MySQL之Show Profiles

definition

Show Profiles is provided by MySQL, which can analyze the resource consumption of SQL statement execution and can be used for SQL tuning.
SQL profiling is enabled by configuring the profiling parameter, which can be set globally and at the session level.
The global level affects the entire MySQL instance, while the session level only affects the current session.
After this parameter is turned on, the subsequent execution of SQL statements will record its resource overhead, such as IO, context switching, CPU, Memory, etc.
Show profiles were added after 5.0.37. To use this feature, make sure that the MySQL version is> 5.0.37.

how to use

select version(); -- 查看数据库版本
show variables like "%profiling%"; -- 查看是否开启
set profiling=1; -- 开启profile
show profiles; -- 查看最近的SQL语句

Help document

help profile;  --查看帮助信息

SHOW PROFILE [type [, type] ... ]
    [FOR QUERY n]
    [LIMIT row_count [OFFSET offset]]

type: {
    ALL                 --显示所有的开销信息  
  | BLOCK IO           --显示块IO相关开销  
  | CONTEXT SWITCHES   --上下文切换相关开销  
  | CPU                --显示CPU相关开销信息  
  | IPC                --显示发送和接收相关开销信息  
  | MEMORY             --显示内存相关开销信息  
  | PAGE FAULTS        --显示页面错误相关开销信息  
  | SOURCE             --显示和Source_function，Source_file，Source_line相关的开销信息  
  | SWAPS              --显示交换次数相关开销的信息   
}
*Note*:

The SHOW PROFILE and SHOW PROFILES statements are deprecated and will
be removed in a future MySQL release. Use the Performance Schema
instead; see
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-query-profil
ing.html

--上面描述SHOW PROFILE命令将会被移除，推荐用Performance Schema instead代替  
--在Oracle数据库中，是通过autotrace来剖析单条SQL并获取真实的执行计划以及其开销信息

URL: https://dev.mysql.com/doc/refman/8.0/en/show-profile.html

Official website

Performance Schema description document: https://dev.mysql.com/doc/refman/8.0/en/performance-schema-query-profiling.html
SHOW PROFILE description document: https://dev.mysql.com/doc/refman /8.0/en/show-profile.html

show profile for query 167;  -- 获取指定查询(Query_ID = 167)的开销
-- 查看特定部分的开销，如下为CPU部分的开销  
show profile cpu for query 167 ;
-- 如下为MEMORY部分的开销  
show profile memory for query 167 ; 
-- 同时查看io和cpu
show profile block io,cpu for query 167;  
-- 下面的SQL语句用于查询query_id为2的SQL开销，且按最大耗用时间倒序排列  
set @query_id=167;