Yeah. The subquery sometimes creates temporary tables, so the performance is worse than join. Just leaving it. David Yeung, In China, Beijing. My First Blog:http://yueliangdao0608.cublog.cn My Second Blog:http://yueliangdao0608.blog.51cto.com My Msn: yueliangdao0...@gmail.com
2010/12/8 Aaron Turner <synfina...@gmail.com> > Thanks Gavin. Rewriting the query to not use the subselect solved the > problem! > > On Tue, Dec 7, 2010 at 11:33 AM, Gavin Towey <gto...@ffn.com> wrote: > > Mysql often handles subqueries poorly. It's best to rewrite that as a > JOIN instead: > > > > http://dev.mysql.com/doc/refman/5.1/en/rewriting-subqueries.html > > > > If you have further questions after doing that, show the table > structures, the query, and the explain output. > > > > -- > Aaron Turner > http://synfin.net/ Twitter: @synfinatic > http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & > Windows > Those who would give up essential Liberty, to purchase a little temporary > Safety, deserve neither Liberty nor Safety. > -- Benjamin Franklin > "carpe diem quam minimum credula postero" > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/mysql?unsub=yueliangdao0...@gmail.com > >
