MySQL Slow query log configuration method detailed

To see if the MySQL server's slow query status is turned on:

1	show variables like'%slow%';

• Slow_launch_time, which means more than 2 seconds is defined as a slow query
• Log_slow_queries and Slow_query_log, indicating that the slow query has been opened
• Slow_query_log_file, the location of the file that represents the slow query log

In the MySQL configuration file my.cnf or my.ini [mysqld] Add the slow query configuration statement settings to open the slow query state :

1	#定义超过指定时间（秒）的查询，可用小数

2	long_query_time = 2

3	#定义慢查询日志路径（此目录文件一定要有写权限）

4	log-slow-queries=C:/slowquery.log

5	#未使用索引的查询也被记录到慢查询日志中

6	log-queries-not-using-indexes

Once configured, restart MySQL, the MySQL server's slow query status has been opened:

Of course, you can also use the SET command to set the state of a MySQL variable, but this setting is temporary:

1	setglobalslow_query_log=on; #开启

2	setglobalslow_query_log=off; #关闭

Precautions:

Slow query time should not be set too long, otherwise not very meaningful