On Tue, Feb 3, 2009 at 12:24 PM, Jerry Schwartz <jschwa...@the-infoshop.com> wrote: > Somebody, I think it was somebody from MySQL, said that you should never put > anything into a WHERE clause that could be put into the ON clause of a JOIN. > My guess is that this helps with the optimization, but it seems > counter-intuitive to me.
It seems like it shouldn't make any difference if the optimizer is smart enough, but in my experience it sometimes does. Because of that, I always try to put conditions in the ON clauses when I can, even if they are not about joining the tables. - Perrin -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
