a*b) AS root FROM TBL_NAME
GROUP BY root HAVING root > 0;
SELECT id, COUNT(*) AS cnt FROM TBL_NAME
GROUP BY id HAVING cnt > 0;
SELECT id AS 'Customer identity' FROM TBL_NAME;

Standard SQL disallows references to column aliases in a `WHERE'
clause. This restriction is imposed because when the `WHERE' clause is
evaluated, the column value may not yet have been determined. For
example, the following query is illegal:

SELECT id, COUNT(*) AS cnt FROM TBL_NAME
WHERE cnt > 0 GROUP BY id;

The `WHERE' clause determines which rows should be included in the
`GROUP BY' clause, but it refers to the alias of a column value that is
not known until after the rows have been selected, and grouped by the
`GROUP BY'.

In the select list of a query, a quoted column alias can be specified
using identifier or string quoting characters:

SELECT 1 AS `one`, 2 AS 'two';

Elsewhere in the statement, quoted references to the alias must use
identifier quoting or the reference is treated as a string literal. For
example, this statement groups by the values in column `id', referenced
using the alias ``a`':

SELECT id AS 'a', COUNT(*) AS cnt FROM TBL_NAME
GROUP BY `a`;

But this statement groups by the literal string `'a'' and will not work
as expected:

SELECT id AS 'a', COUNT(*) AS cnt FROM TBL_NAME
GROUP BY 'a';

File: manual.info, Node: non-transactional-tables, Next: deleting-from-related-tables, Prev: problems-with-alias, Up: query-issues

C.5.5.5 Rollback Failure for Nontransactional Tables
....................................................

If you receive the following message when trying to perform a *Note
`ROLLBACK': commit, it means that one or more of the tables you used in
the transaction do not support transactions:

Warning: Some non-transactional changed tables couldn't be rolled back

These nontransactional tables are not affected by the *Note `ROLLBACK':
commit. statement.

If you were not deliberately mixing transactional and nontransactional
tables within the transaction, the most likely cause for this message
is that a table you thought was transactional actually is not. This can
happen if you try to create a table using a transactional storage
engine that is not supported by your *Note `mysqld': mysqld. server (or
that was disabled with a startup option). If *Note `mysqld': mysqld.
doesn't support a storage engine, it instead creates the table as a
`MyISAM' table, which is nontransactional.

You can check the storage engine for a table by using either of these
statements:

SHOW TABLE STATUS LIKE 'TBL_NAME';
SHOW CREATE TABLE TBL_NAME;

See *Note show-table-status::, and *Note show-create-table::.

You can check which storage engines your *Note `mysqld': mysqld. server
supports by using this statement:

SHOW ENGINES;

You can also use the following statement, and check the value of the
variable that is associated with the storage engine in which you are
interested:

SHOW VARIABLES LIKE 'have_%';

For example, to determine whether the `InnoDB' storage engine is
available, check the value of the `have_innodb' variable.

See *Note show-engines::, and *Note show-variables::.

File: manual.info, Node: deleting-from-related-tables, Next: no-matching-rows, Prev: non-transactional-tables, Up: query-issues

C.5.5.6 Deleting Rows from Related Tables
.........................................

If the total length of the *Note `DELETE': delete. statement for
`related_table' is more than 1MB (the default value of the
`max_allowed_packet' system variable), you should split it into smaller
parts and execute multiple *Note `DELETE': delete. statements. You
probably get the fastest *Note `DELETE': delete. by specifying only
100 to 1,000 `related_column' values per statement if the
`related_column' is indexed. If the `related_column' isn't indexed, the
speed is independent of the number of arguments in the `IN' clause.

File: manual.info, Node: no-matching-rows, Next: problems-with-float, Prev: deleting-from-related-tables, Up: query-issues

C.5.5.7 Solving Problems with No Matching Rows
..............................................

If you have a complicated query that uses many tables but that doesn't
return any rows, you should use the following procedure to find out
what is wrong:

1. Test the query with *Note `EXPLAIN': explain. to check whether
you can find something that is obviously wrong. See *Note
explain::.

2. Select only those columns that are used in the `WHERE' clause.

3. Remove one table at a time from the query until it returns some
rows. If the tables are large, it is a good idea to use `LIMIT 10'
with the query.

4. Issue a *Note `SELECT': select. for the column that should have
matched a row against the table that was last removed from the
query.

5. If you are comparing *Note `FLOAT': numeric-types. or *Note
`DOUBLE': numeric-types. columns with numbers that have decimals,
you can't use equality (`=') comparisons. This problem is common
in most computer languages because not all floating-point values
can be stored with exact precision. In some cases, changing the
*Note `FLOAT': numeric-types. to a *Note `DOUBLE': numeric-types.
fixes this. See *Note problems-with-float::.

Similar problems may be encountered when comparing *Note
`DECIMAL': numeric-types. values prior to MySQL 5.0.3.

6. If you still can't figure out what is wrong, create a minimal test
that can be run with `mysql test < query.sql' that shows your
problems. You can create a test file by dumping the tables with
*Note `mysqldump --quick db_name TBL_NAME_1 ... TBL_NAME_N >
query.sql': mysqldump. Open the file in an editor, remove some
insert lines (if there are more than needed to demonstrate the
problem), and add your *Note `SELECT': select. statement at the end
of the file.

Verify that the test file demonstrates the problem by executing
these commands:

shell> mysqladmin create test2
shell> mysql test2 < query.sql

Attach the test file to a bug report, which you can file using the
instructions in *Note bug-reports::.

File: manual.info, Node: problems-with-float, Prev: no-matching-rows, Up: query-issues

C.5.5.8 Problems with Floating-Point Values
...........................................

Floating-point numbers sometimes cause confusion because they are
approximate and not stored as exact values. A floating-point value as
written in an SQL statement may not be the same as the value
represented internally. Attempts to treat floating-point values as
exact in comparisons may lead to problems. They are also subject to
platform or implementation dependencies. The *Note `FLOAT':
numeric-types. and *Note `DOUBLE': numeric-types. data types are subject
to these issues. Before MySQL 5.0.3, *Note `DECIMAL': numeric-types.
comparison operations are approximate as well.

Prior to MySQL 5.0.3, *Note `DECIMAL': numeric-types. columns store
values with exact precision because they are represented as strings,
but calculations on *Note `DECIMAL': numeric-types. values are done
using floating-point operations. As of 5.0.6, MySQL performs *Note
`DECIMAL': numeric-types. operations with a precision of 65 decimal
digits (64 digits from 5.0.3 to 5.0.5), which should solve most common
inaccuracy problems when it comes to *Note `DECIMAL': numeric-types.
columns. (If your server is from MySQL 5.0.3 or higher, but you have
*Note `DECIMAL': numeric-types. columns in tables that were created
before 5.0.3, the old behavior still applies to those columns. To
convert the tables to the newer *Note `DECIMAL': numeric-types. format,
dump them with *Note `mysqldump': mysqldump. and reload them.)

The following example (for versions of MySQL older than 5.0.3)
demonstrates the problem. It shows that even for older *Note `DECIMAL':
numeric-types. columns, calculations that are done using floating-point
operations are subject to floating-point error. (Were you to replace the
*Note `DECIMAL': numeric-types. columns with *Note `FLOAT':
numeric-types, similar problems would occur for all versions of MySQL.)

mysql> CREATE TABLE t1 (i INT, d1 DECIMAL(9,2), d2 DECIMAL(9,2));
mysql> INSERT INTO t1 VALUES (1, 101.40, 21.40), (1, -80.00, 0.00),
-> (2, 0.00, 0.00), (2, -13.20, 0.00), (2, 59.60, 46.40),
-> (2, 30.40, 30.40), (3, 37.00, 7.40), (3, -29.60, 0.00),
-> (4, 60.00, 15.40), (4, -10.60, 0.00), (4, -34.00, 0.00),
-> (5, 33.00, 0.00), (5, -25.80, 0.00), (5, 0.00, 7.20),
-> (6, 0.00, 0.00), (6, -51.40, 0.00);

mysql> SELECT i, SUM(d1) AS a, SUM(d2) AS b
-> FROM t1 GROUP BY i HAVING a <> b;
+------+--------+-------+
| i | a | b |
+------+--------+-------+
| 1 | 21.40 | 21.40 |
| 2 | 76.80 | 76.80 |
| 3 | 7.40 | 7.40 |
| 4 | 15.40 | 15.40 |
| 5 | 7.20 | 7.20 |
| 6 | -51.40 | 0.00 |
+------+--------+-------+

The result is correct. Although the first five records look like they
should not satisfy the comparison (the values of `a' and `b' do not
appear to be different), they may do so because the difference between
the numbers shows up around the tenth decimal or so, depending on
factors such as computer architecture or the compiler version or
optimization level. For example, different CPUs may evaluate
floating-point numbers differently.

As of MySQL 5.0.3, you will get only the last row in the above result.

The problem cannot be solved by using `ROUND()' or similar functions,
because the result is still a floating-point number:

mysql> SELECT i, ROUND(SUM(d1), 2) AS a, ROUND(SUM(d2), 2) AS b
-> FROM t1 GROUP BY i HAVING a <> b;
+------+--------+-------+
| i | a | b |
+------+--------+-------+
| 1 | 21.40 | 21.40 |
| 2 | 76.80 | 76.80 |
| 3 | 7.40 | 7.40 |
| 4 | 15.40 | 15.40 |
| 5 | 7.20 | 7.20 |
| 6 | -51.40 | 0.00 |
+------+--------+-------+

This is what the numbers in column `a' look like when displayed with
more decimal places:

mysql> SELECT i, ROUND(SUM(d1), 2)*1.0000000000000000 AS a,
-> ROUND(SUM(d2), 2) AS b FROM t1 GROUP BY i HAVING a <> b;
+------+----------------------+-------+
| i | a | b |
+------+----------------------+-------+
| 1 | 21.3999999999999986 | 21.40 |
| 2 | 76.7999999999999972 | 76.80 |
| 3 | 7.4000000000000004 | 7.40 |
| 4 | 15.4000000000000004 | 15.40 |
| 5 | 7.2000000000000002 | 7.20 |
| 6 | -51.3999999999999986 | 0.00 |
+------+----------------------+-------+

Depending on your computer architecture, you may or may not see similar
results. For example, on some machines you may get the `correct'
results by multiplying both arguments by 1, as the following example
shows.

*Warning*:

Never use this method in your applications. It is not an example of a
trustworthy method!

mysql> SELECT i, ROUND(SUM(d1), 2)*1 AS a, ROUND(SUM(d2), 2)*1 AS b
-> FROM t1 GROUP BY i HAVING a <> b;
+------+--------+------+
| i | a | b |
+------+--------+------+
| 6 | -51.40 | 0.00 |
+------+--------+------+

The reason that the preceding example seems to work is that on the
particular machine where the test was done, CPU floating-point
arithmetic happens to round the numbers to the same value. However,
there is no rule that any CPU should do so, so this method cannot be
trusted.

The correct way to do floating-point number comparison is to first
decide on an acceptable tolerance for differences between the numbers
and then do the comparison against the tolerance value. For example, if
we agree that floating-point numbers should be regarded the same if
they are same within a precision of one in ten thousand (0.0001), the
comparison should be written to find differences larger than the
tolerance value:

mysql> SELECT i, SUM(d1) AS a, SUM(d2) AS b FROM t1
-> GROUP BY i HAVING ABS(a - b) > 0.0001;
+------+--------+------+
| i | a | b |
+------+--------+------+
| 6 | -51.40 | 0.00 |
+------+--------+------+
1 row in set (0.00 sec)

Conversely, to get rows where the numbers are the same, the test should
find differences within the tolerance value:

mysql> SELECT i, SUM(d1) AS a, SUM(d2) AS b FROM t1
-> GROUP BY i HAVING ABS(a - b) <= 0.0001;
+------+-------+-------+
| i | a | b |
+------+-------+-------+
| 1 | 21.40 | 21.40 |
| 2 | 76.80 | 76.80 |
| 3 | 7.40 | 7.40 |
| 4 | 15.40 | 15.40 |
| 5 | 7.20 | 7.20 |
+------+-------+-------+

Floating-point values are subject to platform or implementation
dependencies. Suppose that you execute the following statements:

CREATE TABLE t1(c1 FLOAT(53,0), c2 FLOAT(53,0));
INSERT INTO t1 VALUES('1e+52','-1e+52');
SELECT * FROM t1;

On some platforms, the `SELECT' statement returns `inf' and `-inf'.
Other others, it returns `0' and `-0'.

An implication of the preceding issues is that if you attempt to create
a replication slave by dumping table contents with *Note `mysqldump':
mysqldump. on the master and reloading the dump file into the slave,
tables containing floating-point columns might differ between the two
hosts.

File: manual.info, Node: optimizer-issues, Next: table-definition-issues, Prev: query-issues, Up: problems

C.5.6 Optimizer-Related Issues
------------------------------

MySQL uses a cost-based optimizer to determine the best way to resolve
a query. In many cases, MySQL can calculate the best possible query
plan, but sometimes MySQL doesn't have enough information about the
data at hand and has to make `educated' guesses about the data.

For the cases when MySQL does not do the "right" thing, tools that you
have available to help MySQL are:

* Use the *Note `EXPLAIN': explain. statement to get information
about how MySQL processes a query. To use it, just add the keyword
*Note `EXPLAIN': explain. to the front of your *Note `SELECT':
select. statement:

mysql> EXPLAIN SELECT * FROM t1, t2 WHERE t1.i = t2.i;

*Note `EXPLAIN': explain. is discussed in more detail in *Note
explain::.

* Use `ANALYZE TABLE TBL_NAME' to update the key distributions for
the scanned table. See *Note analyze-table::.

* Use `FORCE INDEX' for the scanned table to tell MySQL that table
scans are very expensive compared to using the given index:

SELECT * FROM t1, t2 FORCE INDEX (index_for_column)
WHERE t1.col_name=t2.col_name;

`USE INDEX' and `IGNORE INDEX' may also be useful. See *Note
index-hints::.

* Global and table-level `STRAIGHT_JOIN'. See *Note select::.

* You can tune global or thread-specific system variables. For
example, Start *Note `mysqld': mysqld. with the
`--max-seeks-for-key=1000' option or use `SET
max_seeks_for_key=1000' to tell the optimizer to assume that no
key scan causes more than 1,000 key seeks. See *Note
server-system-variables::.

File: manual.info, Node: table-definition-issues, Next: bugs, Prev: optimizer-issues, Up: problems

C.5.7 Table Definition-Related Issues
-------------------------------------

* Menu:

* alter-table-problems:: Problems with `ALTER TABLE'
* temporary-table-problems:: `TEMPORARY' Table Problems

File: manual.info, Node: alter-table-problems, Next: temporary-table-problems, Prev: table-definition-issues, Up: table-definition-issues

C.5.7.1 Problems with `ALTER TABLE'
...................................

If you get a duplicate-key error when using *Note `ALTER TABLE':
alter-table. to change the character set or collation of a character
column, the cause is either that the new column collation maps two keys
to the same value or that the table is corrupted. In the latter case,
you should run *Note `REPAIR TABLE': repair-table. on the table.

If *Note `ALTER TABLE': alter-table. dies with the following error, the
problem may be that MySQL crashed during an earlier *Note `ALTER
TABLE': alter-table. operation and there is an old table named `A-XXX'
or `B-XXX' lying around:

Error on rename of './database/name.frm'
to './database/B-XXX.frm' (Errcode: 17)

In this case, go to the MySQL data directory and delete all files that
have names starting with `A-' or `B-'. (You may want to move them
elsewhere instead of deleting them.)

*Note `ALTER TABLE': alter-table. works in the following way:

* Create a new table named `A-XXX' with the requested structural
changes.

* Copy all rows from the original table to `A-XXX'.

* Rename the original table to `B-XXX'.

* Rename `A-XXX' to your original table name.

* Delete `B-XXX'.

If something goes wrong with the renaming operation, MySQL tries to
undo the changes. If something goes seriously wrong (although this
shouldn't happen), MySQL may leave the old table as `B-XXX'. A simple
rename of the table files at the system level should get your data back.

If you use *Note `ALTER TABLE': alter-table. on a transactional table
or if you are using Windows or OS/2, *Note `ALTER TABLE': alter-table.
unlocks the table if you had done a *Note `LOCK TABLE': lock-tables. on
it. This is done because `InnoDB' and these operating systems cannot
drop a table that is in use.

File: manual.info, Node: temporary-table-problems, Prev: alter-table-problems, Up: table-definition-issues

C.5.7.2 `TEMPORARY' Table Problems
..................................

The following list indicates limitations on the use of `TEMPORARY'
tables:

* A `TEMPORARY' table can only be of type `MEMORY', `MyISAM',
`MERGE', or `InnoDB'.

Temporary tables are not supported for MySQL Cluster.

* You cannot refer to a `TEMPORARY' table more than once in the same
query. For example, the following does not work:

mysql> SELECT * FROM temp_table, temp_table AS t2;
ERROR 1137: Can't reopen table: 'temp_table'

This error also occurs if you refer to a temporary table multiple
times in a stored function under different aliases, even if the
references occur in different statements within the function.

* The *Note `SHOW TABLES': show-tables. statement does not list
`TEMPORARY' tables.

* You cannot use `RENAME' to rename a `TEMPORARY' table. However,
you can use *Note `ALTER TABLE': alter-table. instead:

mysql> ALTER TABLE orig_name RENAME new_name;

* There are known issues in using temporary tables with replication.
See *Note replication-features::, for more information.

File: manual.info, Node: bugs, Prev: table-definition-issues, Up: problems

C.5.8 Known Issues in MySQL
---------------------------

This section lists known issues in recent versions of MySQL.

For information about platform-specific issues, see the installation
and porting instructions in *Note operating-system-specific-notes::, and
MySQL Internals: Porting
(http://forge.mysql.com/wiki/MySQL_Internals_Porting).

The following problems are known:

* Subquery optimization for `IN' is not as effective as for `='.

* Even if you use `lower_case_table_names=2' (which enables MySQL to
remember the case used for databases and table names), MySQL does
not remember the case used for database names for the function
`DATABASE()' or within the various logs (on case-insensitive
systems).

* Dropping a `FOREIGN KEY' constraint doesn't work in replication
because the constraint may have another name on the slave.

* *Note `REPLACE': replace. (and *Note `LOAD DATA': load-data. with
the *Note `REPLACE': replace. option) does not trigger `ON DELETE
CASCADE'.

* `DISTINCT' with `ORDER BY' doesn't work inside `GROUP_CONCAT()' if
you don't use all and only those columns that are in the
`DISTINCT' list.

* If one user has a long-running transaction and another user drops
a table that is updated in the transaction, there is small chance
that the binary log may contain the *Note `DROP TABLE':
drop-table. statement before the table is used in the transaction
itself. We plan to fix this by having the *Note `DROP TABLE':
drop-table. statement wait until the table is not being used in
any transaction.

* When inserting a big integer value (between 2^63 and 2^64-1) into
a decimal or string column, it is inserted as a negative value
because the number is evaluated in a signed integer context.

* *Note `FLUSH TABLES WITH READ LOCK': flush. does not block *Note
`COMMIT': commit. if the server is running without binary logging,
which may cause a problem (of consistency between tables) when
doing a full backup.

* *Note `ANALYZE TABLE': analyze-table. on a `BDB' table may in some
cases make the table unusable until you restart *Note `mysqld':
mysqld. If this happens, look for errors of the following form in
the MySQL error file:

001207 22:07:56 bdb: log_flush: LSN past current end-of-log

* Don't execute *Note `ALTER TABLE': alter-table. on a `BDB' table
on which you are running multiple-statement transactions until all
those transactions complete. (The transaction might be ignored.)

* *Note `ANALYZE TABLE': analyze-table, *Note `OPTIMIZE TABLE':
optimize-table, and *Note `REPAIR TABLE': repair-table. may cause
problems on tables for which you are using *Note `INSERT DELAYED':
insert-delayed.

* Performing `LOCK TABLE ...' and `FLUSH TABLES ...' doesn't
guarantee that there isn't a half-finished transaction in progress
on the table.

* `BDB' tables are relatively slow to open. If you have many `BDB'
tables in a database, it takes a long time to use the *Note
`mysql': mysql. client on the database if you are not using the
`-A' option or if you are using `rehash'. This is especially
noticeable when you have a large table cache.

* Replication uses query-level logging: The master writes the
executed queries to the binary log. This is a very fast, compact,
and efficient logging method that works perfectly in most cases.

It is possible for the data on the master and slave to become
different if a query is designed in such a way that the data
modification is nondeterministic (generally not a recommended
practice, even outside of replication).

For example:

* *Note `CREATE TABLE ... SELECT': create-table-select. or
*Note `INSERT ... SELECT': insert-select. statements that
insert zero or `NULL' values into an `AUTO_INCREMENT' column.

* *Note `DELETE': delete. if you are deleting rows from a table
that has foreign keys with `ON DELETE CASCADE' properties.

* *Note `REPLACE ... SELECT': replace, `INSERT IGNORE ...
SELECT' if you have duplicate key values in the inserted data.

*If and only if the preceding queries have no `ORDER BY' clause
guaranteeing a deterministic order*.

For example, for *Note `INSERT ... SELECT': insert-select. with no
`ORDER BY', the *Note `SELECT': select. may return rows in a
different order (which results in a row having different ranks,
hence getting a different number in the `AUTO_INCREMENT' column),
depending on the choices made by the optimizers on the master and
slave.

A query is optimized differently on the master and slave only if:

* The table is stored using a different storage engine on the
master than on the slave. (It is possible to use different
storage engines on the master and slave. For example, you can
use `InnoDB' on the master, but `MyISAM' on the slave if the
slave has less available disk space.)

* MySQL buffer sizes (`key_buffer_size', and so on) are
different on the master and slave.

* The master and slave run different MySQL versions, and the
optimizer code differs between these versions.

This problem may also affect database restoration using
`mysqlbinlog|mysql'.

The easiest way to avoid this problem is to add an `ORDER BY'
clause to the aforementioned nondeterministic queries to ensure
that the rows are always stored or modified in the same order.

In future MySQL versions, we will automatically add an `ORDER BY'
clause when needed.

The following issues are known and will be fixed in due time:

* Log file names are based on the server host name (if you don't
specify a file name with the startup option). You have to use
options such as `--log-bin=OLD_HOST_NAME-bin' if you change your
host name to something else. Another option is to rename the old
files to reflect your host name change (if these are binary logs,
you need to edit the binary log index file and fix the binary log
file names there as well). See *Note server-options::.

* *Note `mysqlbinlog': mysqlbinlog. does not delete temporary files
left after a *Note `LOAD DATA INFILE': load-data. statement. See
*Note mysqlbinlog::.

* `RENAME' doesn't work with `TEMPORARY' tables or tables used in a
`MERGE' table.

* Due to the way table format (`.frm') files are stored, you cannot
use character 255 (`CHAR(255)') in table names, column names, or
enumerations. This is scheduled to be fixed in version 5.1 when we
implement new table definition format files.

* When using `SET CHARACTER SET', you can't use translated
characters in database, table, and column names.

* You can't use ``_'' or ``%'' with `ESCAPE' in `LIKE ... ESCAPE'.

* *Note `BLOB': blob. and *Note `TEXT': blob. values can't reliably
be used in `GROUP BY', `ORDER BY' or `DISTINCT'. Only the first
`max_sort_length' bytes are used when comparing *Note `BLOB': blob.
values in these cases. The default value of `max_sort_length' is
1024 and can be changed at server startup time or at runtime.

* Numeric calculations are done with *Note `BIGINT': numeric-types.
or *Note `DOUBLE': numeric-types. (both are normally 64 bits
long). Which precision you get depends on the function. The
general rule is that bit functions are performed with *Note
`BIGINT': numeric-types. precision, `IF()' and `ELT()' with *Note
`BIGINT': numeric-types. or *Note `DOUBLE': numeric-types.
precision, and the rest with *Note `DOUBLE': numeric-types.
precision. You should try to avoid using unsigned long long
values if they resolve to be larger than 63 bits
(9223372036854775807) for anything other than bit fields.

* You can have up to 255 *Note `ENUM': enum. and *Note `SET': set.
columns in one table.

* In `MIN()', `MAX()', and other aggregate functions, MySQL
currently compares *Note `ENUM': enum. and *Note `SET': set.
columns by their string value rather than by the string's relative
position in the set.

* *Note `mysqld_safe': mysqld-safe. redirects all messages from
*Note `mysqld': mysqld. to the *Note `mysqld': mysqld. log. One
problem with this is that if you execute *Note `mysqladmin
refresh': mysqladmin. to close and reopen the log, `stdout' and
`stderr' are still redirected to the old log. If you use the
general query log extensively, you should edit *Note
`mysqld_safe': mysqld-safe. to log to `HOST_NAME.err' instead of
`HOST_NAME.log' so that you can easily reclaim the space for the
old log by deleting it and executing *Note `mysqladmin refresh':
mysqladmin.

* In an *Note `UPDATE': update. statement, columns are updated from
left to right. If you refer to an updated column, you get the
updated value instead of the original value. For example, the
following statement increments `KEY' by `2', *not* `1':

mysql> UPDATE TBL_NAME SET KEY=KEY+1,KEY=KEY+1;

* You can refer to multiple temporary tables in the same query, but
you cannot refer to any given temporary table more than once. For
example, the following doesn't work:

mysql> SELECT * FROM temp_table, temp_table AS t2;
ERROR 1137: Can't reopen table: 'temp_table'

* The optimizer may handle `DISTINCT' differently when you are using
`hidden' columns in a join than when you are not. In a join,
hidden columns are counted as part of the result (even if they are
not shown), whereas in normal queries, hidden columns don't
participate in the `DISTINCT' comparison. We will probably change
this in the future to never compare the hidden columns when
executing `DISTINCT'.

An example of this is:

SELECT DISTINCT mp3id FROM band_downloads
WHERE userid = 9 ORDER BY id DESC;

and

SELECT DISTINCT band_downloads.mp3id
FROM band_downloads,band_mp3
WHERE band_downloads.userid = 9
AND band_mp3.id = band_downloads.mp3id
ORDER BY band_downloads.id DESC;

In the second case, using MySQL Server 3.23.x, you may get two
identical rows in the result set (because the values in the hidden
`id' column may differ).

Note that this happens only for queries where that do not have the
`ORDER BY' columns in the result.

* If you execute a `PROCEDURE' on a query that returns an empty set,
in some cases the `PROCEDURE' does not transform the columns.

* Creation of a table of type `MERGE' doesn't check whether the
underlying tables are compatible types.

* If you use *Note `ALTER TABLE': alter-table. to add a `UNIQUE'
index to a table used in a `MERGE' table and then add a normal
index on the `MERGE' table, the key order is different for the
tables if there was an old, non-`UNIQUE' key in the table. This is
because *Note `ALTER TABLE': alter-table. puts `UNIQUE' indexes
before normal indexes to be able to detect duplicate keys as early
as possible.

File: manual.info, Node: news, Next: restrictions, Prev: error-handling, Up: Top

Appendix D MySQL Change History
*******************************

* Menu:

* news-5-0-x:: Changes in Release 5.0.x (Production)
* mysql-cluster-change-history:: Changes in MySQL Cluster
* mem-news:: MySQL Enterprise Monitor Change History
* connector-odbc-news:: MySQL Connector/ODBC (MyODBC) Change History
* connector-net-news:: MySQL Connector/NET Change History
* vstudio-plugin-news:: MySQL Visual Studio Plugin Change History
* cj-news:: MySQL Connector/J Change History
* news-connector-mxj:: MySQL Connector/MXJ Change History
* mysql-proxy-news:: MySQL Proxy Change History

This appendix lists the changes from version to version in the MySQL
source code through the latest version of MySQL 5.0, which is currently
MySQL 5.0.93. We offer a version of the Manual for each series of MySQL
releases (5.0, 5.1, and so forth). For information about changes in
another release series of the MySQL database software, see the
corresponding version of this Manual.

End of Product Lifecycle

We update this section as we add new features in the 5.0 series, so
that everybody can follow the development process.

This section documents all enhancements, changes, and bug fixes made to
MySQL Enterprise Server and MySQL Community Server.

Releases in MySQL Enterprise Server are divided into the following
release packs:

* _Rapid Update Service Packs_ are issued once a month and
incorporate all the bug fixes and security updates introduced
since the previous MySQL Enterprise Server release. A single
Service Pack can be used to update MySQL Enterprise Server; it is
not necessary to install intervening service packs to bring your
system up to date.

* _Quarterly Service Packs_ are issued each quarter and incorporate
all the bug fixes and security updates introduced up to the Rapid
Update that the QSP it is based on, and possibly some critical bug
fixes and security updates from later releases. A single Service
Pack can be used to update MySQL Enterprise Server; it is not
necessary to install intervening service packs to bring your
system up to date.

* _Hot-fix releases_ incorporate fixes for bugs that caused
significant issues that are not released as part of a Service Pack.

Note that we tend to update the manual at the same time we make changes
to MySQL. If you find a recent version of MySQL listed here that you
can't find on our download page (`http://dev.mysql.com/downloads/'), it
means that the version has not yet been released (and will normally be
marked so in the appropriate Release Note section).

The date mentioned with a release version is the date of the last
Bazaar commit on which the release was based, not the date when the
packages were made available. The binaries are usually made available a
few days after the date of the tagged ChangeSet, because building and
testing all packages takes some time.

For information on how to determine your current version and release
type, see *Note installation-version::.

The manual included in the source and binary distributions may not be
fully accurate when it comes to the release changelog entries, because
the integration of the manual happens at build time. For the most
up-to-date release changelog, please refer to the online version
instead.

File: manual.info, Node: news-5-0-x, Next: mysql-cluster-change-history, Prev: news, Up: news

D.1 Changes in Release 5.0.x (Production)
=========================================

* Menu:

* news-5-0-92:: Changes in MySQL 5.0.92 (Not yet released)
* news-5-0-91:: Changes in MySQL 5.0.91 (05 May 2010)
* news-5-0-90:: Changes in MySQL 5.0.90 (15 January 2010)
* news-5-0-89:: Changes in MySQL 5.0.89 (02 December 2009)
* news-5-0-88:: Changes in MySQL 5.0.88 (04 November 2009)
* news-5-0-87sp1:: Release Notes for MySQL Enterprise 5.0.87sp1 [QSP] (03 February 2010)
* news-5-0-87:: Changes in MySQL 5.0.87 (15 October 2009)
* news-5-0-86:: Changes in MySQL 5.0.86 (09 September 2009)
* news-5-0-85:: Changes in MySQL 5.0.85 (11 August 2009)
* news-5-0-84sp1:: Release Notes for MySQL Enterprise 5.0.84sp1 [QSP] (30 September 2009)
* news-5-0-84:: Changes in MySQL 5.0.84 (07 July 2009)
* news-5-0-83:: Changes in MySQL 5.0.83 (29 May 2009)
* news-5-0-82sp1:: Release Notes for MySQL Enterprise 5.0.82sp1 [QSP] (21 July 2009)
* news-5-0-82:: Changes in MySQL 5.0.82 (20 May 2009)
* news-5-0-81:: Release Notes for MySQL Community Server 5.0.81 (01 May 2009)
* news-5-0-80:: Release Notes for MySQL Enterprise 5.0.80 [MRU] (01 May 2009)
* news-5-0-79:: Release Notes for MySQL Enterprise 5.0.79 [MRU] (09 March 2009)
* news-5-0-78:: Release Notes for MySQL Enterprise 5.0.78 [MRU] (06 February 2009)
* news-5-0-77:: Release Notes for MySQL Community Server 5.0.77 (28 January 2009)
* news-5-0-76:: Release Notes for MySQL Enterprise 5.0.76 [MRU] (05 January 2009)
* news-5-0-75:: Release Notes for MySQL Community Server 5.0.75 (17 December 2008)
* news-5-0-74sp1:: Release Notes for MySQL Enterprise 5.0.74sp1 [QSP] (30 April 2009)
* news-5-0-74:: Release Notes for MySQL Enterprise 5.0.74 [MRU] (03 December 2008)
* news-5-0-72sp1:: Release Notes for MySQL Enterprise 5.0.72sp1 [QSP] (13 January 2009)
* news-5-0-72:: Release Notes for MySQL Enterprise 5.0.72 [MRU] (24 October 2008)
* news-5-0-70:: Release Notes for MySQL Enterprise 5.0.70 [MRU] (27 September 2008)
* news-5-0-68:: Release Notes for MySQL Enterprise 5.0.68 [MRU] (13 August 2008)
* news-5-0-67:: Release Notes for MySQL Community Server 5.0.67 (04 August 2008)
* news-5-0-66sp1:: Release Notes for MySQL Enterprise 5.0.66sp1 [QSP] (23 October 2008)
* news-5-0-66a:: Release Notes for MySQL Enterprise 5.0.66a [MRU] (16 July 2008)
* news-5-0-66:: Release Notes for MySQL Enterprise 5.0.66 [MRU] (09 July 2008)
* news-5-0-64:: Release Notes for MySQL Enterprise 5.0.64 [MRU] (10 June 2008)
* news-5-0-62:: Release Notes for MySQL Enterprise 5.0.62 [MRU] (12 May 2008)
* news-5-0-60sp1:: Release Notes for MySQL Enterprise 5.0.60sp1 [QSP] (27 June 2008)
* news-5-0-60:: Release Notes for MySQL Enterprise 5.0.60 [MRU] (28 April 2008)
* news-5-0-58:: Release Notes for MySQL Enterprise 5.0.58 [MRU] (05 March 2008)
* news-5-0-56sp1:: Release Notes for MySQL Enterprise 5.0.56sp1 [QSP] (30 March 2008)
* news-5-0-56:: Release Notes for MySQL Enterprise 5.0.56 [MRU] (06 February 2008)
* news-5-0-54a:: Release Notes for MySQL Enterprise 5.0.54a [MRU] (11 January 2008)
* news-5-0-54:: Release Notes for MySQL Enterprise 5.0.54 [MRU] (14 December 2007)
* news-5-0-52:: Release Notes for MySQL Enterprise 5.0.52 [MRU] (30 November 2007)
* news-5-0-51b:: Release Notes for MySQL Community Server 5.0.51b (24 April 2008)
* news-5-0-51a:: Release Notes for MySQL Community Server 5.0.51a (11 January 2008)
* news-5-0-51:: Release Notes for MySQL Community Server 5.0.51 (15 November 2007)
* news-5-0-50sp1a:: Release Notes for MySQL Enterprise 5.0.50sp1a [QSP] (11 January 2008)
* news-5-0-50sp1:: Release Notes for MySQL Enterprise 5.0.50sp1 [QSP] (12 December 2007)
* news-5-0-50:: Release Notes for MySQL Enterprise 5.0.50 [MRU] (19 October 2007)
* news-5-0-48:: Release Notes for MySQL Enterprise 5.0.48 [MRU] (27 August 2007)
* news-5-0-46:: Release Notes for MySQL Enterprise 5.0.46 [MRU] (13 July 2007)
* news-5-0-45:: Release Notes for MySQL Community Server 5.0.45 (04 July 2007)
* news-5-0-44sp1:: Release Notes for MySQL Enterprise 5.0.44sp1 [QSP] (01 August 2007)
* news-5-0-44:: Release Notes for MySQL Enterprise 5.0.44 [MRU] (21 June 2007)
* news-5-0-42:: Release Notes for MySQL Enterprise 5.0.42 [MRU] (23 May 2007)
* news-5-0-41:: Release Notes for MySQL Community Server 5.0.41 (01 May 2007)
* news-5-0-40:: Release Notes for MySQL Enterprise 5.0.40 [MRU] (17 April 2007)
* news-5-0-38:: Release Notes for MySQL Enterprise 5.0.38 [MRU] (20 March 2007)
* news-5-0-37:: Release Notes for MySQL Community Server 5.0.37 (27 February 2007)
* news-5-0-36sp1:: Release Notes for MySQL Enterprise 5.0.36sp1 [QSP] (12 April 2007)
* news-5-0-36:: Release Notes for MySQL Enterprise 5.0.36 [MRU] (20 February 2007)
* news-5-0-34:: Release Notes for MySQL Enterprise 5.0.34 [MRU] (17 January 2007)
* news-5-0-33:: Release Notes for MySQL Community Server 5.0.33 (09 January 2007)
* news-5-0-32:: Release Notes for MySQL Enterprise 5.0.32 [MRU] (20 December 2006)
* news-5-0-30sp1:: Release Notes for MySQL Enterprise 5.0.30sp1 [QSP] (19 January 2007)
* news-5-0-30:: Release Notes for MySQL Enterprise 5.0.30 [MRU] (14 November 2006)
* news-5-0-28:: Release Notes for MySQL Enterprise 5.0.28 (24 October 2006)
* news-5-0-27:: Release Notes for MySQL Community Server 5.0.27 (21 October 2006)
* news-5-0-26:: Changes in MySQL 5.0.26 (03 October 2006)
* news-5-0-25:: Changes in MySQL 5.0.25 (15 September 2006)
* news-5-0-24a:: Changes in MySQL 5.0.24a (25 August 2006)
* news-5-0-24:: Changes in MySQL 5.0.24 (27 July 2006)
* news-5-0-23:: Changes in MySQL 5.0.23 (Not released)
* news-5-0-22:: Changes in MySQL 5.0.22 (24 May 2006)
* news-5-0-21:: Changes in MySQL 5.0.21 (02 May 2006)
* news-5-0-20a:: Changes in MySQL 5.0.20a (18 April 2006)
* news-5-0-20:: Changes in MySQL 5.0.20 (31 March 2006)
* news-5-0-19:: Changes in MySQL 5.0.19 (04 March 2006)
* news-5-0-18:: Changes in MySQL 5.0.18 (21 December 2005)
* news-5-0-17:: Changes in MySQL 5.0.17 (14 December 2005)
* news-5-0-16:: Changes in MySQL 5.0.16 (10 November 2005)
* news-5-0-15:: Changes in MySQL 5.0.15 (19 October 2005 Production)
* news-5-0-14:: Changes in MySQL 5.0.14 (Not released)
* news-5-0-13:: Changes in MySQL 5.0.13 (22 September 2005 Release Candidate)
* news-5-0-12:: Changes in MySQL 5.0.12 (02 September 2005)
* news-5-0-11:: Changes in MySQL 5.0.11 (06 August 2005)
* news-5-0-10:: Changes in MySQL 5.0.10 (27 July 2005)
* news-5-0-9:: Changes in MySQL 5.0.9 (15 July 2005)
* news-5-0-8:: Changes in MySQL 5.0.8 (Not released)
* news-5-0-7:: Changes in MySQL 5.0.7 (10 June 2005)
* news-5-0-6:: Changes in MySQL 5.0.6 (26 May 2005)
* news-5-0-5:: Changes in MySQL 5.0.5 (Not released)
* news-5-0-4:: Changes in MySQL 5.0.4 (16 April 2005)
* news-5-0-3:: Changes in MySQL 5.0.3 (23 March 2005 Beta)
* news-5-0-2:: Changes in MySQL 5.0.2 (01 December 2004)
* news-5-0-1:: Changes in MySQL 5.0.1 (27 July 2004)
* news-5-0-0:: Changes in MySQL 5.0.0 (22 December 2003 Alpha)

End of Product Lifecycle

An overview of features added in MySQL 5.0 can be found here: *Note
mysql-nutshell::.

The following list summarizes what has been done in MySQL 5.0. For a
full list of changes, please refer to the changelog sections for
individual 5.0 releases.

For discussion of upgrade issues that you may encounter for upgrades
from MySQL 4.1 to MySQL 5.0, see *Note upgrading-from-previous-series::.

* *Note `VARCHAR': char. and *Note `VARBINARY': binary-varbinary.
columns retain trailing spaces. A `VARCHAR()' or *Note
`VARBINARY': binary-varbinary. column can contain up to 65,535
characters or bytes, respectively.

* Strict SQL mode, which causes an error instead of a warning when
inserting an incorrect value into a column. See *Note
server-sql-mode::.

* A new fixed-point math library supports precision math, resulting
in more accurate results when working with the *Note `DECIMAL':
numeric-types. and *Note `NUMERIC': numeric-types. data types. For
details, see *Note precision-math::.

* Basic support for views. See *Note views::.

* Basic support for stored procedures and functions (SQL:2003
style). See *Note stored-routines::.

* Basic support for triggers. See *Note triggers::.

* Basic support for read-only server side cursors. For information
about using cursors within stored routines, see *Note cursors::.
For information about using cursors from within the C API, see
*Note mysql-stmt-attr-set::.

* Support for `SELECT INTO LIST_OF_VARS', where the variables can be
a mix of global and local types. See *Note select-into-statement::.

* `MEMORY' (`HEAP') tables can have *Note `VARCHAR': char. columns.

* When using a constant string or a function that generates a string
result in `CREATE ... SELECT', MySQL creates the result column
based on the maximum length of the string or expression:

Maximum Length Data type
= 0 `CHAR(0)'
< 512 `VARCHAR(MAX_LENGTH)'
>= 512 *Note `TEXT': blob.

* Removed the update log. It is fully replaced by the binary log.
If the MySQL server is started with `--log-update', it is
translated to `--log-bin' (or ignored if the server is explicitly
started with `--log-bin'), and a warning message is written to the
error log. Setting `sql_log_update' silently sets `sql_log_bin'
instead (or do nothing if the server is explicitly started with
`--log-bin').

* Removed support for the `ISAM' storage engine. If you have `ISAM'
tables, you should convert them before upgrading. See *Note
upgrading-from-previous-series::.

* Removed support for `RAID' options in `MyISAM' tables. If you have
tables that use these options, you should convert them before
upgrading. See *Note upgrading-from-previous-series::.

File: manual.info, Node: news-5-0-92, Next: news-5-0-91, Prev: news-5-0-x, Up: news-5-0-x

D.1.1 Changes in MySQL 5.0.92 (Not yet released)
------------------------------------------------

End of Product Lifecycle

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.91). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Functionality added or changed:

* The time zone tables available at
`http://dev.mysql.com/downloads/timezones.html' have been updated.
These tables can be used on systems such as Windows or HP-UX that
do not include zoneinfo files. (Bug#40230
(http://bugs.mysql.com/bug.php?id=40230))

Bugs fixed:

* *Security Fix*: During evaluation of arguments to extreme-value
functions (such as `LEAST()' and `GREATEST()'), type errors did not
propagate properly, causing the server to crash. (Bug#55826
(http://bugs.mysql.com/bug.php?id=55826), CVE-2010-3833
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3833))

* *Security Fix*: The server could crash after materializing a
derived table that required a temporary table for grouping.
(Bug#55568 (http://bugs.mysql.com/bug.php?id=55568), CVE-2010-3834
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3834))

* *Security Fix*: A user-variable assignment expression that is
evaluated in a logical expression context can be precalculated in
a temporary table for `GROUP BY'. However, when the expression
value is used after creation of the temporary table, it was
re-evaluated, not read from the table and a server crash resulted.
(Bug#55564 (http://bugs.mysql.com/bug.php?id=55564), CVE-2010-3835
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3835))

* *Security Fix*: Joins involving a table with a unique *Note `SET':
set. column could cause a server crash. (Bug#54575
(http://bugs.mysql.com/bug.php?id=54575), CVE-2010-3677
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3677))

* *Security Fix*: Pre-evaluation of `LIKE' predicates during view
preparation could cause a server crash. (Bug#54568
(http://bugs.mysql.com/bug.php?id=54568), CVE-2010-3836
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3836))

* *Security Fix*: `GROUP_CONCAT()' and `WITH ROLLUP' together could
cause a server crash. (Bug#54476
(http://bugs.mysql.com/bug.php?id=54476), CVE-2010-3837
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3837))

* *Security Fix*: Queries could cause a server crash if the
`GREATEST()' or `LEAST()' function had a mixed list of numeric and
*Note `LONGBLOB': blob. arguments, and the result of such a
function was processed using an intermediate temporary table.
(Bug#54461 (http://bugs.mysql.com/bug.php?id=54461), CVE-2010-3838
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3838))

* *Security Fix*: Using *Note `EXPLAIN': explain. with queries of the
form `SELECT ... UNION ... ORDER BY (SELECT ... WHERE ...)' could
cause a server crash. (Bug#52711
(http://bugs.mysql.com/bug.php?id=52711), CVE-2010-3682
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3682))

* *InnoDB Storage Engine*: Creating or dropping a table with 1023
transactions active caused an assertion failure. (Bug#49238
(http://bugs.mysql.com/bug.php?id=49238))

* The `make_binary_distribution' target to `make' could fail on some
platforms because the lines generated were too long for the shell.
(Bug#54590 (http://bugs.mysql.com/bug.php?id=54590))

* A client could supply data in chunks to a prepared statement
parameter other than of type *Note `TEXT': blob. or *Note `BLOB':
blob. using the *Note `mysql_stmt_send_long_data()':
mysql-stmt-send-long-data. C API function (or
`COM_STMT_SEND_LONG_DATA' command). This led to a crash because
other data types are not valid for long data. (Bug#54041
(http://bugs.mysql.com/bug.php?id=54041))

* Builds of the embedded *Note `mysqld': mysqld. would fail due to a
missing element of the `struct NET'. (Bug#53908
(http://bugs.mysql.com/bug.php?id=53908), Bug#53912
(http://bugs.mysql.com/bug.php?id=53912))

* The definition of the `MY_INIT' macro in `my_sys.h' included an
extraneous semicolon, which could cause compilation failure.
(Bug#53906 (http://bugs.mysql.com/bug.php?id=53906))

* If the remote server for a *Note `FEDERATED':
federated-storage-engine. table could not be accessed, queries for
the *Note `INFORMATION_SCHEMA.TABLES': tables-table. table failed.
(Bug#35333 (http://bugs.mysql.com/bug.php?id=35333))

* *Note `mysqld': mysqld. could fail during execution when using SSL.
(Bug#34236 (http://bugs.mysql.com/bug.php?id=34236))

* Threads that were calculating the estimated number of records for
a range scan did not respond to the *Note `KILL': kill. statement.
That is, if a `range' join type is possible (even if not selected
by the optimizer as a join type of choice and thus not shown by
*Note `EXPLAIN': explain.), the query in the `statistics' state
(shown by the *Note `SHOW PROCESSLIST': show-processlist.) did not
respond to the *Note `KILL': kill. statement. (Bug#25421
(http://bugs.mysql.com/bug.php?id=25421))

File: manual.info, Node: news-5-0-91, Next: news-5-0-90, Prev: news-5-0-92, Up: news-5-0-x

D.1.2 Changes in MySQL 5.0.91 (05 May 2010)
-------------------------------------------

End of Product Lifecycle

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.90). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

icc Notes:
* This is the final release of MySQL 5.0 for which Generic Linux
MySQL binary packages built with the `icc' compiler on x86 and
x86_64 will be offered. These were previously produced as an
alternative to our main packages built using `gcc', as they
provided noticeable performance benefits. In recent times the
performance differences have diminished and build and runtime
problems have surfaced, thus it is no longer viable to continue
producing them.

We continue to use the `icc' compiler to produce our
distribution-specific RPM packages on ia64.

Bugs fixed:

* *Security Fix*: The server failed to check the table name argument
of a `COM_FIELD_LIST' command packet for validity and compliance
to acceptable table name standards. This could be exploited to
bypass almost all forms of checks for privileges and table-level
grants by providing a specially crafted table name argument to
`COM_FIELD_LIST'.

In MySQL 5.0 and above, this permitted an authenticated user with
`SELECT' privileges on one table to obtain the field definitions
of any table in all other databases and potentially of other MySQL
instances accessible from the server's file system.

Additionally, for MySQL version 5.1 and above, an authenticated
user with `DELETE' or `SELECT' privileges on one table could
delete or read content from any other table in all databases on
this server, and potentially of other MySQL instances accessible
from the server's file system. (Bug#53371
(http://bugs.mysql.com/bug.php?id=53371), CVE-2010-1848
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-1848))

* *Security Fix*: The server was susceptible to a buffer-overflow
attack due to a failure to perform bounds checking on the table
name argument of a `COM_FIELD_LIST' command packet. By sending
long data for the table name, a buffer is overflown, which could
be exploited by an authenticated user to inject malicious code.
(Bug#53237 (http://bugs.mysql.com/bug.php?id=53237), CVE-2010-1850
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-1850))

* *Security Fix*: The server could be tricked into reading packets
indefinitely if it received a packet larger than the maximum size
of one packet. (Bug#50974
(http://bugs.mysql.com/bug.php?id=50974), CVE-2010-1849
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-1849))

* The optimizer could attempt to evaluate the `WHERE' clause before
any rows had been read, resulting in a server crash. (Bug#52177
(http://bugs.mysql.com/bug.php?id=52177))

* On Windows, `LOAD_FILE()' could cause a crash for some pathnames.
(Bug#51893 (http://bugs.mysql.com/bug.php?id=51893))

* Use of *Note `HANDLER': handler. statements with tables that had
spatial indexes caused a server crash. (Bug#51357
(http://bugs.mysql.com/bug.php?id=51357))

* With an XA transaction active, *Note `SET autocommit = 1':
set-option. could cause side effects such as memory corruption or
a server crash. (Bug#51342
(http://bugs.mysql.com/bug.php?id=51342))

* The SSL certificates in the test suite were about to expire. They
have been updated with expiration dates in the year 2015.
(Bug#50642 (http://bugs.mysql.com/bug.php?id=50642))

* For debug builds, an assertion was incorrectly raised in the
optimizer when matching `ORDER BY' expressions. (Bug#50335
(http://bugs.mysql.com/bug.php?id=50335))

* The `filesort' sorting method applied to a *Note `CHAR(0)': char.
column could lead to a server crash. (Bug#49897
(http://bugs.mysql.com/bug.php?id=49897))

* `sql_buffer_result' had an effect on non-*Note `SELECT': select.
statements, contrary to the documentation. (Bug#49552
(http://bugs.mysql.com/bug.php?id=49552))

* *Note `EXPLAIN EXTENDED': explain. crashed trying to print column
names for a subquery in the `FROM' clause when the table had gone
out of scope. (Bug#49487 (http://bugs.mysql.com/bug.php?id=49487))

* `mysql-test-run.pl' now recognizes the `MTR_TESTCASE_TIMEOUT',
`MTR_SUITE_TIMEOUT', `MTR_SHUTDOWN_TIMEOUT', and
`MTR_START_TIMEOUT' environment variables. If they are set, their
values are used to set the `--testcase-timeout', `--suite-timeout',
`--shutdown-timeout', and `--start-timeout' options, respectively.
(Bug#49210 (http://bugs.mysql.com/bug.php?id=49210))

* Certain `INTERVAL' expressions could cause a crash on 64-bit
systems. (Bug#48739 (http://bugs.mysql.com/bug.php?id=48739))

* The server crashed when it could not determine the best execution
plan for queries involving outer joins with nondeterministic `ON'
clauses such as the ones containing the `RAND()' function, a
user-defined function, or a `NOT DETERMINISTIC' stored function.
(Bug#48483 (http://bugs.mysql.com/bug.php?id=48483))

* If an outer query was invalid, a subquery might not even be set
up. *Note `EXPLAIN EXTENDED': explain. did not expect this and
caused a crash by trying to dereference improperly set up
information. (Bug#48295 (http://bugs.mysql.com/bug.php?id=48295))

File: manual.info, Node: news-5-0-90, Next: news-5-0-89, Prev: news-5-0-91, Up: news-5-0-x

D.1.3 Changes in MySQL 5.0.90 (15 January 2010)
-----------------------------------------------

End of Product Lifecycle

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.89). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Security Fix*: For servers built with yaSSL, a preauthorization
buffer overflow could cause memory corruption or a server crash.
We thank Evgeny Legerov from Intevydis for providing us with a
proof-of-concept script that permitted us to reproduce this bug.
(Bug#50227 (http://bugs.mysql.com/bug.php?id=50227), CVE-2009-4484
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-4484))

* *Replication*: *Note `FLUSH LOGS': flush. did not close and reopen
the binary log index file. (Bug#48738
(http://bugs.mysql.com/bug.php?id=48738)) See also Bug#34582
(http://bugs.mysql.com/bug.php?id=34582).

* Some prepared statements could raise an assertion when re-executed.
(Bug#49570 (http://bugs.mysql.com/bug.php?id=49570))

* Valgrind warnings for *Note `CHECKSUM TABLE': checksum-table. were
corrected. (Bug#49465 (http://bugs.mysql.com/bug.php?id=49465))

* Specifying an index algorithm (such as `BTREE') for `SPATIAL' or
`FULLTEXT' indexes caused a server crash. These index types do not
support algorithm specification, and it is not longer permitted to
do so. (Bug#49250 (http://bugs.mysql.com/bug.php?id=49250))

* The optimizer sometimes incorrectly handled conditions of the form
`WHERE COL_NAME='CONST1' AND COL_NAME='CONST2''. (Bug#49199
(http://bugs.mysql.com/bug.php?id=49199))

* Several `strmake()' calls had an incorrect length argument (too
large by one). (Bug#48983
(http://bugs.mysql.com/bug.php?id=48983))

* On Fedora 12, `strmov()' did not guarantee correct operation for
overlapping source and destination buffer. Calls were fixed to
use an overlap-safe version instead. (Bug#48866
(http://bugs.mysql.com/bug.php?id=48866))

* Incomplete reset of internal `TABLE' structures could cause a
crash with `eq_ref' table access in subqueries. (Bug#48709
(http://bugs.mysql.com/bug.php?id=48709))

* Re-execution of a prepared statement could cause a server crash.
(Bug#48508 (http://bugs.mysql.com/bug.php?id=48508))

* The error message for `ER_UPDATE_INFO' was subject to buffer
overflow or truncation. (Bug#48500
(http://bugs.mysql.com/bug.php?id=48500))

* On Solaris, no stack trace was printed to the error log after a
crash. (Bug#47391 (http://bugs.mysql.com/bug.php?id=47391))

* A crash occurred when a user variable that was assigned to a
subquery result was used as a result field in a *Note `SELECT':
select. statement with aggregate functions. (Bug#47371
(http://bugs.mysql.com/bug.php?id=47371))

* Comparison with `NULL' values sometimes did not produce a correct
result. (Bug#42760 (http://bugs.mysql.com/bug.php?id=42760))

* When compressed *Note `MyISAM': myisam-storage-engine. files were
opened, they were always memory mapped, sometimes causing
memory-swapping problems. To deal with this, a new system
variable, `myisam_mmap_size', was added to limit the amount of
memory used for memory mapping of *Note `MyISAM':
myisam-storage-engine. files. (Bug#37408
(http://bugs.mysql.com/bug.php?id=37408))

File: manual.info, Node: news-5-0-89, Next: news-5-0-88, Prev: news-5-0-90, Up: news-5-0-x

D.1.4 Changes in MySQL 5.0.89 (02 December 2009)
------------------------------------------------

End of Product Lifecycle

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.88). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* Privileges for stored routines were ignored for mixed-case routine
names. (Bug#48872 (http://bugs.mysql.com/bug.php?id=48872)) See
also Bug#41049 (http://bugs.mysql.com/bug.php?id=41049).

* Building MySQL on Fedora Core 12 64-bit failed, due to errors in
*Note `comp_err': comp-err. (Bug#48864
(http://bugs.mysql.com/bug.php?id=48864))

* `DISTINCT' was ignored for queries with `GROUP BY WITH ROLLUP' and
only `const' tables. (Bug#48475
(http://bugs.mysql.com/bug.php?id=48475))

* Loose index scan was inappropriately chosen for some `WHERE'
conditions. (Bug#48472 (http://bugs.mysql.com/bug.php?id=48472))

* A bad typecast could cause query execution to allocate large
amounts of memory. (Bug#48458
(http://bugs.mysql.com/bug.php?id=48458))

* *Note `mysql_secure_installation': mysql-secure-installation. did
not work on Solaris. (Bug#48086
(http://bugs.mysql.com/bug.php?id=48086))

* When running *Note `mysql_secure_installation':
mysql-secure-installation, the command would fail if the root
password contained multiple spaces, \, # or quote characters.
(Bug#48031 (http://bugs.mysql.com/bug.php?id=48031))

* `InnoDB' did not disallow creation of an index with the name
`GEN_CLUST_INDEX', which is used internally. (Bug#46000
(http://bugs.mysql.com/bug.php?id=46000))

* Use of *Note `InnoDB': innodb-storage-engine. monitoring (*Note
`SHOW ENGINE INNODB STATUS': show-engine. or one of the *Note
`InnoDB': innodb-storage-engine. Monitor tables) could cause a
server crash due to invalid access to a shared variable in a
concurrent environment. (Bug#38883
(http://bugs.mysql.com/bug.php?id=38883))

* Output from *Note `mysql --html': mysql. did not encode the `<',
`>', or `&' characters. (Bug#27884
(http://bugs.mysql.com/bug.php?id=27884))

File: manual.info, Node: news-5-0-88, Next: news-5-0-87sp1, Prev: news-5-0-89, Up: news-5-0-x

D.1.5 Changes in MySQL 5.0.88 (04 November 2009)
------------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.87). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Security Fix*: MySQL clients linked against OpenSSL can be
tricked not to check server certificates. (Bug#47320
(http://bugs.mysql.com/bug.php?id=47320), CVE-2009-4028
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-4028))

* *MySQL Cluster*: When a data node had written its GCI marker to
the first page of a megabyte, and that node was later killed
during restart after having processed that page (marker) but
before completing a LCP, the data node could fail with filesystem
errors. (Bug#44952 (http://bugs.mysql.com/bug.php?id=44952)) See
also Bug#42564 (http://bugs.mysql.com/bug.php?id=42564), Bug#44291
(http://bugs.mysql.com/bug.php?id=44291).

* *Replication*: When a session was closed on the master, temporary
tables belonging to that session were logged with the wrong
database names when either of the following conditions was true:

1. The length of the name of the database to which the temporary
table belonged was greater than the length of the current
database name.

2. The current database was not set.

(Bug#48216 (http://bugs.mysql.com/bug.php?id=48216)) See also
Bug#46861 (http://bugs.mysql.com/bug.php?id=46861), Bug#48297
(http://bugs.mysql.com/bug.php?id=48297).

* A query containing a view using temporary tables and multiple
tables in the `FROM' clause and `PROCEDURE ANALYSE()' caused a
server crash.

As a result of this bug fix, `PROCEDURE ANALYSE()' is legal only
in a top-level `SELECT'. (Bug#48293
(http://bugs.mysql.com/bug.php?id=48293)) See also Bug#46184
(http://bugs.mysql.com/bug.php?id=46184).

* Error handling was missing for *Note `SELECT': select. statements
containing subqueries in the `WHERE' clause and that assigned a
*Note `SELECT': select. result to a user variable. The server
could crash as a result. (Bug#48291
(http://bugs.mysql.com/bug.php?id=48291))

* An assertion could fail if the optimizer used a `SPATIAL' index.
(Bug#48258 (http://bugs.mysql.com/bug.php?id=48258), Bug#47019
(http://bugs.mysql.com/bug.php?id=47019))

* A combination of `GROUP BY WITH ROLLUP', `DISTINCT' and the
`const' join type in a query caused a server crash when the
optimizer chose to employ a temporary table to resolve `DISTINCT'.
(Bug#48131 (http://bugs.mysql.com/bug.php?id=48131))

* `mysys/mf_keycache.c' requires threading, but no test was made for
thread support. (Bug#47923
(http://bugs.mysql.com/bug.php?id=47923))

* If the first argument to `GeomFromWKB()' function was a geometry
value, the function just returned its value. However, it failed to
preserve the argument's `null_value' flag, which caused an
unexpected `NULL' value to be returned to the caller, resulting in
a server crash. (Bug#47780
(http://bugs.mysql.com/bug.php?id=47780))

* The GPL and commercial license headers had different sizes, so
that error log, backtrace, core dump, and cluster trace file line
numbers could be off by one if they were not checked against the
version of the source used for the build. (For example, checking a
GPL build backtrace against commercial sources.) (Bug#46216
(http://bugs.mysql.com/bug.php?id=46216))

* During the build of the Red Hat IA64 MySQL server RPM, the system
library link order was incorrect. This made the resulting Red Hat
IA64 RPM depend on "libc.so.6.1(GLIBC_PRIVATE)(64bit)", thus
preventing installation of the package. (Bug#45706
(http://bugs.mysql.com/bug.php?id=45706))

* Failure to treat *Note `BIT': numeric-types. values as unsigned
could lead to unpredictable results. (Bug#42803
(http://bugs.mysql.com/bug.php?id=42803))

* Some queries with nested outer joins could lead to crashes or
incorrect results because an internal data structure was handled
improperly. (Bug#42116 (http://bugs.mysql.com/bug.php?id=42116))

* In a replication scenario with `innodb_locks_unsafe_for_binlog'
enabled on the slave, where rows were changed only on the slave
(not through replication), in some rare cases, many messages of
the following form were written to the slave error log: `InnoDB:
Error: unlock row could not find a 4 mode lock on the record'.
(Bug#41756 (http://bugs.mysql.com/bug.php?id=41756))

* A stub of the previously removed `mysql_odbc_escape_string()'
function was restored to fix a ABI breakage. The function was
intended to be private and used only by Connector/ODBC, but,
unfortunately, it was exported as part of the ABI. Nonetheless,
only a stub is restored as the original function is inherently
broken and shouldn't be used. (Bug#41728
(http://bugs.mysql.com/bug.php?id=41728)) See also Bug#29592
(http://bugs.mysql.com/bug.php?id=29592).

* After renaming a user, granting that user privileges could result
in the user having additional privileges other than those granted.
(Bug#41597 (http://bugs.mysql.com/bug.php?id=41597))

* In some cases, the server did not recognize lettercase differences
between *Note `GRANT': grant. attributes such as table name or
user name. For example, a user was able to perform operations on a
table with privileges of another user with the same user name but
in a different lettercase.

In consequence of this bug fix, the collation for the
`Routine_name' column of the `mysql.proc' table is changed from
`utf8_bin' to `utf8_general_ci'. (Bug#41049
(http://bugs.mysql.com/bug.php?id=41049)) See also Bug#48872
(http://bugs.mysql.com/bug.php?id=48872).

File: manual.info, Node: news-5-0-87sp1, Next: news-5-0-87, Prev: news-5-0-88, Up: news-5-0-x

D.1.6 Release Notes for MySQL Enterprise 5.0.87sp1 [QSP] (03 February 2010)
---------------------------------------------------------------------------

This is a _Service Pack_ release of the MySQL Enterprise Server 5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.87).

If you would like to receive more fine-grained and personalized _update
alerts_ about fixes that are relevant to the version and features you
use, please consider subscribing to _MySQL Enterprise_ (a commercial
MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Replication*: When a session was closed on the master, temporary
tables belonging to that session were logged with the wrong
database names when either of the following conditions was true:

1. The length of the name of the database to which the temporary
table belonged was greater than the length of the current
database name.

2. The current database was not set.

(Bug#48216 (http://bugs.mysql.com/bug.php?id=48216)) See also
Bug#46861 (http://bugs.mysql.com/bug.php?id=46861), Bug#48297
(http://bugs.mysql.com/bug.php?id=48297).

* Building MySQL on Fedora Core 12 64-bit failed, due to errors in
*Note `comp_err': comp-err. (Bug#48864
(http://bugs.mysql.com/bug.php?id=48864))

* Re-execution of a prepared statement could cause a server crash.
(Bug#48508 (http://bugs.mysql.com/bug.php?id=48508))

* A bad typecast could cause query execution to allocate large
amounts of memory. (Bug#48458
(http://bugs.mysql.com/bug.php?id=48458))

* A query containing a view using temporary tables and multiple
tables in the `FROM' clause and `PROCEDURE ANALYSE()' caused a
server crash.

* An assertion could fail if the optimizer used a `SPATIAL' index.
(Bug#48258 (http://bugs.mysql.com/bug.php?id=48258), Bug#47019
(http://bugs.mysql.com/bug.php?id=47019))

File: manual.info, Node: news-5-0-87, Next: news-5-0-86, Prev: news-5-0-87sp1, Up: news-5-0-x

D.1.7 Changes in MySQL 5.0.87 (15 October 2009)
-----------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.86). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Incompatible Change*: In binary installations of MySQL, the
supplied `binary-configure' script would start and configure
MySQL, even when command help was requested with the `--help'
command-line option. The `--help', if provided, will no longer
start and install the server. (Bug#30954
(http://bugs.mysql.com/bug.php?id=30954))

* *Replication*: *Note `BEGIN': commit. statements were not
included in the output of *Note `mysqlbinlog': mysqlbinlog.
(Bug#46998 (http://bugs.mysql.com/bug.php?id=46998))

* *Replication*: Database-level character sets were not always
honored by the replication SQL thread. This could cause data
inserted on the master using *Note `LOAD DATA': load-data. to be
replicated using the wrong character set. (Bug#45516
(http://bugs.mysql.com/bug.php?id=45516))

* *API*: The fix for Bug#24507
(http://bugs.mysql.com/bug.php?id=24507) could lead in some cases
to client application failures due to a race condition. Now the
server waits for the `dummy' thread to return before exiting, thus
making sure that only one thread can initialize the POSIX threads
library. (Bug#42850 (http://bugs.mysql.com/bug.php?id=42850))

* On Mac OS X or Windows, sending a `SIGHUP' signal to the server or
an asynchronous flush (triggered by `flush_time') caused the server
to crash. (Bug#47525 (http://bugs.mysql.com/bug.php?id=47525))

* Solaris binary packages now are compiled with `-g0' rather than
`-g'. (Bug#47137 (http://bugs.mysql.com/bug.php?id=47137))

* *Note `EXPLAIN': explain. caused a server crash for certain valid
queries. (Bug#47106 (http://bugs.mysql.com/bug.php?id=47106))

* When creating a new instance on Windows using *Note `mysqld-nt':
mysqld. and the `--install' parameter, the value of the service
would be set incorrectly, resulting in a failure to start the
configured service. (Bug#46917
(http://bugs.mysql.com/bug.php?id=46917))

* `CONCAT_WS()' could return incorrect results due to an argument
buffer also being used as a result buffer. (Bug#46815
(http://bugs.mysql.com/bug.php?id=46815))

* The server crashed when re-using outer column references in
correlated subqueries when the enclosing query used a temp table.
(Bug#46791 (http://bugs.mysql.com/bug.php?id=46791))

* The server ignored the setting of `sync_frm' for *Note `CREATE
TABLE ... LIKE': create-table. (Bug#46591
(http://bugs.mysql.com/bug.php?id=46591))

* An attempt to create a table with the same name as an existing
view could cause a server crash. (Bug#46384
(http://bugs.mysql.com/bug.php?id=46384))

* A memory leak occurred when *Note `EXPLAIN': explain. encountered
a malformed query. (Bug#45989
(http://bugs.mysql.com/bug.php?id=45989))

* When re-installing MySQL on Windows on a server that has a data
directory from a previous MySQL installation, the installer would
fail to identify the existence of the installation and the
password configured for the `root' user. (Bug#45200
(http://bugs.mysql.com/bug.php?id=45200))

* Client flags were incorrectly initialized for the embedded server,
causing several tests in the `jp' test suite to fail. (Bug#45159
(http://bugs.mysql.com/bug.php?id=45159))

* A test for stack growth failed on some platforms, leading to
server crashes. (Bug#42213
(http://bugs.mysql.com/bug.php?id=42213))

* The server used the wrong lock type (always `TL_READ' instead of
`TL_READ_NO_INSERT' when appropriate) for tables used in
subqueries of *Note `UPDATE': update. statements. This led in some
cases to replication failure because statements were written in
the wrong order to the binary log. (Bug#42108
(http://bugs.mysql.com/bug.php?id=42108))

* Concurrent execution of *Note `FLUSH TABLES': flush. along with
*Note `SHOW FUNCTION STATUS': show-function-status. or *Note
`SHOW PROCEDURE STATUS': show-procedure-status. could cause a
server crash. (Bug#34895 (http://bugs.mysql.com/bug.php?id=34895))

* *Note `myisamchk': myisamchk. performed parameter value casting at
startup that generated unnecessary warning messages. (Bug#33785
(http://bugs.mysql.com/bug.php?id=33785))

* When building MySQL on Windows from source, the
`WITH_BERKELEY_STORAGE_ENGINE' option would fail to configure
`BDB' support correctly. (Bug#27693
(http://bugs.mysql.com/bug.php?id=27693))

* Changing the size of a key buffer that is under heavy use could
cause a server crash. The fix partially removes the limitation
that *Note `LOAD INDEX INTO CACHE': load-index. fails unless all
indexes in a table have the same block size. Now the statement
fails only if `IGNORE LEAVES' is specified. (Bug#17332
(http://bugs.mysql.com/bug.php?id=17332))

File: manual.info, Node: news-5-0-86, Next: news-5-0-85, Prev: news-5-0-87, Up: news-5-0-x

D.1.8 Changes in MySQL 5.0.86 (09 September 2009)
-------------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.85). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Performance*: For `MyISAM' tables with `bulk_insert_buffer_size'
values larger than 256KB, the performance of bulk insert operations
such as multiple-row *Note `INSERT': insert. and *Note `INSERT ...
SELECT': insert. operations has been improved greatly when up to a
hundred rows are inserted at the same time. (Bug#44723
(http://bugs.mysql.com/bug.php?id=44723))

* *Replication*: When using the `--replicate-rewrite-db' option and
the database referenced by this option on the master was the
current database when the connection to the slave was closed, any
temporary tables existing in this database were not properly
dropped. (Bug#46861 (http://bugs.mysql.com/bug.php?id=46861))

* *Replication*: In some cases, a *Note `STOP SLAVE': stop-slave.
statement could cause the replication slave to crash. This issue
was specific to MySQL on Windows or Macintosh platforms.
(Bug#45238 (http://bugs.mysql.com/bug.php?id=45238), Bug#45242
(http://bugs.mysql.com/bug.php?id=45242), Bug#45243
(http://bugs.mysql.com/bug.php?id=45243), Bug#46013
(http://bugs.mysql.com/bug.php?id=46013), Bug#46014
(http://bugs.mysql.com/bug.php?id=46014), Bug#46030
(http://bugs.mysql.com/bug.php?id=46030)) See also Bug#40796
(http://bugs.mysql.com/bug.php?id=40796).

* Stack overflow checking did not account for the size of the
structure stored in the heap. (Bug#46807
(http://bugs.mysql.com/bug.php?id=46807))

* The server could crash for queries with the following elements: 1.
An `impossible where' in the outermost `SELECT'; 2. An aggregate
in the outermost `SELECT'; 3. A correlated subquery with a `WHERE'
clause that includes an outer field reference as a top-level
`WHERE' sargable predicate; (Bug#46749
(http://bugs.mysql.com/bug.php?id=46749))

* *Note `CREATE TABLE ... SELECT': create-table. could cause
assertion failure if a table already existed with the same name
and contained an `AUTO_INCREMENT' column. (Bug#46616
(http://bugs.mysql.com/bug.php?id=46616))

* A query containing a subquery in the `FROM' clause and `PROCEDURE
ANALYSE()' caused a server crash. (Bug#46184
(http://bugs.mysql.com/bug.php?id=46184)) See also Bug#48293
(http://bugs.mysql.com/bug.php?id=48293).

* If `--basedir' was specified, *Note `mysqld_safe': mysqld-safe.
did not use it when attempting to locate *Note
`my_print_defaults': my-print-defaults. (Bug#39326
(http://bugs.mysql.com/bug.php?id=39326))

* A buffer overflow could occur during handling of `IS NULL' ranges.
(Bug#37044 (http://bugs.mysql.com/bug.php?id=37044))

* *Note `mysqladmin --wait ping': mysqladmin. crashed on Windows
systems. (Bug#35132 (http://bugs.mysql.com/bug.php?id=35132))

File: manual.info, Node: news-5-0-85, Next: news-5-0-84sp1, Prev: news-5-0-86, Up: news-5-0-x

D.1.9 Changes in MySQL 5.0.85 (11 August 2009)
----------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.84). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Important Change*: Uninstalling MySQL using the MySQL installer
on Windows would delete the `my.ini' file. The file is no longer
deleted. In addition, when a new installation is conducted, any
existing cofiguration file will be renamed to `myDATETIME.ini.bak'
during configuration. (Bug#36493
(http://bugs.mysql.com/bug.php?id=36493))

* The server printed warnings at startup about adjusting the value
of the `max_join_size' system variable. (These were harmless, but
might be seen by users as significant.) (Bug#46385
(http://bugs.mysql.com/bug.php?id=46385))

* The server crashed if evaluation of `GROUP_CONCAT(... ORDER BY)'
required allocation of a sort buffer but allocation failed.
(Bug#46080 (http://bugs.mysql.com/bug.php?id=46080))

* After an error such as a table-full condition, *Note `INSERT
IGNORE': insert. could cause an assertion failure for debug
builds. (Bug#46075 (http://bugs.mysql.com/bug.php?id=46075))

* An optimization that moved an item from a subquery to an outer
query could cause a server crash. (Bug#46051
(http://bugs.mysql.com/bug.php?id=46051))

* Several Valgrind warnings were corrected. (Bug#46003
(http://bugs.mysql.com/bug.php?id=46003), Bug#46034
(http://bugs.mysql.com/bug.php?id=46034), Bug#46042
(http://bugs.mysql.com/bug.php?id=46042))

* For problems reading SSL files during SSL initialization, the
server wrote error messages to `stderr' rather than to the error
log. (Bug#45770 (http://bugs.mysql.com/bug.php?id=45770))

* The vendor name change from MySQL AB to Sun Microsystems, Inc. in
RPM packages was not handled gracefully when upgrading MySQL using
an RPM package. (Bug#45534
(http://bugs.mysql.com/bug.php?id=45534))

* A Windows Installation using the GUI installer would fail with:

MySQL Server 5.1 Setup Wizard ended prematurely

The wizard was interrupted before MySQL Server 5.1. could be completely installed.

Your system has not been modified. To complete installation at another time, please run
setup again.

Click Finish to exit the wizard

This was due to an step in the MSI installer that could fail to
execute correctly on some environments. (Bug#45418
(http://bugs.mysql.com/bug.php?id=45418))

* Compiler warnings on Windows were fixed. (Bug#45287
(http://bugs.mysql.com/bug.php?id=45287))

* Invalid memory reads could occur using the compressed
client/server protocol. (Bug#45031
(http://bugs.mysql.com/bug.php?id=45031))

* Invalid input could cause invalid memory reads by the parser.
(Bug#45010 (http://bugs.mysql.com/bug.php?id=45010))

* Creating a new instance after previously removing an instance
would fail to complete the installation properly because the
security settings could not be applied correctly. (Bug#44428
(http://bugs.mysql.com/bug.php?id=44428))

* The server did not always check the return value of calls to the
`hash_init()' function. (Bug#43572
(http://bugs.mysql.com/bug.php?id=43572))

* A test for stack growth failed on some platforms, leading to
server crashes. (Bug#42213
(http://bugs.mysql.com/bug.php?id=42213))

* *Note `SHOW PROCESSLIST': show-processlist. could access freed
memory of a stored procedure run in a concurrent session.
(Bug#38816 (http://bugs.mysql.com/bug.php?id=38816))

* During installation on Windows, the MySQL Instance Configuration
Wizard window could be opened at a size too small to be usable.
(Bug#38723 (http://bugs.mysql.com/bug.php?id=38723))

* `make_binary_distribution' did not always generate correct
distribution names. (Bug#37808
(http://bugs.mysql.com/bug.php?id=37808))

* The server crashed when executing a prepared statement containing
a duplicated `MATCH()' function call in the select list and `ORDER
BY' clause; for example, `SELECT MATCH(a) AGAINST('test') FROM t1
ORDER BY MATCH(a) AGAINST('test')'. (Bug#37740
(http://bugs.mysql.com/bug.php?id=37740))

* When performing an installation on Windows using the GUI
installer, the installer would fail to wait long enough during
installation for the MySQL service to be installed, which would
cause the installation to fail and may cause security settings,
such as the `root' password to not be applied correctly.
(Bug#30525 (http://bugs.mysql.com/bug.php?id=30525))

* If `InnoDB' reached its limit on the number of concurrent
transactions (1023), it wrote a descriptive message to the error
log but returned a misleading error message to the client, or an
assertion failure occurred. (Bug#18828
(http://bugs.mysql.com/bug.php?id=18828)) See also Bug#46672
(http://bugs.mysql.com/bug.php?id=46672).

* Installation of MySQL on Windows would fail to set the correct
location for the character set files, which could lead to *Note
`mysqld': mysqld. and *Note `mysql': mysql. failing to initialize
properly. (Bug#17270 (http://bugs.mysql.com/bug.php?id=17270))

File: manual.info, Node: news-5-0-84sp1, Next: news-5-0-84, Prev: news-5-0-85, Up: news-5-0-x

D.1.10 Release Notes for MySQL Enterprise 5.0.84sp1 [QSP] (30 September 2009)
-----------------------------------------------------------------------------

This is a _Service Pack_ release of the MySQL Enterprise Server 5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.84).

Bugs fixed:

* A Windows Installation using the GUI installer would fail with:

MySQL Server 5.1 Setup Wizard ended prematurely

The wizard was interrupted before MySQL Server 5.1. could be completely installed.

Your system has not been modified. To complete installation at another time, please run
setup again.

Click Finish to exit the wizard

This was due to an step in the MSI installer that could fail to
execute correctly on some environments. (Bug#45418
(http://bugs.mysql.com/bug.php?id=45418))

File: manual.info, Node: news-5-0-84, Next: news-5-0-83, Prev: news-5-0-84sp1, Up: news-5-0-x

D.1.11 Changes in MySQL 5.0.84 (07 July 2009)
---------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.83). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Performance*: The `InnoDB' adaptive hash latch is released (if
held) for several potentially long-running operations. This
improves throughput for other queries if the current query is
removing a temporary table, changing a temporary table from memory
to disk, using *Note `CREATE TABLE ... SELECT': create-table, or
performing a `MyISAM' repair on a table used within a transaction.
(Bug#32149 (http://bugs.mysql.com/bug.php?id=32149))

* *Security Fix*: A suitable database identifier supplied to the
`COM_CREATE_DB' or `COM_DROP_DB' command could cause a
segmentation fault, and thereby a denial of service. (Bug#45790
(http://bugs.mysql.com/bug.php?id=45790), CVE-2009-2446
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2446))

* *Security Fix*: The server crashed if an account with the `CREATE
ROUTINE' privilege but not the `EXECUTE' privilege attempted to
create a stored procedure. (Bug#44798
(http://bugs.mysql.com/bug.php?id=44798))

* *Important Change*: *Replication*: *Note `BEGIN': commit, *Note
`COMMIT': commit, and *Note `ROLLBACK': commit. statements are no
longer affected by `--replicate-do-db' or `--replicate-ignore-db'
rules. (Bug#43263 (http://bugs.mysql.com/bug.php?id=43263))

* *Replication*: When reading a binary log that was in use by a
master or that had not been properly closed (possibly due to a
crash), the following message was printed: `Warning: this binlog
was not closed properly. Most probably mysqld crashed writing it'.
This message did not take into account the possibility that the
file was merely in use by the master, which caused some users
concern who were not aware that this could happen.

To make this clear, the original message has been replaced with
`Warning: this binlog is either is use or was not closed properly'.
(Bug#34687 (http://bugs.mysql.com/bug.php?id=34687))

* The server crashed for attempts to use *Note `REPLACE': replace. or
*Note `INSERT ... ON DUPLICATE KEY UPDATE': insert. with a view
defined using a join. (Bug#45806
(http://bugs.mysql.com/bug.php?id=45806))

* The combination of `MIN()' or `MAX()' in the select list with
`WHERE' and `GROUP BY' clauses could lead to incorrect results.
(Bug#45386 (http://bugs.mysql.com/bug.php?id=45386))

* Compiler warnings on Mac OS X were fixed. (Bug#45286
(http://bugs.mysql.com/bug.php?id=45286))

* The *Note `mysql': mysql. client could misinterpret some character
sequences as commands under some circumstances. (Bug#45236
(http://bugs.mysql.com/bug.php?id=45236))

* Use of `ROUND()' on a *Note `LONGTEXT': blob. or *Note `LONGBLOB':
blob. column of a derived table could cause a server crash.
(Bug#45152 (http://bugs.mysql.com/bug.php?id=45152))

* Index Merge followed by a filesort could result in a server crash
if `sort_buffer_size' was not large enough for all sort keys.
(Bug#44810 (http://bugs.mysql.com/bug.php?id=44810)) See also
Bug#40974 (http://bugs.mysql.com/bug.php?id=40974).

* The `PASSWORD()' and `OLD_PASSWORD()' functions could read memory
outside of an internal buffer when used with *Note `BLOB': blob.
arguments. (Bug#44767 (http://bugs.mysql.com/bug.php?id=44767))

* Some Perl scripts in AIX packages contained an incorrect path to
the `perl' executable. (Bug#44643
(http://bugs.mysql.com/bug.php?id=44643))

* A workaround for a Sun Studio bug was instituted. (Bug#41710
(http://bugs.mysql.com/bug.php?id=41710))

* Shared-memory connections did not work in Vista if *Note `mysqld':
mysqld. was started from the command line. (Bug#41190
(http://bugs.mysql.com/bug.php?id=41190))

* Some *Note `UPDATE': update. statements that affected no rows
returned a rows-affected count of one. (Bug#40565
(http://bugs.mysql.com/bug.php?id=40565))

* Valgrind warnings that occurred for *Note `SHOW TABLE STATUS':
show-table-status. with `InnoDB' tables were silenced. (Bug#38479
(http://bugs.mysql.com/bug.php?id=38479))

* In the *Note `mysql': mysql. client, using a default character set
of `binary' caused internal commands such as `DELIMITER' to become
case sensitive. (Bug#37268
(http://bugs.mysql.com/bug.php?id=37268))

* A Valgrind error during subquery execution was corrected.
(Bug#36995 (http://bugs.mysql.com/bug.php?id=36995))

* When invoked to start multiple server instances, *Note
`mysqld_multi': mysqld-multi. sometimes would fail to start them
all due to not changing location into the base directory for each
instance. (Bug#36654 (http://bugs.mysql.com/bug.php?id=36654))

* On Windows, the `_PC' macro in `my_global.h' was causing problems
for modern compilers. It has been removed because it is no longer
used. (Bug#34309 (http://bugs.mysql.com/bug.php?id=34309))

* Setting the session value of the `max_allowed_packet' or
`net_buffer_length' system variable was permitted but had no
effect. The session value of these variables is now read only.
(Bug#32223 (http://bugs.mysql.com/bug.php?id=32223)) See also
Bug#22891 (http://bugs.mysql.com/bug.php?id=22891).

File: manual.info, Node: news-5-0-83, Next: news-5-0-82sp1, Prev: news-5-0-84, Up: news-5-0-x

D.1.12 Changes in MySQL 5.0.83 (29 May 2009)
--------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.82). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Functionality added or changed:

Bugs fixed:

* *Replication*: When stopping and restarting the slave while it was
replicating temporary tables, the slave server could crash or
raise an assertion failure. This was due to the fact that, although
temporary tables were saved between slave thread restarts, the
reference to the thread being used (`table->in_use') was not being
properly updated when restarting, continuing to reference the old
thread instead of the new one. This issue affected statement-based
replication only. (Bug#41725
(http://bugs.mysql.com/bug.php?id=41725))

* `UNCOMPRESSED_LENGTH()' returned a garbage result when passed a
string shorter than 5 bytes. Now `UNCOMPRESSED_LENGTH()' returns
`NULL' and generates a warning. (Bug#44796
(http://bugs.mysql.com/bug.php?id=44796))

* Several Valgrind warnings were silenced. (Bug#44774
(http://bugs.mysql.com/bug.php?id=44774), Bug#44792
(http://bugs.mysql.com/bug.php?id=44792))

* Incorrect time was reported at the end of *Note `mysqldump':
mysqldump. output. (Bug#44424
(http://bugs.mysql.com/bug.php?id=44424))

* *Note `EXPLAIN EXTENDED': explain. could crash for *Note `UNION':
union. queries in which the last *Note `SELECT': select. was not
parenthesized and included an `ORDER BY' clause. (Bug#43612
(http://bugs.mysql.com/bug.php?id=43612))

* *Note `SELECT ... INTO @var': select. could produce values
different from *Note `SELECT ...': select. without the `INTO'
clause. (Bug#42009 (http://bugs.mysql.com/bug.php?id=42009))

* Using `--hexdump' together with `--read-from-remote-server' caused
*Note `mysqlbinlog': mysqlbinlog. to crash. (Bug#41943
(http://bugs.mysql.com/bug.php?id=41943))

* A crash occurred due to a race condition between the merge table
and `table_cache' evictions.

00000001403C452F mysqld.exe!memcpy()[memcpy.asm:151]
00000001402A275F mysqld.exe!ha_myisammrg::info()[ha_myisammrg.cc:854]
00000001402A2471 mysqld.exe!ha_myisammrg::attach_children()[ha_myisammrg.cc:488]
00000001402A2788 mysqld.exe!ha_myisammrg::extra()[ha_myisammrg.cc:863]
000000014015FC5D mysqld.exe!attach_merge_children()[sql_base.cc:4135]
000000014016A4C1 mysqld.exe!open_tables()[sql_base.cc:4697]
000000014016A898 mysqld.exe!open_and_lock_tables_derived()[sql_base.cc:4956]
000000014018BB54 mysqld.exe!mysql_insert()[sql_insert.cc:613]
000000014019EDD3 mysqld.exe!mysql_execute_command()[sql_parse.cc:3066]
00000001401A2F06 mysqld.exe!mysql_parse()[sql_parse.cc:5791]
00000001401A3C1A mysqld.exe!dispatch_command()[sql_parse.cc:1202]
00000001401A4CD7 mysqld.exe!do_command()[sql_parse.cc:857]
0000000140246327 mysqld.exe!handle_one_connection()[sql_connect.cc:1115]
00000001402B82C5 mysqld.exe!pthread_start()[my_winthread.c:85]
00000001403CAC37 mysqld.exe!_callthreadstart()[thread.c:295]
00000001403CAD05 mysqld.exe!_threadstart()[thread.c:275]
0000000077D6B69A kernel32.dll!BaseThreadStart()
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...

(Bug#41212 (http://bugs.mysql.com/bug.php?id=41212))

* For some queries, an equality propagation problem could cause `a =
b' and `b = a' to be handled differently. (Bug#40925
(http://bugs.mysql.com/bug.php?id=40925))

* For views created with a column list clause, column aliases were
not substituted when selecting through the view using a `HAVING'
clause. (Bug#40825 (http://bugs.mysql.com/bug.php?id=40825))

* A multiple-table *Note `DELETE': delete. involving a table
self-join could cause a server crash. (Bug#39918
(http://bugs.mysql.com/bug.php?id=39918))

* Creating an `InnoDB' table with a comment containing a `'#''
character caused foreign key constraints to be omitted.
(Bug#39793 (http://bugs.mysql.com/bug.php?id=39793))

* The *Note `mysql': mysql. option `--ignore-spaces' was
nonfunctional. (Bug#39101
(http://bugs.mysql.com/bug.php?id=39101))

* If a query was such as to produce the error `1054 Unknown column
'...' in 'field list'', using *Note `EXPLAIN EXTENDED': explain.
with the query could cause a server crash. (Bug#37362
(http://bugs.mysql.com/bug.php?id=37362))

File: manual.info, Node: news-5-0-82sp1, Next: news-5-0-82, Prev: news-5-0-83, Up: news-5-0-x

D.1.13 Release Notes for MySQL Enterprise 5.0.82sp1 [QSP] (21 July 2009)
------------------------------------------------------------------------

This is a _Service Pack_ release of the MySQL Enterprise Server 5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.82).

Bugs fixed:

* Use of `ROUND()' on a *Note `LONGTEXT': blob. or *Note `LONGBLOB':
blob. column of a derived table could cause a server crash.
(Bug#45152 (http://bugs.mysql.com/bug.php?id=45152))

File: manual.info, Node: news-5-0-82, Next: news-5-0-81, Prev: news-5-0-82sp1, Up: news-5-0-x

D.1.14 Changes in MySQL 5.0.82 (20 May 2009)
--------------------------------------------

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server and MySQL Community Server
release (5.0.80). If you would like to receive more fine-grained and
personalized _update alerts_ about fixes that are relevant to the
version and features you use, please consider subscribing to _MySQL
Enterprise_ (a commercial MySQL offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Performance*: *Note `InnoDB': innodb-storage-engine. uses random
numbers to generate dives into indexes for calculating index
cardinality. However, under certain conditions, the algorithm did
not generate random numbers, so *Note `ANALYZE TABLE':
analyze-table. did not update cardinality estimates properly. A
new algorithm has been introduced with better randomization
properties, together with a system variable,
`innodb_use_legacy_cardinality_algorithm', that controls which
algorithm to use. The default value of the variable is 1 (`ON'),
to use the original algorithm for compatibility with existing
applications. The variable can be set to 0 (`OFF') to use the new
algorithm with improved randomness. (Bug#43660
(http://bugs.mysql.com/bug.php?id=43660))

* *Replication*: Restarting the replication slave--either by using
*Note `STOP SLAVE': stop-slave. plus *Note `START SLAVE':
start-slave, or by restarting the slave *Note `mysqld': mysqld.
process--could sometimes cause the slave to crash when using a
debug version of the server. (Bug#38694
(http://bugs.mysql.com/bug.php?id=38694))

* *Replication*: Killing the thread executing a DDL statement, after
it had finished its execution but before it had written the binlog
event, caused the error code in the binlog event to be set
(incorrectly) to ER_SERVER_SHUTDOWN or ER_QUERY_INTERRUPTED, which
caused replication to fail. (Bug#37145
(http://bugs.mysql.com/bug.php?id=37145)) See also Bug#27571
(http://bugs.mysql.com/bug.php?id=27571), Bug#22725
(http://bugs.mysql.com/bug.php?id=22725).

* *Replication*: Column aliases used inside subqueries were ignored
in the binary log. (Bug#35515
(http://bugs.mysql.com/bug.php?id=35515))

* *Replication*: The statements *Note `DROP PROCEDURE IF EXISTS':
drop-procedure. and *Note `DROP FUNCTION IF EXISTS':
drop-function. were not written to the binary log if the procedure
or function to be dropped did not exist. (Bug#13684
(http://bugs.mysql.com/bug.php?id=13684)) See also Bug#25705
(http://bugs.mysql.com/bug.php?id=25705).

* Use of *Note `HANDLER': handler. statements with
`INFORMATION_SCHEMA' tables caused a server crash. Now *Note
`HANDLER': handler. is prohibited with such tables. (Bug#44151
(http://bugs.mysql.com/bug.php?id=44151))

* *Note `myisamchk': myisamchk. could display a negative `Max
keyfile length' value. (Bug#43950
(http://bugs.mysql.com/bug.php?id=43950))

* *Note `mysqld_multi': mysqld-multi. incorrectly passed
`--no-defaults' to *Note `mysqld_safe': mysqld-safe. (Bug#43876
(http://bugs.mysql.com/bug.php?id=43876))

* On Windows, a server crash occurred for attempts to insert a
floating-point value into a *Note `CHAR': char. column with a
maximum length less than the converted floating-point value length.
(Bug#43833 (http://bugs.mysql.com/bug.php?id=43833))

* *Note `UNION': union. of floating-point numbers did unnecessary
rounding. (Bug#43432 (http://bugs.mysql.com/bug.php?id=43432))

* Certain statements might open a table and then wait for an
impending global read lock without noticing whether they hold a
table being waiting for by the global read lock, causing a hang.
Affected statements are *Note `SELECT ... FOR UPDATE': select,
*Note `LOCK TABLES ... WRITE': lock-tables, *Note `TRUNCATE
TABLE': truncate-table, and *Note `LOAD DATA INFILE': load-data.
(Bug#43230 (http://bugs.mysql.com/bug.php?id=43230))

* The `InnoDB' `btr_search_drop_page_hash_when_freed()' function had
a race condition. (Bug#42279
(http://bugs.mysql.com/bug.php?id=42279))

* Compressing a table with the *Note `myisampack': myisampack.
utility caused the server to produce Valgrind warnings when it
opened the table. (Bug#41541
(http://bugs.mysql.com/bug.php?id=41541))

* For a `MyISAM' table with `DELAY_KEY_WRITE' enabled, the index
file could be corrupted without the table being marked as crashed
if the server was killed. (Bug#41330
(http://bugs.mysql.com/bug.php?id=41330))

* Multiple-table *Note `UPDATE': update. statements did not properly
activate triggers. (Bug#39953
(http://bugs.mysql.com/bug.php?id=39953))

* The functions listed in *Note gis-mysql-specific-functions::,
previously accepted WKB arguments and returned WKB values. They
now accept WKB or geometry arguments and return geometry values.

The functions listed in *Note gis-wkb-functions::, previously
accepted WKB arguments and returned geometry values. They now
accept WKB or geometry arguments and return geometry values.
(Bug#38990 (http://bugs.mysql.com/bug.php?id=38990))

* An *Note `UPDATE': update. statement that updated a column using
the same `DES_ENCRYPT()' value for each row actually updated
different rows with different values. (Bug#35087
(http://bugs.mysql.com/bug.php?id=35087))

* For shared-memory connections, the read and write methods did not
properly handle asynchronous close events, which could lead to the
client locking up waiting for a server response. For example, a
call to *Note `mysql_real_query()': mysql-real-query. would block
forever on the client side if the executed statement was aborted
on the server side. Thanks to Armin Scho"ffmann for the bug report
and patch. (Bug#33899 (http://bugs.mysql.com/bug.php?id=33899))

* *Note `CHECKSUM TABLE': checksum-table. was not killable with
*Note `KILL QUERY': kill. (Bug#33146
(http://bugs.mysql.com/bug.php?id=33146))

* *Note `myisamchk': myisamchk. and *Note `myisampack': myisampack.
were not being linked with the library that enabled support for
`*' filename pattern expansion. (Bug#29248
(http://bugs.mysql.com/bug.php?id=29248))

* *Note `COMMIT': commit. did not delete savepoints if there were no
changes in the transaction. (Bug#26288
(http://bugs.mysql.com/bug.php?id=26288))

* Several memory allocation functions were not being checked for
out-of-memory return values. (Bug#25058
(http://bugs.mysql.com/bug.php?id=25058))

File: manual.info, Node: news-5-0-81, Next: news-5-0-80, Prev: news-5-0-82, Up: news-5-0-x

D.1.15 Release Notes for MySQL Community Server 5.0.81 (01 May 2009)
--------------------------------------------------------------------

This is a bugfix release for the current MySQL Community Server
production release family. It replaces MySQL 5.0.77.

Functionality added or changed:

* *Security Enhancement*: To enable stricter control over the
location from which user-defined functions can be loaded, the
`plugin_dir' system variable has been backported from MySQL 5.1.
If the value is nonempty, user-defined function object files can
be loaded only from the directory named by this variable. If the
value is empty, the behavior that is used prior to the inclusion of
`plugin_dir' applies: The UDF object files must be located in a
directory that is searched by your system's dynamic linker.

* A new status variable, `Queries', indicates the number of
statements executed by the server. This includes statements
executed within stored programs, unlike the `Questions' variable
which includes only statements sent to the server by clients.
(Bug#41131 (http://bugs.mysql.com/bug.php?id=41131))

* Previously, index hints did not work for `FULLTEXT' searches. Now
they work as follows:

For natural language mode searches, index hints are silently
ignored. For example, `IGNORE INDEX(i)' is ignored with no warning
and the index is still used.

For boolean mode searches, index hints are honored. (Bug#38842
(http://bugs.mysql.com/bug.php?id=38842))

Bugs fixed:

* *Important Change*: *Security Fix*: Additional corrections were
made for the symlink-related privilege problem originally
addressed in MySQL 5.0.60. The original fix did not correctly
handle the data directory path name if it contained symlinked
directories in its path, and the check was made only at
table-creation time, not at table-opening time later. (Bug#32167
(http://bugs.mysql.com/bug.php?id=32167), CVE-2008-2079
(http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2079)) See
also Bug#39277 (http://bugs.mysql.com/bug.php?id=39277).

* *Security Enhancement*: The server consumed excess memory while
parsing statements with hundreds or thousands of nested boolean
conditions (such as `OR (OR ... (OR ... ))'). This could lead to a
server crash or incorrect statement execution, or cause other
client statements to fail due to lack of memory. The latter result
constitutes a denial of service. (Bug#38296
(http://bugs.mysql.com/bug.php?id=38296))

* *Incompatible Change*: There were some problems using `DllMain()'
hook functions on Windows that automatically do global and
per-thread initialization for `libmysqld.dll':

* Per-thread initialization: MySQL internally counts the number
of active threads, which causes a delay in `my_end()' if not
all threads have exited. But there are threads that can be
started either by Windows internally (often in TCP/IP
scenarios) or by users. Those threads do not necessarily use
`libmysql.dll' functionality but still contribute to the
open-thread count. (One symptom is a five-second delay in
times for PHP scripts to finish.)

* Process-initialization: *Note `my_init()': my-init. calls
`WSAStartup' that itself loads DLLs and can lead to a
deadlock in the Windows loader.

To correct these problems, DLL initialization code now is not
invoked from `libmysql.dll' by default. To obtain the previous
behavior (DLL initialization code will be called), set the
`LIBMYSQL_DLLINIT' environment variable to any value. This
variable exists only to prevent breakage of existing Windows-only
applications that do not call *Note `mysql_thread_init()':
mysql-thread-init. and work okay today. Use of `LIBMYSQL_DLLINIT'
is discouraged and is removed in MySQL 6.0. (Bug#37226
(http://bugs.mysql.com/bug.php?id=37226), Bug#33031
(http://bugs.mysql.com/bug.php?id=33031))

* *Incompatible Change*: *Note `SHOW STATUS': show-status. took a
lot of CPU time for calculating the value of the
`Innodb_buffer_pool_pages_latched' status variable. Now this
variable is calculated and included in the output of *Note `SHOW
STATUS': show-status. only if the `UNIV_DEBUG' symbol is defined
at MySQL build time. (Bug#36600
(http://bugs.mysql.com/bug.php?id=36600))

* *Incompatible Change*: In connection with view creation, the
server created `arc' directories inside database directories and
maintained useless copies of `.frm' files there. Creation and
renaming procedures of those copies as well as creation of `arc'
directories has been discontinued.

This change does cause a problem when downgrading to older server
versions which manifests itself under these circumstances:

1. Create a view `v_orig' in MySQL 5.0.72 or higher.

2. Rename the view to `v_new' and then back to `v_orig'.

3. Downgrade to an older 5.0.x server and run *Note
`mysql_upgrade': mysql-upgrade.

4. Try to rename `v_orig' to `v_new' again. This operation fails.

As a workaround to avoid this problem, use either of these
approaches:

* Dump your data using *Note `mysqldump': mysqldump. before
downgrading and reload the dump file after downgrading.

* Instead of renaming a view after the downgrade, drop it and
recreate it.

The downgrade problem introduced by the fix for this bug has been
addressed as Bug#40021 (http://bugs.mysql.com/bug.php?id=40021).
(Bug#17823 (http://bugs.mysql.com/bug.php?id=17823))

* *Replication*: When rotating relay log files, the slave deletes
relay log files and then edits the relay log index file. Formerly,
if the slave shut down unexpectedly between these two events, the
relay log index file could then reference relay logs that no longer
existed. Depending on the circumstances, this could when
restarting the slave cause either a race condition or the failure
of replication. (Bug#38826
(http://bugs.mysql.com/bug.php?id=38826), Bug#39325
(http://bugs.mysql.com/bug.php?id=39325))

* In example option files provided in MySQL distributions, the
`thread_stack' value was increased from 64K to 128K. (Bug#41577
(http://bugs.mysql.com/bug.php?id=41577))

* *Note `SET PASSWORD': set-password. caused a server crash if the
account name was given as `CURRENT_USER()'. (Bug#41456
(http://bugs.mysql.com/bug.php?id=41456))

* The *Note `INFORMATION_SCHEMA.SCHEMA_PRIVILEGES':
schema-privileges-table. table was limited to 7680 rows.
(Bug#41079 (http://bugs.mysql.com/bug.php?id=41079))

* In debug builds, obsolete debug code could be used to crash the
server. (Bug#41041 (http://bugs.mysql.com/bug.php?id=41041))

* *Note `CHECK TABLE ... FOR UPGRADE': check-table. did not check
for incompatible collation changes made in MySQL 5.0.48 (Bug#27562
(http://bugs.mysql.com/bug.php?id=27562), Bug#29461
(http://bugs.mysql.com/bug.php?id=29461), Bug#29499
(http://bugs.mysql.com/bug.php?id=29499)). This also affects
*Note `mysqlcheck': mysqlcheck. and *Note `mysql_upgrade':
mysql-upgrade, which cause that statement to be executed. See
*Note checking-table-incompatibilities::. (Bug#40984
(http://bugs.mysql.com/bug.php?id=40984)) See also Bug#39585
(http://bugs.mysql.com/bug.php?id=39585).

* Some queries that used a `range checked for each record' scan
could return incorrect results. (Bug#40974
(http://bugs.mysql.com/bug.php?id=40974)) See also Bug#44810
(http://bugs.mysql.com/bug.php?id=44810).

* Certain *Note `SELECT': select. queries could fail with a
`Duplicate entry' error. (Bug#40953
(http://bugs.mysql.com/bug.php?id=40953))

* The *Note `FEDERATED': federated-storage-engine. handler had a
memory leak. (Bug#40875 (http://bugs.mysql.com/bug.php?id=40875))

* `IF(..., CAST(LONGTEXT_VAL AS UNSIGNED), SIGNED_VAL)' as an
argument to an aggregate function could cause an assertion failure.
(Bug#40761 (http://bugs.mysql.com/bug.php?id=40761))

* Prepared statements permitted invalid dates to be inserted when
the `ALLOW_INVALID_DATES' SQL mode was not enabled. (Bug#40365
(http://bugs.mysql.com/bug.php?id=40365))

* `mc.exe' is no longer needed to compile MySQL on Windows. This
makes it possible to build MySQL from source using Visual Studio
Express 2008. (Bug#40280 (http://bugs.mysql.com/bug.php?id=40280))

* Support for the `revision' field in `.frm' files has been removed.
This addresses the downgrading problem introduced by the fix for
Bug#17823 (http://bugs.mysql.com/bug.php?id=17823). (Bug#40021
(http://bugs.mysql.com/bug.php?id=40021))

* If the operating system is configured to return leap seconds from
OS time calls or if the MySQL server uses a time zone definition
that has leap seconds, functions such as `NOW()' could return a
value having a time part that ends with `:59:60' or `:59:61'. If
such values are inserted into a table, they would be dumped as is
by *Note `mysqldump': mysqldump. but considered invalid when
reloaded, leading to backup/restore problems.

Now leap second values are returned with a time part that ends
with `:59:59'. This means that a function such as `NOW()' can
return the same value for two or three consecutive seconds during
the leap second. It remains true that literal temporal values
having a time part that ends with `:59:60' or `:59:61' are
considered invalid.

For additional details about leap-second handling, see *Note
time-zone-leap-seconds::. (Bug#39920
(http://bugs.mysql.com/bug.php?id=39920))

* The server could crash during a sort-order optimization of a
dependent subquery. (Bug#39844
(http://bugs.mysql.com/bug.php?id=39844))

* With the `ONLY_FULL_GROUP_BY' SQL mode enabled, the check for
nonaggregated columns in queries with aggregate functions, but
without a `GROUP BY' clause was treating all the parts of the
query as if they were in the select list. This is fixed by
ignoring the nonaggregated columns in the `WHERE' clause.
(Bug#39656 (http://bugs.mysql.com/bug.php?id=39656))

* The server crashed if an integer field in a CSV file did not have
delimiting quotation marks. (Bug#39616
(http://bugs.mysql.com/bug.php?id=39616))

* Creating a table with a comment of 62 characters or longer caused
a server crash. (Bug#39591
(http://bugs.mysql.com/bug.php?id=39591))

* *Note `CHECK TABLE': check-table. failed for *Note `MyISAM':
myisam-storage-engine. `INFORMATION_SCHEMA' tables. (Bug#39541
(http://bugs.mysql.com/bug.php?id=39541))

* `InnoDB' could hang trying to open an adaptive hash index.
(Bug#39483 (http://bugs.mysql.com/bug.php?id=39483))

* For a *Note `TIMESTAMP': datetime. column in an `InnoDB' table,
testing the column with multiple conditions in the `WHERE' clause
caused a server crash. (Bug#39353
(http://bugs.mysql.com/bug.php?id=39353))

* The server returned a column type of *Note `VARBINARY':
binary-varbinary. rather than *Note `DATE': datetime. as the
result from the `COALESCE()', `IFNULL()', `IF()', `GREATEST()', or
`LEAST()' functions or `CASE' expression if the result was
obtained using `filesort' in an anonymous temporary table during
the query execution. (Bug#39283
(http://bugs.mysql.com/bug.php?id=39283))

* References to local variables in stored procedures are replaced
with `NAME_CONST(NAME, VALUE)' when written to the binary log.
However, an `illegal mix of collation' error might occur when
executing the log contents if the value's collation differed from
that of the variable. Now information about the variable collation
is written as well. (Bug#39182
(http://bugs.mysql.com/bug.php?id=39182))

* Some recent releases for Solaris 10 were built on Solaris 10 U5,
which included a new version of `libnsl.so' that does not work on
U4 or earlier. To correct this, Solaris 10 builds now are created
on machines that do not have that upgraded `libnsl.so', so that
they will work on Solaris 10 installations both with and without
the upgraded `libnsl.so'. (Bug#39074
(http://bugs.mysql.com/bug.php?id=39074))

* With binary logging enabled *Note `CREATE VIEW': create-view. was
subject to possible buffer overwrite and a server crash.
(Bug#39040 (http://bugs.mysql.com/bug.php?id=39040))

* Queries of the form `SELECT ... REGEXP BINARY NULL' could lead to
a hung or crashed server. (Bug#39021
(http://bugs.mysql.com/bug.php?id=39021))

* Statements of the form `INSERT ... SELECT .. ON DUPLICATE KEY
UPDATE COL_NAME = DEFAULT' could result in a server crash.
(Bug#39002 (http://bugs.mysql.com/bug.php?id=39002))

* Column names constructed due to wild-card expansion done inside a
stored procedure could point to freed memory if the expansion was
performed after the first call to the stored procedure.
(Bug#38823 (http://bugs.mysql.com/bug.php?id=38823))

* Repeated *Note `CREATE TABLE ... SELECT': create-table.
statements, where the created table contained an `AUTO_INCREMENT'
column, could lead to an assertion failure. (Bug#38821
(http://bugs.mysql.com/bug.php?id=38821))

* If delayed insert failed to upgrade the lock, it did not free the
temporary memory storage used to keep newly constructed *Note
`BLOB': blob. values in memory, resulting in a memory leak.
(Bug#38693 (http://bugs.mysql.com/bug.php?id=38693))

* A server crash resulted from concurrent execution of a
multiple-table *Note `UPDATE': update. that used a `NATURAL' or
`USING' join together with *Note `FLUSH TABLES WITH READ LOCK':
flush. or *Note `ALTER TABLE': alter-table. for the table being
updated. (Bug#38691 (http://bugs.mysql.com/bug.php?id=38691))

* On ActiveState Perl, `mysql-test-run.pl --start-and-exit' started
but did not exit. (Bug#38629
(http://bugs.mysql.com/bug.php?id=38629))

* Server-side cursors were not initialized properly, which could
cause a server crash. (Bug#38486
(http://bugs.mysql.com/bug.php?id=38486))

* Stored procedures involving substrings could crash the server on
certain platforms due to invalid memory reads. (Bug#38469
(http://bugs.mysql.com/bug.php?id=38469))

* A server crash or Valgrind warnings could result when a stored
procedure selected from a view that referenced a function.
(Bug#38291 (http://bugs.mysql.com/bug.php?id=38291))

* Incorrect handling of aggregate functions when loose index scan
was used caused a server crash. (Bug#38195
(http://bugs.mysql.com/bug.php?id=38195))

* Queries containing a subquery with `DISTINCT' and `ORDER BY' could
cause a server crash. (Bug#38191
(http://bugs.mysql.com/bug.php?id=38191))

* Queries with a `HAVING' clause could return a spurious row.
(Bug#38072 (http://bugs.mysql.com/bug.php?id=38072))

* Use of spatial data types in prepared statements could cause
memory leaks or server crashes. (Bug#37956
(http://bugs.mysql.com/bug.php?id=37956), Bug#37671
(http://bugs.mysql.com/bug.php?id=37671))

* The server crashed if an argument to a stored procedure was a
subquery that returned more than one row. (Bug#37949
(http://bugs.mysql.com/bug.php?id=37949))

* When analyzing the possible index use cases, the server was
incorrectly reusing an internal structure, leading to a server
crash. (Bug#37943 (http://bugs.mysql.com/bug.php?id=37943))

* A *Note `SELECT': select. with a `NULL NOT IN' condition
containing a complex subquery from the same table as in the outer
select caused an assertion failure. (Bug#37894
(http://bugs.mysql.com/bug.php?id=37894))

* For `InnoDB' tables, `ORDER BY ... DESC' sometimes returned
results in ascending order. (Bug#37830
(http://bugs.mysql.com/bug.php?id=37830))

* If a table has a `BIT NOT NULL' column `c1' with a length shorter
than 8 bits and some additional `NOT NULL' columns `c2', ..., and a
*Note `SELECT': select. query has a `WHERE' clause of the form
`(c1 = CONSTANT) AND c2 ...', the query could return an unexpected
result set. (Bug#37799 (http://bugs.mysql.com/bug.php?id=37799))

* Nesting of `IF()' inside of `SUM()' could cause an extreme server
slowdown. (Bug#37662 (http://bugs.mysql.com/bug.php?id=37662))

* The `MONTHNAME()' and `DAYNAME()' functions returned a binary
string, so that using `LOWER()' or `UPPER()' had no effect. Now
`MONTHNAME()' and `DAYNAME()' return a value in
`character_set_connection' character set. (Bug#37575
(http://bugs.mysql.com/bug.php?id=37575))

* `TIMEDIFF()' was erroneously treated as always returning a
positive result. Also, `CAST()' of *Note `TIME': time. values to
*Note `DECIMAL': numeric-types. dropped the sign of negative
values. (Bug#37553 (http://bugs.mysql.com/bug.php?id=37553)) See
also Bug#42525 (http://bugs.mysql.com/bug.php?id=42525).

* *Note `mysqlcheck': mysqlcheck. used *Note `SHOW FULL TABLES':
show-tables. to get the list of tables in a database. For some
problems, such as an empty `.frm' file for a table, this would
fail and *Note `mysqlcheck': mysqlcheck. then would neglect to
check other tables in the database. (Bug#37527
(http://bugs.mysql.com/bug.php?id=37527))

* The `<=>' operator could return incorrect results when comparing
`NULL' to *Note `DATE': datetime, *Note `TIME': time, or *Note
`DATETIME': datetime. values. (Bug#37526
(http://bugs.mysql.com/bug.php?id=37526))

* Updating a view with a subquery in the `CHECK' option could cause
an assertion failure. (Bug#37460
(http://bugs.mysql.com/bug.php?id=37460))

* Statements that displayed the value of system variables (for
example, *Note `SHOW VARIABLES': show-variables.) expect variable
values to be encoded in `character_set_system'. However, variables
set from the command line such as `basedir' or `datadir' were
encoded using `character_set_filesystem' and not converted
correctly. (Bug#37339 (http://bugs.mysql.com/bug.php?id=37339))

* For a `MyISAM' table with `CHECKSUM = 1' and `ROW_FORMAT =
DYNAMIC' table options, a data consistency check (maximum record
length) could fail and cause the table to be marked as corrupted.
(Bug#37310 (http://bugs.mysql.com/bug.php?id=37310))

* The `max_length' result set metadata value was calculated
incorrectly under some circumstances. (Bug#37301
(http://bugs.mysql.com/bug.php?id=37301))

* *Note `CREATE INDEX': create-index. could crash with `InnoDB'
plugin 1.0.1. (Bug#37284 (http://bugs.mysql.com/bug.php?id=37284))

* Certain boolean-mode `FULLTEXT' searches that used the truncation
operator did not return matching records and calculated relevance
incorrectly. (Bug#37245 (http://bugs.mysql.com/bug.php?id=37245))

* The `NO_BACKSLASH_ESCAPES' SQL mode was ignored for *Note `LOAD
DATA INFILE': load-data. and `SELECT INTO ... OUTFILE'. The
setting is taken into account now. (Bug#37114
(http://bugs.mysql.com/bug.php?id=37114))

* On a 32-bit server built without big tables support, the offset
argument in a `LIMIT' clause might be truncated due to a 64-bit to
32-bit cast. (Bug#37075 (http://bugs.mysql.com/bug.php?id=37075))

* If the server failed to expire binary log files at startup, it
could crash. (Bug#37027 (http://bugs.mysql.com/bug.php?id=37027))

* The code for the `ut_usectime()' function in `InnoDB' did not
handle errors from the `gettimeofday()' system call. Now it retries
`gettimeofday()' several times and updates the value of the
`Innodb_row_lock_time_max' status variable only if `ut_usectime()'
was successful. (Bug#36819
(http://bugs.mysql.com/bug.php?id=36819))

* Use of `CONVERT()' with `GROUP BY' to convert numeric values to
*Note `CHAR': char. could return truncated results. (Bug#36772
(http://bugs.mysql.com/bug.php?id=36772))

* A query which had an `ORDER BY DESC' clause that is satisfied with
a reverse range scan could cause a server crash for some specific
CPU/compiler combinations. (Bug#36639
(http://bugs.mysql.com/bug.php?id=36639))

* Dumping information about locks in use by sending a `SIGHUP'
signal to the server or by invoking the *Note `mysqladmin debug':
mysqladmin. command could lead to a server crash in debug builds
or to undefined behavior in production builds. (Bug#36579
(http://bugs.mysql.com/bug.php?id=36579))

* The *Note `mysql': mysql. client, when built with Visual Studio
2005, did not display Japanese characters. (Bug#36279
(http://bugs.mysql.com/bug.php?id=36279))

* When the fractional part in a multiplication of *Note `DECIMAL':
numeric-types. values overflowed, the server truncated the first
operand rather than the longest. Now the server truncates so as to
produce more precise multiplications. (Bug#36270
(http://bugs.mysql.com/bug.php?id=36270))

* A read past the end of the string could occur while parsing the
value of the `--innodb-data-file-path' option. (Bug#36149
(http://bugs.mysql.com/bug.php?id=36149))

* Host name values in SQL statements were not being checked for
`'@'', which is illegal according to RFC952. (Bug#35924
(http://bugs.mysql.com/bug.php?id=35924))

* The `UUID()' function returned UUIDs with the wrong time; this was
because the offset for the time part in UUIDs was miscalculated.
(Bug#35848 (http://bugs.mysql.com/bug.php?id=35848))

* *Note `SHOW CREATE TABLE': show-create-table. did not display a
printable value for the default value of *Note `BIT':
numeric-types. columns. (Bug#35796
(http://bugs.mysql.com/bug.php?id=35796))

* *Note `mysql_install_db': mysql-install-db. failed on machines
that had the host name set to `localhost'. (Bug#35754
(http://bugs.mysql.com/bug.php?id=35754))

* Dynamic plugins failed to load on i5/OS. (Bug#35743
(http://bugs.mysql.com/bug.php?id=35743))

* Freeing of an internal parser stack during parsing of complex
stored programs caused a server crash. (Bug#35577
(http://bugs.mysql.com/bug.php?id=35577), Bug#37269
(http://bugs.mysql.com/bug.php?id=37269), Bug#37228
(http://bugs.mysql.com/bug.php?id=37228))

* The `max_length' metadata value was calculated incorrectly for the
`FORMAT()' function, which could cause incorrect result set
metadata to be sent to clients. (Bug#35558
(http://bugs.mysql.com/bug.php?id=35558))

* Index scans performed with the `sort_union()' access method
returned wrong results, caused memory to be leaked, and caused
temporary files to be deleted when the limit set by
`sort_buffer_size' was reached. (Bug#35477
(http://bugs.mysql.com/bug.php?id=35477), Bug#35478
(http://bugs.mysql.com/bug.php?id=35478))

* If the server crashed with an `InnoDB' error due to unavailability
of undo slots, errors could persist during rollback when the
server was restarted: There are two `UNDO' slot caches (for *Note
`INSERT': insert. and *Note `UPDATE': update.). If all slots end
up in one of the slot caches, a request for a slot from the other
slot cache would fail. This can happen if the request is for an
*Note `UPDATE': update. slot and all slots are in the *Note
`INSERT': insert. slot cache, or vice versa. (Bug#35352
(http://bugs.mysql.com/bug.php?id=35352))

* For `InnoDB' tables, `ALTER TABLE DROP' failed if the name of the
column to be dropped began with `foreign'. (Bug#35220
(http://bugs.mysql.com/bug.php?id=35220))

* *Note `perror': perror. on Windows did not know about Win32 system
error codes. (Bug#34825 (http://bugs.mysql.com/bug.php?id=34825))

* *Note `EXPLAIN EXTENDED': explain. evaluation of aggregate
functions that required a temporary table caused a server crash.
(Bug#34773 (http://bugs.mysql.com/bug.php?id=34773))

* Queries of the form `SELECT ... WHERE STRING = ANY(...)' failed
when the server used a single-byte character set and the client
used a multi-byte character set. (Bug#34760
(http://bugs.mysql.com/bug.php?id=34760)) See also Bug#20835
(http://bugs.mysql.com/bug.php?id=20835).

* Using *Note `OPTIMIZE TABLE': optimize-table. as the first
statement on an `InnoDB' table with an `AUTO_INCREMENT' column
could cause a server crash. (Bug#34286
(http://bugs.mysql.com/bug.php?id=34286))

* *Note `mysql_install_db': mysql-install-db. failed if the server
was running with an SQL mode of `TRADITIONAL'. This program now
resets the SQL mode internally to avoid this problem. (Bug#34159
(http://bugs.mysql.com/bug.php?id=34159))

* Changes to build files were made to enable the MySQL distribution
to compile on Microsoft Visual C++ Express 2008. (Bug#33907
(http://bugs.mysql.com/bug.php?id=33907))

* The *Note `mysql': mysql. client incorrectly parsed statements
containing the word `delimiter' in mid-statement.

This fix is different from the one applied for this bug in MySQL
5.0.66. (Bug#33812 (http://bugs.mysql.com/bug.php?id=33812)) See
also Bug#38158 (http://bugs.mysql.com/bug.php?id=38158).

* For a stored procedure containing a `SELECT * ... RIGHT JOIN'
query, execution failed for the second call. (Bug#33811
(http://bugs.mysql.com/bug.php?id=33811))

* Previously, use of index hints with views (which do not have
indexes) produced the error `ERROR 1221 (HY000): Incorrect usage
of USE/IGNORE INDEX and VIEW'. Now this produces `ERROR 1176
(HY000): Key '...' doesn't exist in table '...'', the same error
as for base tables without an appropriate index. (Bug#33461
(http://bugs.mysql.com/bug.php?id=33461))

* Cached queries that used 256 or more tables were not properly
cached, so that later query invalidation due to a *Note `TRUNCATE
TABLE': truncate-table. for one of the tables caused the server to
hang. (Bug#33362 (http://bugs.mysql.com/bug.php?id=33362))

* Some division operations produced a result with incorrect
precision. (Bug#31616 (http://bugs.mysql.com/bug.php?id=31616))

* *Note `mysql_upgrade': mysql-upgrade. attempted to use the `/proc'
file system even on systems that do not have it. (Bug#31605
(http://bugs.mysql.com/bug.php?id=31605))

* *Note `mysqldump': mysqldump. could fail to dump views containing
a large number of columns. (Bug#31434
(http://bugs.mysql.com/bug.php?id=31434))

* Queries executed using join buffering of *Note `BIT':
numeric-types. columns could produce incorrect results.
(Bug#31399 (http://bugs.mysql.com/bug.php?id=31399))

* `ALTER TABLE CONVERT TO CHARACTER SET' did not convert *Note
`TINYTEXT': blob. or *Note `MEDIUMTEXT': blob. columns to a longer
text type if necessary when converting the column to a different
character set. (Bug#31291
(http://bugs.mysql.com/bug.php?id=31291))

* For installation on Solaris using `pkgadd' packages, the *Note
`mysql_install_db': mysql-install-db. script was generated in the
`scripts' directory, but the temporary files used during the
process were left there and not deleted. (Bug#31052
(http://bugs.mysql.com/bug.php?id=31052))

* Several MySQL programs could fail if the `HOME' environment
variable had an empty value. (Bug#30394
(http://bugs.mysql.com/bug.php?id=30394))

* On NetWare, *Note `mysql_install_db': mysql-install-db. could
appear to execute normally even if it failed to create the initial
databases. (Bug#30129 (http://bugs.mysql.com/bug.php?id=30129))

* The Serbian translation for the `ER_INCORRECT_GLOBAL_LOCAL_VAR'
error was corrected. (Bug#29738
(http://bugs.mysql.com/bug.php?id=29738))

* XA transaction rollbacks could result in corrupted transaction
states and a server crash. (Bug#28323
(http://bugs.mysql.com/bug.php?id=28323))

* The `BUILD/check-cpu' build script failed if `gcc' had a different
name (such as `gcc.real' on Debian). (Bug#27526
(http://bugs.mysql.com/bug.php?id=27526))

* On Windows, Visual Studio does not take into account some x86
hardware limitations, which led to incorrect results converting
large *Note `DOUBLE': numeric-types. values to unsigned *Note
`BIGINT': numeric-types. values. (Bug#27483
(http://bugs.mysql.com/bug.php?id=27483))

* SSL support was not included in some `generic' RPM packages.
(Bug#26760 (http://bugs.mysql.com/bug.php?id=26760))

* In some cases, the parser interpreted the `;' character as the end
of input and misinterpreted stored program definitions.
(Bug#26030 (http://bugs.mysql.com/bug.php?id=26030))

* The `Questions' status variable is intended as a count of
statements sent by clients to the server, but was also counting
statements executed within stored routines. (Bug#24289
(http://bugs.mysql.com/bug.php?id=24289))

* For access to the *Note `INFORMATION_SCHEMA.VIEWS': views-table.
table, the server did not check the `SHOW VIEW' and *Note
`SELECT': select. privileges, leading to inconsistency between
output from that table and the *Note `SHOW CREATE VIEW':
show-create-view. statement. (Bug#22763
(http://bugs.mysql.com/bug.php?id=22763))

* The *Note `FLUSH PRIVILEGES': flush. statement did not produce an
error when it failed. (Bug#21226
(http://bugs.mysql.com/bug.php?id=21226))

* A race condition between the *Note `mysqld.exe': mysqld. server
and the Windows service manager could lead to inability to stop
the server from the service manager. (Bug#20430
(http://bugs.mysql.com/bug.php?id=20430))

* `mysqld_safe' would sometimes fail to remove the pid file for the
old `mysql' process after a crash. As a result, the server would
fail to start due to a false `A mysqld process already exists...'
error. (Bug#11122 (http://bugs.mysql.com/bug.php?id=11122))

File: manual.info, Node: news-5-0-80, Next: news-5-0-79, Prev: news-5-0-81, Up: news-5-0-x

D.1.16 Release Notes for MySQL Enterprise 5.0.80 [MRU] (01 May 2009)
--------------------------------------------------------------------

This is a _Monthly Rapid Update_ release of the MySQL Enterprise Server
5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.79). If you would
like to receive more fine-grained and personalized _update alerts_
about fixes that are relevant to the version and features you use,
please consider subscribing to _MySQL Enterprise_ (a commercial MySQL
offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Support Ending for AIX 5.2: Per the
http://www.mysql.com/about/legal/lifecycle/ regarding ending support
for OS versions that have reached vendor end of life, we plan to
discontinue building or supporting MySQL binaries for AIX 5.2 as of
April 30, 2009. This release of MySQL 5.0 (5.0.80) is the last MySQL
5.0 release with support for AIX 5.2. For more information, see the
March 24, 2009 note at MySQL Product Support EOL Announcements
(http://dev.mysql.com/support/eol-notice.html).

Functionality added or changed:

* The MD5 algorithm now uses the Xfree implementation. (Bug#42434
(http://bugs.mysql.com/bug.php?id=42434))

Bugs fixed:

* *Replication*: An *Note `INSERT DELAYED': insert. into a *Note
`TIMESTAMP': datetime. column issued concurrently with an insert
on the same column not using `DELAYED', but applied after the
other insert, was logged using the same timestamp as generated by
the other (non-`DELAYED') insert. (Bug#41719
(http://bugs.mysql.com/bug.php?id=41719))

* An attempt by a user who did not have the `SUPER' privilege to
kill a system thread could cause a server crash. (Bug#43748
(http://bugs.mysql.com/bug.php?id=43748))

* Use of `USE INDEX' hints could cause *Note `EXPLAIN EXTENDED':
explain. to crash. (Bug#43354
(http://bugs.mysql.com/bug.php?id=43354))

* *Note `mysql': mysql. crashed if a request for the current
database name returned an empty result, such as after the client
has executed a preceding `SET sql_select_limit=0' statement.
(Bug#43254 (http://bugs.mysql.com/bug.php?id=43254))

* The `strings/CHARSET_INFO.txt' file was not included in source
distributions. (Bug#42937
(http://bugs.mysql.com/bug.php?id=42937))

* *Note `mysqldump': mysqldump. included views that were excluded
with the `--ignore-table' option. (Bug#42635
(http://bugs.mysql.com/bug.php?id=42635))

* Passing an unknown time zone specification to `CONVERT_TZ()'
resulted in a memory leak. (Bug#42502
(http://bugs.mysql.com/bug.php?id=42502))

* The MySQL Instance Configuration Wizard would fail to start
correctly on Windows Vista. (Bug#42386
(http://bugs.mysql.com/bug.php?id=42386))

* With more than two arguments, `LEAST()', `GREATEST()', and `CASE'
could unnecessarily return `Illegal mix of collations' errors.
(Bug#41627 (http://bugs.mysql.com/bug.php?id=41627))

* The *Note `mysql': mysql. client could misinterpret its input if a
line was longer than an internal buffer. (Bug#41486
(http://bugs.mysql.com/bug.php?id=41486))

* In the `help' command output displayed by *Note `mysql': mysql,
the description for the `\c' (`clear') command was misleading.
(Bug#41268 (http://bugs.mysql.com/bug.php?id=41268))

* When running the MySQL Instance Configuration Wizard in
command-line only mode, the service name would be ignored
(effectively creating all instances with the default `MySQL'
service name), irrespective of the name specified on the command
line. However, the wizard would attempt to start the service with
the specified name, and would fail. (Bug#38379
(http://bugs.mysql.com/bug.php?id=38379))

* The use of `NAME_CONST()' can result in a problem for *Note
`CREATE TABLE ... SELECT': create-table. statements when the
source column expressions refer to local variables. Converting
these references to `NAME_CONST()' expressions can result in
column names that are different on the master and slave servers,
or names that are too long to be legal column identifiers. A
workaround is to supply aliases for columns that refer to local
variables.

Now a warning is issued in such cases that indicate possible
problems. (Bug#35383 (http://bugs.mysql.com/bug.php?id=35383))

* *Note `CHECK TABLE': check-table, *Note `REPAIR TABLE':
repair-table, *Note `ANALYZE TABLE': analyze-table, and *Note
`OPTIMIZE TABLE': optimize-table. erroneously reported a table to
be corrupt if the table did not exist or the statement was
terminated with *Note `KILL': kill. (Bug#29458
(http://bugs.mysql.com/bug.php?id=29458))

* The `Time' column for *Note `SHOW PROCESSLIST': show-processlist.
output now can have negative values. Previously, the column was
unsigned and negative values were displayed incorrectly as large
positive values. Negative values can occur if a thread alters the
time into the future with *Note `SET TIMESTAMP = VALUE':
set-option. or the thread is executing on a slave and processing
events from a master that has its clock set ahead of the slave.
(Bug#22047 (http://bugs.mysql.com/bug.php?id=22047))

* Restoring a *Note `mysqldump': mysqldump. dump file containing
`FEDERATED' tables failed because the file contained the data for
the table. Now only the table definition is dumped (because the
data is located elsewhere). (Bug#21360
(http://bugs.mysql.com/bug.php?id=21360))

File: manual.info, Node: news-5-0-79, Next: news-5-0-78, Prev: news-5-0-80, Up: news-5-0-x

D.1.17 Release Notes for MySQL Enterprise 5.0.79 [MRU] (09 March 2009)
----------------------------------------------------------------------

This is a _Monthly Rapid Update_ release of the MySQL Enterprise Server
5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.78). If you would
like to receive more fine-grained and personalized _update alerts_
about fixes that are relevant to the version and features you use,
please consider subscribing to _MySQL Enterprise_ (a commercial MySQL
offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Functionality added or changed:

* *Performance*: The query cache now checks whether a *Note
`SELECT': select. statement begins with `SQL_NO_CACHE' to
determine whether it can skip checking for the query result in the
query cache. This is not supported when `SQL_NO_CACHE' occurs
within a comment. (Bug#37416
(http://bugs.mysql.com/bug.php?id=37416))

* The `libedit' library was upgraded to version 2.11. (Bug#42433
(http://bugs.mysql.com/bug.php?id=42433))

Bugs fixed:

* *Performance*: For an `InnoDB' table, *Note `DROP TABLE':
drop-table. or *Note `ALTER TABLE ... DISCARD TABLESPACE':
alter-table. could take a long time or cause a server crash.
(Bug#39939 (http://bugs.mysql.com/bug.php?id=39939))

* *Replication*: Server IDs greater than 2147483647 (2^32 - 1) were
represented by negative numbers in the binary log. (Bug#37313
(http://bugs.mysql.com/bug.php?id=37313))

* *Replication*: The `--replicate-*-table' options were not
evaluated correctly when replicating multi-table updates.

As a result of this fix, replication of multi-table updates no
longer fails when an update references a missing table but does
not update any of its columns. (Bug#37051
(http://bugs.mysql.com/bug.php?id=37051))

* *Replication*: When its disk becomes full, a replication slave may
wait while writing the binary log, relay log or *Note `MyISAM':
myisam-storage-engine. tables, continuing after space has been
made available. The error message provided in such cases was not
clear about the frequency with which checking for free space is
done (once every 60 seconds), and how long the server waits after
space has been freed before continuing (also 60 seconds); this
caused users to think that the server had hung.

These issues have been addressed by making the error message
clearer, and dividing it into two separate messages:

1. The error message `Disk is full writing 'FILENAME' (Errcode:
ERROR_CODE). Waiting for someone to free space... (Expect up
to 60 secs delay for server to continue after freeing disk
space)' is printed only once.

2. The warning `Retry in 60 secs, Message reprinted in 600 secs'
is printed once every for every 10 times that the check for
free space is made; that is, the check is performed once each
60 seconds, but the reminder that space needs to be freed is
printed only once every 10 minutes (600 seconds).

(Bug#22082 (http://bugs.mysql.com/bug.php?id=22082))

* On 32-bit Windows, *Note `mysqld': mysqld. could not use large
buffers due to a 2GB user mode address limit. (Bug#43082
(http://bugs.mysql.com/bug.php?id=43082))

* The use by `libedit' of the `__weak_reference()' macro caused
compilation failure on FreeBSD. (Bug#42817
(http://bugs.mysql.com/bug.php?id=42817))

* Tables could enter open table cache for a thread without being
properly cleaned up, leading to a server crash. (Bug#42419
(http://bugs.mysql.com/bug.php?id=42419))

* *Note `mysqldumpslow': mysqldumpslow. parsed the `--debug' and
`--verbose' options incorrectly. (Bug#42027
(http://bugs.mysql.com/bug.php?id=42027))

* String reallocation could cause memory overruns. (Bug#41868
(http://bugs.mysql.com/bug.php?id=41868))

* Queries that used the loose index scan access method could return
no rows. (Bug#41610 (http://bugs.mysql.com/bug.php?id=41610))

* In `InnoDB' recovery after a server crash, rollback of a
transaction that updated a column from `NULL' to `NULL' could cause
another crash. (Bug#41571
(http://bugs.mysql.com/bug.php?id=41571))

* Use of `SELECT *' permitted users with rights to only some columns
of a view to access all columns. (Bug#41354
(http://bugs.mysql.com/bug.php?id=41354))

* The server did not robustly handle problems hang if a table opened
with *Note `HANDLER': handler. needed to be re-opened because it
had been altered to use a different storage engine that does not
support *Note `HANDLER': handler. The server also failed to set an
error if the re-open attempt failed. These problems could cause
the server to crash or hang. (Bug#41110
(http://bugs.mysql.com/bug.php?id=41110), Bug#41112
(http://bugs.mysql.com/bug.php?id=41112))

* For prepared statements, multibyte character sets were not taking
into account when calculating `max_length' for string values and
*Note `mysql_stmt_fetch()': mysql-stmt-fetch. could return
truncated strings. (Bug#41078
(http://bugs.mysql.com/bug.php?id=41078))

* The *Note `mysql_change_user()': mysql-change-user. C API function
changed the value of the `sql_big_selects' session variable.
(Bug#40363 (http://bugs.mysql.com/bug.php?id=40363)) See also
Bug#20023 (http://bugs.mysql.com/bug.php?id=20023).

* For a view that references a table in another database, *Note
`mysqldump': mysqldump. wrote the view name qualified with the
current database name. This makes it impossible to reload the dump
file into a different database. (Bug#40345
(http://bugs.mysql.com/bug.php?id=40345))

* *Note `perror': perror. did not produce correct output for error
codes 153 to 163. (Bug#39370
(http://bugs.mysql.com/bug.php?id=39370))

* Comparisons between row constructors, such as `(a, b) = (c, d)'
resulted in unnecessary `Illegal mix of collations' errors for
string columns. (Bug#37601
(http://bugs.mysql.com/bug.php?id=37601))

* An argument to the `MATCH()' function that was an alias for an
expression other than a column name caused a server crash.
(Bug#36737 (http://bugs.mysql.com/bug.php?id=36737))

* For *Note `DROP FUNCTION': drop-function. with names that were
qualified with a database name, the database name was handled in
case-sensitive fashion even with `lower_case_table_names' set to 1.
(Bug#33813 (http://bugs.mysql.com/bug.php?id=33813))

* *Note `mysqldump --compatible=mysql40': mysqldump. emitted
statements referring to the `character_set_client' system
variable, which is unknown before MySQL 4.1. Now the statements
are enclosed in version-specific comments. (Bug#33550
(http://bugs.mysql.com/bug.php?id=33550))

* Use of MBR spatial functions such as `MBRTouches()' with columns of
`InnoDB' tables caused a server crash rather than an error.
(Bug#31435 (http://bugs.mysql.com/bug.php?id=31435))

* The *Note `mysql': mysql. client mishandled input parsing if a
`delimiter' command was not first on the line. (Bug#31060
(http://bugs.mysql.com/bug.php?id=31060))

* *Note `SHOW PRIVILEGES': show-privileges. listed the `CREATE
ROUTINE' privilege as having a context of `Functions,Procedures',
but it is a database-level privilege. (Bug#30305
(http://bugs.mysql.com/bug.php?id=30305))

* *Note `SHOW TABLE STATUS': show-table-status. could fail to
produce output for tables with non-ASCII characters in their name.
(Bug#25830 (http://bugs.mysql.com/bug.php?id=25830))

* Floating-point numbers could be handled with different numbers of
digits depending on whether the text or prepared-statement
protocol was used. (Bug#21205
(http://bugs.mysql.com/bug.php?id=21205))

* Incorrect length metadata could be returned for `LONG TEXT'
columns when a multibyte server character set was used.
(Bug#19829 (http://bugs.mysql.com/bug.php?id=19829))

* `ROUND()' sometimes returned different results on different
platforms. (Bug#15936 (http://bugs.mysql.com/bug.php?id=15936))

File: manual.info, Node: news-5-0-78, Next: news-5-0-77, Prev: news-5-0-79, Up: news-5-0-x

D.1.18 Release Notes for MySQL Enterprise 5.0.78 [MRU] (06 February 2009)
-------------------------------------------------------------------------

This is a _Monthly Rapid Update_ release of the MySQL Enterprise Server
5.0.

This section documents all changes and bugfixes that have been applied
since the last MySQL Enterprise Server release (5.0.76). If you would
like to receive more fine-grained and personalized _update alerts_
about fixes that are relevant to the version and features you use,
please consider subscribing to _MySQL Enterprise_ (a commercial MySQL
offering). For more details please see
http://www.mysql.com/products/enterprise/advisors.html.

Bugs fixed:

* *Important Change*: When installing MySQL on Windows, it was
possible to install multiple editions (Complete, and Essential,
for example) of the same version of MySQL, leading to two separate
entries in the installed packages which were impossible to
isolate. This could lead to problems with installation and
uninstallation. The MySQL installer on Windows no longers permits
multiple installations of the same version of MySQL on a single
machine. (Bug#4217 (http://bugs.mysql.com/bug.php?id=4217))

* *MySQL Cluster*: *Packaging*: Packages for MySQL Cluster were
missing the `libndbclient.so' and `libndbclient.a' files.
(Bug#42278 (http://bugs.mysql.com/bug.php?id=42278))

* An optimization introduced for Bug#37553
(http://bugs.mysql.com/bug.php?id=37553) required an explicit cast
to be added for some uses of `TIMEDIFF()' because automatic
casting could produce incorrect results. (It was necessary to use
`TIME(TIMEDIFF(...))'.) (Bug#42525
(http://bugs.mysql.com/bug.php?id=42525))

* The SSL certficates included with MySQL distributions were
regenerated because the previous ones had expired. (Bug#42366
(http://bugs.mysql.com/bug.php?id=42366))

* Dependent subqueries such as the following caused a memory leak
proportional to the number of outer rows:

SELECT COUNT(*) FROM t1, t2 WHERE t2.b
IN (SELECT DISTINCT t2.b FROM t2 WHERE t2.b = t1.a);

(Bug#42037 (http://bugs.mysql.com/bug.php?id=42037))

* Some queries using `NAME_CONST(.. COLLATE ...)' led to a server
crash due to a failed type cast. (Bug#42014
(http://bugs.mysql.com/bug.php?id=42014))

* On Mac OS X, some of the universal client libraries were not
actually universal and were missing code for one or more
architectures. (Bug#41940
(http://bugs.mysql.com/bug.php?id=41940))

* `DATE_FORMAT()' could cause a server crash for year-zero dates.
(Bug#41470 (http://bugs.mysql.com/bug.php?id=41470))

* When substituting system constant functions with a constant
result, the server was not expecting `NULL' function return values
and could crash. (Bug#41437
(http://bugs.mysql.com/bug.php?id=41437))

* For a *Note `TIMESTAMP NOT NULL DEFAULT ...': datetime. column,
storing `NULL' as the return value from some functions caused a
`cannot be NULL' error. `NULL' returns now correctly cause the
column default value to be stored. (Bug#41370
(http://bugs.mysql.com/bug.php?id=41370))

* The Windows installer displayed incorrect product names in some
images. (Bug#40845 (http://bugs.mysql.com/bug.php?id=40845))

* The query cache stored only partial query results if a statement
failed while the results were being sent to the client. This could
cause other clients to hang when trying to read the cached result.
Now if a statement fails, the result is not cached. (Bug#40264
(http://bugs.mysql.com/bug.php?id=40264))

* The expression `ROW(...) IN (SELECT ... FROM DUAL)' always
returned `TRUE'. (Bug#39069
(http://bugs.mysql.com/bug.php?id=39069))

* The greedy optimizer could cause a server crash due to improper
handling of nested outer joins. (Bug#38795
(http://bugs.mysql.com/bug.php?id=38795))

* Use of `COUNT(DISTINCT)' prevented `NULL' testing in the `HAVING'
clause. (Bug#38637 (http://bugs.mysql.com/bug.php?id=38637))

* Enabling the `sync_frm' system variable had no effect on the
handling of `.frm' files for views. (Bug#38145
(http://bugs.mysql.com/bug.php?id=38145))

* The query cache stored packets containing the server status of the
time when the cached statement was run. This might lead to an
incorrect transaction status on the client side if a statement was
cached during a transaction and later served outside a transaction
context (or vice versa). (Bug#36326
(http://bugs.mysql.com/bug.php?id=36326))

* If the system time was adjusted backward during query execution,
the apparent execution time could be negative. But in some cases
these queries would be written to the slow query log, with the
negative execution time written as a large unsigned number. Now
statements with apparent negative execution time are not written
to the slow query log. (Bug#35396
(http://bugs.mysql.com/bug.php?id=35396))

* For *Note `mysqld_multi': mysqld-multi, using the
`--mysqld=mysqld_safe' option caused the `--defaults-file' and
`--defaults-extra-file' options to behave the same way.
(Bug#32136 (http://bugs.mysql.com/bug.php?id=32136))

* Attempts to open a valid MERGE table sometimes resulted in a
`ER_WRONG_MRG_TABLE' error. This happened after failure to open an
invalid MERGE table had also generated an `ER_WRONG_MRG_TABLE'
error. (Bug#32047 (http://bugs.mysql.com/bug.php?id=32047))

* The *Note `mysql_change_user()': mysql-change-user. C API function
caused global `Com_XXX' status variable values to be incorrect.
(Bug#31222 (http://bugs.mysql.com/bug.php?id=31222))

* For Solaris package installation using `pkgadd', the postinstall
script failed, causing the system tables in the `mysql' database
not to be created. (Bug#31164
(http://bugs.mysql.com/bug.php?id=31164))

* When installing the Windows service, using quotation marks around
command-line configuration parameters could cause the quotation
marks to be incorrectly placed around the entire command-line
option, and not just the value. (Bug#27535
(http://bugs.mysql.com/bug.php?id=27535))

File: manual.info, Node: news-5-0-77, Next: news-5-0-76, Prev: news-5-0-78, Up: news-5-0-x

D.1.19 Release Notes for MySQL Community Server 5.0.77 (28 January 2009)
------------------------------------------------------------------------

This is a bugfix release for the current MySQL Community Server
production release family. It replaces MySQL 5.0.67 (binary) and 5.0.75
(source-only).