On Mon, Mar 1, 2010 at 2:29 PM, Anj Adu <fotogra...@gmail.com> wrote: > When I use intervals in my query e.g col1 between current_timestamp - > interval '10 days' and current_timestamp...the optimizer checks ALL > partitions whereas if I use col1 between 2 hardcoded dates..only > the applicable partitions are scanned.
Yep. This is one example of a more general principle: constant-folding happens before planning, but anything more complex has to wait until execution time. So the plan can't take into account the value of current_timestamp in forming the plan. Unfortunately I don't think there's really any easy way around this: you have to do select current_timestamp, current_timestamp - interval '10 days' first and then build & execute a new query. ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
