环境：

  操作系统： CentOS  6.5

  数据库：    mysql-5.1.73

1、查看当前慢查询配置

mysql> show variables like 'slow%';+---------------------+---------------------------------+| Variable_name       | Value                           |+---------------------+---------------------------------+| slow_launch_time    | 2                               || slow_query_log      | OFF                             || slow_query_log_file | /var/run/mysqld/mysqld-slow.log |+---------------------+---------------------------------+3 rows in set (0.00 sec)

2、通过修改 my.cnf 开启监听慢查询

vi /etc/my.cnf  添加配置[mysqld]log-slow-queries = /var/lib/mysql/sql_slow.log#单位秒long_query_time = 1log-queries-not-using-indexes

3、重新启动 mysql

service mysqld restart

4、查看配置是否生效

mysql> show variables like 'slow%';+---------------------+-----------------------------+| Variable_name       | Value                       |+---------------------+-----------------------------+| slow_launch_time    | 2                           || slow_query_log      | ON                          || slow_query_log_file | /var/lib/mysql/sql_slow.log |+---------------------+-----------------------------+3 rows in set (0.00 sec)

5、测试日志是否记录

执行SQL:

select sleep(3);

  查看记录日志 tail  -300f  sql_slow.log 

 Query_time :查询使用时间

Lock_time:锁时间

Rows_sent：返回记录条数

Rows_examined：总共记录条数

Tcp port: 3306  Unix socket: /var/lib/mysql/mysql.sock    Time                 Id Command    Argument    # Time: 151019 15:39:04    # User@Host: [root] @ localhost []    # Query_time: 3.001364  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 0    SET timestamp=1445240344;    select sleep(3);