Tom Lane wrote: > Alvaro Herrera <alvhe...@2ndquadrant.com> writes: > > Tom Lane wrote: > >> Alvaro Herrera <alvhe...@2ndquadrant.com> writes: > >>> Won't this cause issues to MergeAppend optimizations? > > >> Like what? > > > Well, as I understand, MergeAppend needs to know the sort order of the > > child node, right? But that's available only on the relation RTE, not > > on the colstore-join RTE. > > Uh, what? Sort order is a property of a path, not an RTE.
Evidently need to do more digging .. but that makes plenty of sense. > And we have always understood which join types preserve sort order. That's obvious now that you say it. > You misunderstood the thrust of my comment, which basically is that > I doubt anyone will think that rejecting that combination is an > acceptable implementation restriction. It might be all right if it > doesn't work very well in v0, but not if the implementation is designed > so that it can never be fixed. Gotcha. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
