On Tue, Sep 2, 2008 at 10:58 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > "Richard Broersma" <richard.broersma@xxxxxxxxx> writes: >> There is one possible alteration that may or many not improve >> performance. This would be to replace the EXISTS with a LEFT JOIN >> WHERE IS NOT NULL; > > That changes the behavior, doesn't it? Or is event_log_no a unique > key for Myevents? I think what you want is to make the EXISTS an IN > instead. Thanks for pointing that out Tom. I hadn't consider how the EXISTS clause would return potentially fewer rows if event_log_no wasn't unique. -- Regards, Richard Broersma Jr. Visit the Los Angeles PostgreSQL Users Group (LAPUG) http://pugs.postgresql.org/lapug
