MySQL中用通用查询日志找出查询次数最多的语句的教程

MySQL开启通用查询日志general log
mysql打开general log之后，所有的查询语句都可以在general log文件中以可读的方式得到，但是这样general log文件会非常大，所以默认都是关闭的。有的时候为了查错等原因，还是需要暂时打开general log的（本次测试只修改在内存中的参数值，不设置参数文件）。
general_log支持动态修改：

mysql> select version（）;

+-----------+| version（） |+-----------+| 5.6.16|+-----------+1 row in set （0.00 sec）

mysql> set global general_log=1;

Query OK, 0 rows affected （0.03 sec）

general_log支持输出到table：

mysql> set global log_output="TABLE";

Query OK, 0 rows affected （0.00 sec）

mysql> select * from mysql.general_logG;

*************************** 1. row *************************** event_time: 2014-08-14 10:53:18user_host: root[root] @ localhost []thread_id: 3server_id: 0command_type: Queryargument: select * from mysql.general_log*************************** 2. row *************************** event_time: 2014-08-14 10:54:25user_host: root[root] @ localhost []thread_id: 3server_id: 0command_type: Queryargument: select * from mysql.general_log2 rows in set （0.00 sec）ERROR: No query specified

输出到file：

mysql> set global log_output="FILE";

Query OK, 0 rows affected （0.00 sec）

mysql> set global general_log_file="/tmp/general.log";

Query OK, 0 rows affected （0.01 sec）

[root@mysql-db101 tmp]# more /tmp/general.log

/home/mysql/mysql/bin/mysqld, Version: 5.6.16 （Source distribution）. started with:Tcp port: 3306 Unix socket: /home/mysql/logs/mysql.sockTime Id CommandArgument140814 10:56:44 3 Query select * from mysql.general_log

查询次数最多的SQL语句

analysis-general-log.py general.log | sort | uniq -c | sort -nr

1032 SELECT * FROM wp_comments WHERE （ comment_approved = "x" OR comment_approved = "x" ） AND comment_post_ID = x ORDER BY comment_date_gmt DESC653 SELECT post_id, meta_key, meta_value FROM wp_postmeta WHERE post_id in （x） ORDER BY meta_id ASC527 SELECT FOUND_ROWS（）438 SELECT t.*, tt.* FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy = "x" AND t.term_id = x limit341 SELECT option_value FROM wp_options WHERE option_name = "x" limit329 SELECT t.*, tt.*, tr.object_id FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN wp_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy in （x） AND tr.object_id in （x） ORDER BY t.name ASC311 SELECT wp_posts.* FROM wp_posts WHERE 1= x AND wp_posts.ID in （x） AND wp_posts.post_type = "x" AND （（wp_posts.post_status = "x"）） ORDER BY wp_posts.post_date DESC219 SELECT wp_posts.* FROM wp_posts WHERE ID in （x）218 SELECT tr.object_id FROM wp_term_relationships AS tr INNER JOIN wp_term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy in （x） AND tt.term_id in （x） ORDER BY tr.object_id ASC217 SELECT wp_posts.* FROM wp_posts WHERE 1= x AND wp_posts.ID in （x） AND wp_posts.post_type = "x" AND （（wp_posts.post_status = "x"）） ORDER BY wp_posts.menu_order ASC202 SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts WHERE 1= x AND wp_posts.post_type = "x" AND （wp_posts.post_status = "x"） ORDER BY wp_posts.post_date DESC limit118 SET NAMES utf8115 SET SESSION sql_mode= "x"115 SELECT @@SESSION.sql_mode112 SELECT option_name, option_value FROM wp_options WHERE autoload = "x"111 SELECT user_id, meta_key, meta_value FROM wp_usermeta WHERE user_id in （x） ORDER BY umeta_id ASC108 SELECT YEAR（min（post_date_gmt）） AS firstdate, YEAR（max（post_date_gmt）） AS lastdate FROM wp_posts WHERE post_status = "x"108 SELECT t.*, tt.* FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy in （x） AND tt.count > x ORDER BY tt.count DESC limit107 SELECT t.*, tt.* FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy in （x） AND t.term_id in （x） ORDER BY t.name ASC107 SELECT * FROM wp_users WHERE ID = "x"106 SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts WHERE 1= x AND wp_posts.post_type = "x" AND （wp_posts.post_status = "x"） AND post_date > "x" ORDER BY wp_posts.post_date DESC limit106 SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts WHERE 1= x AND wp_posts.post_type = "x" AND （wp_posts.post_status = "x"） AND post_date > "x" ORDER BY RAND（） DESC limit105 SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts WHERE 1= x AND wp_posts.post_type = "x" AND （wp_posts.post_status = "x"） AND post_date > "x" ORDER BY wp_posts.comment_count DESC limit

PS：mysql general log日志清除技巧
mysql general log日志不能直接删除，间接方法

USE mysql;CREATE TABLE gn2 LIKE general_log;RENAME TABLE general_log TO oldLogs, gn2 TO general_log;