On Sat, Aug 12, 2017 at 9:18 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: > I think skipping a generation of gather paths for scan node or top > level join node generated via standard_join_search seems straight > forward, but skipping for paths generated via geqo seems to be tricky > (See use of generate_gather_paths in merge_clump). Assuming, we find > some way to skip it for top level scan/join node, I don't think that > will be sufficient, we have some special way to push target list below > Gather node in apply_projection_to_path, we need to move that part as > well in generate_gather_paths.
I don't think that can work, because at that point we don't know what target list the upper node wants to impose. -- 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
