使用MySQL的Performance Schema

1.檢視performance_schema

show variables like 'Performance_schema%';

2.檢視存儲引擎的狀态顯示總記憶體大小

show engine performance_schema status;

3.進入performance_schema,執行select語句setup_開頭的表

use performance_schema;

show tables like 'setup\_%';

4.監控前台線程，前台線程是與用戶端連接配接關聯的線程。(那些使用者需要收集資訊)

select * from setup_actors;

5.那些對象需要收集資訊，比如mysql表

select * from setup_objects;

6.計時定義表

select * from setup_timers;

7.收集儀器，每一個功能點都會有儀器的事件，開始和結束，然後開啟那個儀器，就會收集那個儀器的資料

select * from setup_instruments;

8.那些儀器的分類需要收集

select * from setup_consumers;

9.看幫助文檔

select * from table_io_waits_summary_by_table;

10.校驗instruments是否啟用

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.執行employees資料庫

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.執行以下查詢

select sleep(5);

15.查詢sys使用者下的statments_with_runtimes_in_95th_percentile

select * from sys.statments_with_runtimes_in_95th_percentile\G