config root man

#
# Bug#12427262 : 60961: SHOW TABLES VERY SLOW WHEN NOT IN SYSTEM DISK CACHE. 
#
create database show_table_lw_db;
use show_table_lw_db;
create table t1 (c1 int);
create table t2 (c1 int);
create table t3 (c1 int);
create table t4 (c1 int);
create table t5 (c1 int);
create table t6 (c1 int);
create table t7 (c1 int);
create table t8 (c1 int);
create table t9 (c1 int);
create table t10 (c1 int);
# Query PS to know initial read count for frm file.
select Sum(ALL(COUNT_READ)) from performance_schema.file_summary_by_instance where FILE_NAME 
like "%show_table_lw_db%" AND FILE_NAME like "%.frm%" AND EVENT_NAME='wait/io/file/sql/FRM'
into @count_read_before;
show tables;
Tables_in_show_table_lw_db
t1
t10
t2
t3
t4
t5
t6
t7
t8
t9
# Query PS to know read count for frm file after above query. It should
# not be changed as FRM file will not be opened for above query.
select Sum(ALL(COUNT_READ)) from performance_schema.file_summary_by_instance where FILE_NAME 
like "%show_table_lw_db%" AND FILE_NAME like "%.frm%" AND EVENT_NAME='wait/io/file/sql/FRM'
into @count_read_after;
select @count_read_after-@count_read_before;
@count_read_after-@count_read_before
0.000000000000000000000000000000
show full tables;
Tables_in_show_table_lw_db	Table_type
t1	BASE TABLE
t10	BASE TABLE
t2	BASE TABLE
t3	BASE TABLE
t4	BASE TABLE
t5	BASE TABLE
t6	BASE TABLE
t7	BASE TABLE
t8	BASE TABLE
t9	BASE TABLE
# Query PS to know read count for frm file after above query. COUNT_READ
# will be incremented by 1 as FRM file will be opened for above query.
select Sum(ALL(COUNT_READ)) from performance_schema.file_summary_by_instance where FILE_NAME 
like "%show_table_lw_db%" AND FILE_NAME like "%.frm%" AND EVENT_NAME='wait/io/file/sql/FRM'
into @count_read_after;
select @count_read_after-@count_read_before;
@count_read_after-@count_read_before
10.000000000000000000000000000000
drop table t1;
drop database show_table_lw_db;