Chris, The good news is that MySQL 5.0 can finally use multiple indexes per table. I just noticed this page in the manual a few days ago: http://www.mysql.com/doc/en/OR_optimizations.html
:-) Matt ----- Original Message ----- From: "Chris Nolan" Sent: Monday, February 16, 2004 7:13 AM Subject: Re: Indexed searching with OR ? > Hi! > > MySQL's optimizer has a slight problem. OR queries cause it to get very > confused. > > Try the following to get the best performance: > > Rewrite SELECT FROM table WHERE (condition1) OR (condition2); > > As: > > (SELECT FROM table WHERE condition1) UNION (SELECT FROM table WHERE > condition2); > > Hope this helps! > > Regards, > > Chris > > On Tue, 2004-02-17 at 00:05, Andreas Pardeike wrote: > > Hi List, > > > > Can someone explain the results below? It seems that MySQL has a hard > > time choosing keys for 'or' searches. The example here is very simple > > but reflects the more complex cases where lots of rows or joins are > > used perfectly: > > <snip> > > > > What's the point of indices if I cannot combine two indexed fields with > > OR ? > > > > Any help appreciated, > > Andreas Pardeike -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
