On Tue, Jul 27, 2010 at 7:27 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> Does it help if you put a CHECK (false) constraint on the parent table? > > It won't --- it'll still result in an append plan even if there's only > one surviving child. > > This is one of many things that seem to me to not make sense to tackle > until we have an explicit notion of partitioning. Having the planner > try to prove from individual constraints that it could get a correctly > sorted Append result without an explicit sort step would be hugely > expensive, and complicated --- imagine even trying to pick out the > relevant indexes without any infrastructure to help identify them. > With a partitioned structure we could understand that a-priori.
Hmm, I thought we had something that made it behave more like the non-partitioned case when there is only one surviving partition. But I agree that, perhaps apart from that special case, there's not much hope of improving this until we have more infrastructure. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
