Re: MERGE: performance advices - Mailing list pgsql-general

"Richard Broersma" <richard.broersma@gmail.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