On Thu, Mar 17, 2016 at 7:00 AM, Etsuro Fujita <fujita.ets...@lab.ntt.co.jp> wrote: > BUT: we don't make any effort to ensure that local and remote values > match, so system columns other than ctid and oid should not be retrieved > from the remote server.
I agree. > So, I'd like to propose: (1) when tableoids are > requested from the remote server, postgres_fdw sets valid values for > them locally, instead (core should support that?) Sure. > and (2) when any of > xmins, xmaxs, cmins, and cmaxs are requested, postgres_fdw gives up > pushing down foreign joins. (We might be able to set appropriate values > for them locally the same way as for tableoids, but I'm not sure it's > worth complicating the code.) I think that would be probably OK, > because users wouldn't retrieve any such columns in practice. Now that seems like the wrong reaction. I mean, aren't these just going to be 0 or something? Refusing to push the join down seems strange. -- 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
