MySQL 设置慢查询为200ms

1：查看当前版本并设置long_query_time为0.2

mysql> select version();
+------------+
| version()  |
+------------+
| 5.1.73-log |
+------------+
1 row in set (0.00 sec)

mysql> set global long_query_time =0.2;
Query OK, 0 rows affected (0.00 sec)

　　

2：另外新建一个连接

mysql> show variables like '%long_query_time%';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 0.200000 |
+-----------------+----------+
1 row in set (0.00 sec)

mysql> select sleep(1);
+----------+
| sleep(1) |
+----------+
|        0 |
+----------+
1 row in set (0.99 sec)

　　

3：系统上查看慢查询日志

[root@used ~]# tail /var/log/mysql-slow.log

Time                 Id Command    Argument
# Time: 150421 14:59:11
# User@Host: root[root] @ localhost []
# Query_time: 1.000273  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 0
SET timestamp=1429599551;
select sleep(1);