On 11/21/2012 12:06 AM, Claudio Freire wrote: > I meant for postgres to do automatically. Rewriting as a join wouldn't > work as an optimization fence the way we're used to, but pushing > constraints upwards can only help (especially if highly selective). Because people are now used to using CTEs as query hints, it'd probably cause performance regressions in working queries. Perhaps more importantly, Pg would have to prove that doing so didn't change queries that invoked functions with side-effects to avoid changing the results of currently valid queries. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
