config root man

#
# Bug #19183565 CREATE DYNAMIC INNODB_TMPDIR VARIABLE TO CONTROL
#		WHERE INNODB WRITES TEMP FILES
#
# If innodb_tmpdir is NULL or "", temporary file will be created in
# server configuration variable location(--tmpdir)
create table t1(a int primary key)engine=innodb;
show session variables like 'innodb_tmpdir';
Variable_name	Value
innodb_tmpdir	
alter table t1 add column b int not null;
set global innodb_tmpdir=NULL;
# Connection con1
show session variables like 'innodb_tmpdir';
Variable_name	Value
innodb_tmpdir	
alter table t1 add key(b);
drop table t1;
# innodb_tmpdir with invalid path.
create table t1(a int primary key)engine=innodb;
set global innodb_tmpdir='wrong_value';
ERROR 42000: Variable 'innodb_tmpdir' can't be set to the value of 'wrong_value'
show warnings;
Level	Code	Message
Warning	1210	InnoDB: Path doesn't exist.
Error	1231	Variable 'innodb_tmpdir' can't be set to the value of 'wrong_value'
drop table t1;
# innodb_tmpdir with mysql data directory path.
create table t1(a text, b text, fulltext(a,b))engine=innodb;
insert into t1 values('test1', 'test2');
insert into t1 values('text1', 'text2');
set global innodb_tmpdir = @@global.datadir;
ERROR 42000: Variable 'innodb_tmpdir' can't be set to the value of 'MYSQL_DATADIR'
show warnings;
Level	Code	Message
Warning	1210	InnoDB: Path location should not be same as mysql data directory location.
Error	1231	DATADIR/data/'
drop table t1;
# innodb_tmpdir with valid location.
create table t1(a text, b text, fulltext(a,b))engine=innodb;
insert into t1 values('test1', 'test2');
insert into t1 values('text1', 'text2');
set @tmpdir = @@global.tmpdir;
set global innodb_tmpdir = @tmpdir;
show session variables like 'innodb_tmpdir';
Variable_name	Value
innodb_tmpdir	
# Connection con3
alter table t1 add fulltext(b);
set global innodb_tmpdir=NULL;
drop table t1;