MySql慢查询日志——开启/查看/删除

1,开启慢查询日志

修改mysql.ini文件，加入如下配置：

[mysqld]
log-slow-queries=H:\mysql_log\slow_query.log
long-query-time=3

set global slow_query_log=ON;

set global slow_launch_time=5;

show variables like "%slow%";

设置查询日志的存储位置，慢查询时间。

show variables like '%slow%'; /*查看慢查询配置*/

show variables like "long_query_time"; /*查看慢查询时间*/

show status like "%slow_queries%";/*查看慢查询配置情况*/

2，查看慢查询

打开log文件：

F:\mysql\bin\mysqld, Version: 5.5.24-log (MySQL Community Server (GPL)). started with:
TCP Port: 3306, Named Pipe: (null)
Time                 Id Command    Argument
# Time: 161008 21:20:02
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 8.718499  Lock_time: 0.001002 Rows_sent: 0  Rows_examined: 908972
use energy;
SET timestamp=1475932802;
/*结束时间*/
									


select 

DATE_FORMAT(worker_order.create_time,'%Y-%m-%d') as create_time,/*创建时间*/
(	select count(0) 
		from biz_work_order tmp 
		where 
		DATE_FORMAT(tmp.create_time,'%Y-%m-%d')=DATE_FORMAT(worker_order.create_time,'%Y-%m-%d')
		or (tmp.create_time

被自己写的SQL慢哭了。。。

三，删除慢查询日志

直接delete掉log,删除后需要执行下面两句中的任意一句，重新生成日志文件：

  -> mysqladmin -u root-p flush-logs
    -> flush logs