应用错误收集

可能重复：
How can “set timestamp” be a slow query?

我使用PHP和MySQL 5.1运行Web应用程序和Wordpress博客，驻留在VPS服务器上。慢查询日志显示了许多条目，这些条目不应该花费很长时间才能完成。奇怪的是，当我点击我的博客链接时，通常需要很长时间才能加载，但之后很快就会加载。然后在几个小时内再次回到慢速第一次点击。似乎“SET timestamp =”查询几乎存在于所有慢速条目中。以下是它的外观示例：

# Time: 110129  4:02:06
# User@Host: appsadmin[appsadmin] @ localhost []
# Query_time: 1.367264  Lock_time: 0.000043 Rows_sent: 18  Rows_examined: 18
use apps;
SET timestamp=1296291726;
show tables;
# Time: 110129  4:02:07
# User@Host: wp_user[wp_user] @ localhost []
# Query_time: 0.635450  Lock_time: 0.000041 Rows_sent: 11  Rows_examined: 11
use wordpress_user;
SET timestamp=1296291727;
show tables;
# Time: 110130  4:02:03
# User@Host: appsadmin[appsadmin] @ localhost []
# Query_time: 0.592159  Lock_time: 0.000000 Rows_sent: 0  Rows_examined: 0
use apps;
SET timestamp=1296378123;
SELECT /*!40001 SQL_NO_CACHE */ * FROM `mail_queue`;
# Time: 110131  4:02:08
# User@Host: appsadmin[appsadmin] @ localhost []
# Query_time: 2.789990  Lock_time: 0.000047 Rows_sent: 18  Rows_examined: 18
SET timestamp=1296464528;
show tables;
# Time: 110131  4:02:09
# User@Host: wp_user[wp_user] @ localhost []
# Query_time: 0.535981  Lock_time: 0.000041 Rows_sent: 11  Rows_examined: 11
use wordpress_user;
SET timestamp=1296464529;
show tables;
# Time: 110201  3:19:03
# User@Host: wp_user[wp_user] @ localhost []
# Query_time: 1.401393  Lock_time: 0.000071 Rows_sent: 120  Rows_examined: 145
SET timestamp=1296548343;
SELECT option_name, option_value FROM wp_options WHERE autoload = 'yes';

这表明它不是我的数据库设计的问题，而是某种配置问题。

MySQL SET时间戳作为慢速查询

1 个答案: