On Wed, Dec 16, 2015 at 5:59 AM, David Rowley <david.row...@2ndquadrant.com> wrote: > One thing I noticed is that you're only enabling Parallel aggregation when > there's already a Gather node in the plan. Perhaps this is fine for a proof > of concept, but I'm wondering how we can move forward from this to something > that can be committed.
As far as that goes, I think the infrastructure introduced by the parallel join patch will be quite helpful here. That introduces the concept of a "partial path" - that is, a path that needs a Gather node in order to be completed. And that's exactly what you need here: after join planning, if there's a partial path available for the final rel, then you can consider FinalizeAggregate->Gather->PartialAggregate->[the best partial path]. Of course, whether a partial path is available or not, you can consider Aggregate->[the best regular old path]. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
