2015/03/26 10:51、Kouhei Kaigai <kai...@ak.jp.nec.com> のメール： > The attached patch adds GetForeignJoinPaths call on make_join_rel() only when > 'joinrel' is actually built and both of child relations are managed by same > FDW driver, prior to any other built-in join paths. > I adjusted the hook definition a little bit, because jointype can be > reproduced > using SpecialJoinInfo. Right?
OK. > > Probably, it will solve the original concern towards multiple calls of FDW > handler in case when it tries to replace an entire join subtree with a > foreign- > scan on the result of remote join query. > > How about your opinion? Seems fine. I’ve fixed my postgres_fdw code to fit the new version, and am working on handling a whole-join-tree. It would be difficult in the 9.5 cycle, but a hook point where we can handle whole joinrel might allow us to optimize a query which accesses multiple parent tables, each is inherited by foreign tables and partitioned with identical join key, by building a path tree which joins sharded tables first, and then union those results. -- Shigeru HANADA shigeru.han...@gmail.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
