"Richard Broersma" <richard(dot)broersma(at)gmail(dot)com> 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.
regards, tom lane