Hi. I think you should create an index like this. alter table user add index idx_tmp (key1,key2,key3,user_id)
2009/6/19 Darryle Steplight <dstepli...@gmail.com> > Select user_id from user where key1=value and > key2=value2 and key3=value2 GROUP BY user_id > > is faster than > > > Select distinct user_id from user where key1=value and > key2=value2 and key3=value2; > > > 2009/6/18 周彦伟 <yanwei.z...@opi-corp.com>: > > Hi, > > I have a sql : > > Select distinct user_id from user where key1=value and > > key2=value2 and key3=value2; > > > > I add index on (key1,key2,key3,user_id), this sql use temporary table > > howevery > > I have thousands of queries per second. > > How to optimize it? > > > > > > Anthoer question: > > Select * from user where user_id in(id1,id2,id3,id4,.....) order by > use_id; > > I add index on user_id,but after in,order use temporary table, How to > > optimize it? > > > > Thanks! > > > > zhouyanwei > > > > > > > > -- > > MySQL General Mailing List > > For list archives: http://lists.mysql.com/mysql > > To unsubscribe: > http://lists.mysql.com/mysql?unsub=dstepli...@gmail.com > > > > > > > > -- > A: It reverses the normal flow of conversation. > Q: What's wrong with top-posting? > A: Top-posting. > Q: What's the biggest scourge on plain text email discussions? > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/mysql?unsub=yueliangdao0...@gmail.com > > -- David Yeung, MySQL Senior Support Engineer, Sun Gold Partner. My Blog:http://yueliangdao0608.cublog.cn
