Hanada-san, Your patch mixtures enhancement of custom-/foreign-scan interface and enhancement of contrib/postgres_fdw... Probably, it is a careless mis- operation. Please make your patch as differences from my infrastructure portion.
Also, I noticed this "Join pushdown support for foreign tables" patch is unintentionally rejected in the last commit fest. https://commitfest.postgresql.org/3/20/ I couldn't register myself as reviewer. How do I operate it on the new commitfest application? Thanks, -- NEC OSS Promotion Center / PG-Strom Project KaiGai Kohei <kai...@ak.jp.nec.com> > -----Original Message----- > From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Shigeru Hanada > Sent: Monday, February 16, 2015 1:03 PM > To: Robert Haas > Cc: PostgreSQL-development > Subject: Re: [HACKERS] Join push-down support for foreign tables > > Hi > > I've revised the patch based on Kaigai-san's custom/foreign join patch > posted in the thread below. > > http://www.postgresql.org/message-id/9A28C8860F777E439AA12E8AEA7694F80 > 108c...@bpxm15gp.gisp.nec.co.jp > > Basically not changed from the version in the last CF, but as Robert > commented before, N-way (not only 2-way) joins should be supported in the > first version by construct SELECT SQL by containing source query in FROM > clause as inline views (a.k.a. from clause subquery). > > 2014-12-26 13:48 GMT+09:00 Shigeru Hanada <shigeru.han...@gmail.com>: > > 2014-12-16 1:22 GMT+09:00 Robert Haas <robertmh...@gmail.com>: > >> On Mon, Dec 15, 2014 at 3:40 AM, Shigeru Hanada > >> <shigeru.han...@gmail.com> wrote: > >>> I'm working on $SUBJECT and would like to get comments about the > >>> design. Attached patch is for the design below. > >> > >> I'm glad you are working on this. > >> > >>> 1. Join source relations > >>> As described above, postgres_fdw (and most of SQL-based FDWs) needs > >>> to check that 1) all foreign tables in the join belong to a server, > >>> and > >>> 2) all foreign tables have same checkAsUser. > >>> In addition to that, I add extra limitation that both inner/outer > >>> should be plain foreign tables, not a result of foreign join. This > >>> limiation makes SQL generator simple. Fundamentally it's possible > >>> to join even join relations, so N-way join is listed as enhancement > >>> item below. > >> > >> It seems pretty important to me that we have a way to push the entire > >> join nest down. Being able to push down a 2-way join but not more > >> seems like quite a severe limitation. > > > > Hmm, I agree to support N-way join is very useful. Postgres-XC's SQL > > generator seems to give us a hint for such case, I'll check it out > > again. > > > > -- > > Shigeru HANADA > > > > -- > Shigeru HANADA -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
