mysql> show variables like 'general_log_file';
+------------------+------------------------------------+
| Variable_name    | Value                              |
+------------------+------------------------------------+
| general_log_file | /usr/local/mysql/data/localhost.log |
+------------------+------------------------------------+
1 row in set (0.00 sec)
错误日志文件路径
mysql> show variables like 'log_error';
+---------------+------------------------------------+
| Variable_name | Value                              |
+---------------+------------------------------------+
| log_error     | /usr/local/mysql/data/localhost.err |
+---------------+------------------------------------+
1 row in set (0.00 sec)
慢查询日志文件路径
mysql> show variables like 'slow_query_log_file';
+---------------------+-----------------------------------------+
| Variable_name       | Value                                   |
+---------------------+-----------------------------------------+
| slow_query_log_file | /usr/local/mysql/data/localhost-slow.log |
+---------------------+-----------------------------------------+
1 row in set (0.01 sec)

查看蛮查询是否开启OFF代表的是关闭

mysql> show variables like 'slow_query_log';

+----------------+-------+

| Variable_name  | Value |

+----------------+-------+

| slow_query_log | OFF   |

+----------------+-------+

1 row in set (0.01 sec)

①开启慢查询

②快慢时间临界点

mysql > show variables like 'long_query_time';

默认是10秒，我们给它设置成1秒

③设置时间临界点

mysql > set long_query_time = 2;  

设置的时候不需要加global。