使用MySQL的Performance Schema

1.查看performance_schema

show variables like 'Performance_schema%';

2.查看存储引擎的状态显示总内存大小

show engine performance_schema status;

3.进入performance_schema,执行select语句setup_开头的表

use performance_schema;

show tables like 'setup\_%';

4.监控前台线程，前台线程是与客户端连接关联的线程。(那些用户需要收集信息)

select * from setup_actors;

5.那些对象需要收集信息，比如mysql表

select * from setup_objects;

6.计时定义表

select * from setup_timers;

7.收集仪器，每一个功能点都会有仪器的事件，开始和结束，然后开启那个仪器，就会收集那个仪器的数据

select * from setup_instruments;

8.那些仪器的分类需要收集

select * from setup_consumers;

9.看帮助文档

select * from table_io_waits_summary_by_table;

10.校验instruments是否启用

select * from setup_instruments where name like 'wait/io/table%';

1. truncate table_io_waits_summary_by_table表

   truncate table table_io_waits_summary_by_table;

12.执行employees数据库

select * from employees.employees;

13.查object_schema,object_name,count_star,sum_timer_wait字段

select object_schema,object_name,count_star,sum_timer_wait

from table table_io_waits_summary_by_table

where object_schema='employees'

and object_name='employees';

14.执行以下查询

select sleep(5);

15.查询sys用户下的statments_with_runtimes_in_95th_percentile

select * from sys.statments_with_runtimes_in_95th_percentile\G