开启Mysql慢查询

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mysql -urootWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 1588Server version: 5.6.35-log MySQL Community Server (GPL)Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>

设置成2秒，加上global,下次进mysql已然生效

mysql> set global long_query_time=2;Query OK, 0 rows affected (0.00 sec)mysql> show variables like 'long_query_time';+-----------------+----------+| Variable_name   | Value    |+-----------------+----------+| long_query_time | 1.000000 |+-----------------+----------+1 row in set (0.01 sec)

 查看一下慢查询是不是已经开启

说明：slow_query_log  OFF 说明慢查询还没有开启

mysql> show variables like "%slow%";+---------------------------+------------------------------+| Variable_name             | Value                        |+---------------------------+------------------------------+| log_slow_admin_statements | OFF                          || log_slow_slave_statements | OFF                          || slow_launch_time          | 2                            || slow_query_log            | OFF                          || slow_query_log_file       | /data/mysql/root-01-slow.log |+---------------------------+------------------------------+5 rows in set (0.00 sec)

启用慢查询

mysql> set global slow_query_log='ON';Query OK, 0 rows affected (0.22 sec)

 查看启用慢查询

说明：slow_query_log  ON 说明慢查询开启了

mysql> show variables like "%slow%";+---------------------------+------------------------------+| Variable_name             | Value                        |+---------------------------+------------------------------+| log_slow_admin_statements | OFF                          || log_slow_slave_statements | OFF                          || slow_launch_time          | 2                            || slow_query_log            | ON                           || slow_query_log_file       | /data/mysql/root-01-slow.log |+---------------------------+------------------------------+5 rows in set (0.00 sec)