Re: mySQL table joins are slow, need rebuild?

On Tue, 27 Feb 2001 15:04:09 -0800, Joe Stump (jstump@zebulon.miester.org) wrote: >You need to remember a few things when it comes to joins: > >the joined fields must be the EXACT same definition > - example: a join on id int(9) and id int(3) will NOT be optimized > - more: a join on id char(9) and id int(9) is REALLY NOT optimized >:O) true, but even more important than this is to make sure there's an index on both fields. without that it will crawl. also if the 'order by' is causing problems you might want to up the tmp_table_size in my.cnf, and very important is to not let the partition that tmp is on get too full. - Mark