MySQL開啟通用查詢日志general log
mysql打開general log之后，所有的查詢語句都可以在general log文件中以可讀的方式得到，但是這樣general log文件會非常大，所以默認都是關閉的。有的時候為了查錯等原因，還是需要暫時打開general log的（本次測試只修改在內存中的參數值，不設置參數文件）。
general_log支持動態修改：
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支持輸出到table：
mysql> set global log_output='TABLE';
Query OK, 0 rows affected (0.00 sec)
mysql> select * from mysql.general_log/G;
*************************** 1. row *************************** event_time: 2014-08-14 10:53:18 user_host: root[root] @ localhost [] thread_id: 3 server_id: 0command_type: Query argument: select * from mysql.general_log*************************** 2. row *************************** event_time: 2014-08-14 10:54:25 user_host: root[root] @ localhost [] thread_id: 3 server_id: 0command_type: Query argument: select * from mysql.general_log2 rows in set (0.00 sec)ERROR: No query specified
輸出到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 Command Argument140814 10:56:44 3 Query select * from mysql.general_log
查詢次數最多的SQL語句
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日志不能直接刪除，間接方法
USE mysql;CREATE TABLE gn2 LIKE general_log;RENAME TABLE general_log TO oldLogs, gn2 TO general_log;
