????MySQL?????????????λ???Ч?????SQL????????????????????????????mysqldumpslow?????MySQL???????????????????????????з???????
????MySQL?????????????λ??Щ???Ч?????SQL ?????--log-slow-queries[=file_name]?????????mysqld ??д???????????????????long_query_time ???SQL????????????????????????????λЧ?????SQL ??
????????????????????????????????????÷?????Ч??????????????????????????????λ???????????show processlist????????MySQL????е???????????????????????????????????SQL ???????????????Щ????????????????
????????????????????￡?????????????????λ???Ч????SQL ???
??????????????????????????:
????[mysqld] 
????log-slow-queries
??????my.cnf ???????????????????????????mysql???????mysql???????????Ч????????????д??????DATADIR???????????????·???￡???????????host_name-slow.log ??
?????????????????????????????????????????????????????????????????????????????????????ú????????
????????????? long_query_time ??? ??
????mysql> show variables like 'long%'; 
????+-----------------+-------+ 
????| Variable_name | Value | 
????+-----------------+-------+ 
????| long_query_time | 10 | 
????+-----------------+-------+ 
????1 row in set (0.00 sec)
????????????????????????????5??
????mysql> set long_query_time=5; 
????Query OK?? 0 rows affected (0.02 sec)
?????????????????????????
????????????????????????5 ?????????????????????У?
????mysql> select count(*) from order2008; 
????+----------+ 
????| count(*) | 
????+----------+ 
????| 208 | 
????+----------+ 
????1 row in set (0.00 sec)
????????????????????????5 ?????ó??????????????У?
????mysql> select count(*) from t_user; 
????+----------+ 
????| count(*) | 
????+----------+ 
????| 6552961 |
????????????????
????[root@localhost mysql]# more localhost-slow.log 
????# Time: 081026 19:46:34 
????# User@Host: root[root] @ localhost [] 
????# Query_time: 11 Lock_time: 0 Rows_sent: 1 Rows_examined: 6552961 
????select count(*) from t_user;
??????????????У???????????????5 ???SQL????С??5???????г??????????С?
????????????????м???????????????mysqldumpslow?????MySQL???????????????????????????з????????????ж???????mysql_master-slow.log?????????????????????????????
????[root@mysql_master mysql_data]#mysqldumpslow mysql_master-slow.log 
????Reading mysql slow query log from mysql_master-slow.log 
????Count: 2 Time=11.00s (22s) Lock=0.00s (0s) Rows=1.0 (2)?? root[root]@mysql_master 
????select count(N) from t_user;
???????? SQL ????????￡???????????????mysqldumpslow ???????????????????????????????N?????檔?????????????????????????????????Ч?????????λ????SQL ?????
??????????????????????????????????????????SQL???а?????????????????￡??????????????????????