On Fri, Sep 29, 2017 at 7:48 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: > I think in general the non-partial paths should be cheaper as compared > to partial paths as that is the reason planner choose not to make a > partial plan at first place. I think the idea patch is using will help > because the leader will choose to execute partial path in most cases > (when there is a mix of partial and non-partial paths) and for that > case, the leader is not bound to complete the execution of that path. > However, if all the paths are non-partial, then I am not sure much > difference it would be to choose one path over other.
The case where all plans are non-partial is the case where it matters most! If the leader is going to take a share of the work, we want it to take the smallest share possible. It's a lot fuzzier what is best when there are only partial plans. -- 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
