On Thu, Jan 26, 2012 at 2:27 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >>>> Is there a guard in here against joining a parameterized path to an >>>> intermediate relation when no SJ is involved? In other words, if >>>> we're joining a parameterized path on A to a path on B, then either >>>> the join to B should satisfy at least part of the parameterization >>>> needed by A, or there should be a special join with A and B on one >>>> side and a relation that satisfies at least part of the >>>> parameterization of A on the other. > > I've implemented this idea, recast a bit to prevent generating a > parameterized join path in the first place unless it depends on a > parameter from a relation for which there's a join ordering constraint > still outstanding. It seems to get us to where the planning time > penalty is only about 10%, which frankly is probably less than sampling > error considering the small set of test cases I'm looking at.
Awesome. If you can post the updated patch, I'll poke at it a little more and see if anything jumps out at me, but that sounds promising. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers