Hello, At Thu, 16 Apr 2015 12:20:47 +0900, Etsuro Fujita <fujita.ets...@lab.ntt.co.jp> wrote in <552f2a8f.2090...@lab.ntt.co.jp> > On 2015/04/15 3:52, Alvaro Herrera wrote: > >> On 4/14/15 5:49 AM, Etsuro Fujita wrote: > >>> postgres=# create foreign table ft1 (c1 int) server myserver options > >>> (table_name 't1'); > >>> CREATE FOREIGN TABLE > >>> postgres=# create foreign table ft2 (c1 int) server myserver options > >>> (table_name 't2'); > >>> CREATE FOREIGN TABLE > >>> postgres=# alter foreign table ft2 inherit ft1; > >>> ALTER FOREIGN TABLE > >>> postgres=# select * from ft1 for update; > >>> ERROR: could not find junk tableoid1 column > >>> > >>> I think this is a bug. Attached is a patch fixing this issue. > > > I think the real question is whether we're now (I mean after this > > patch) > > emitting useless tableoid columns that we didn't previously have. I > > think the answer is yes, and if so I think we need a smaller comb to > > fix > > the problem. This one seems rather large. > > My answer for that would be *no* because I think tableoid would be > needed for EvalPlanQual checking in more complex SELECT FOR UPDATE on > the inheritance or UPDATE/DELETE involving the inheritance as a source > table. Also, if we allow the FDW to change the behavior of SELECT FOR > UPDATE so as to match the local semantics exactly, which I'm working > on in another thread, I think tableoid would also be needed for the > actual row locking.
Given the parent foreign talbes, surely they need tableoids for such usage. The patch preserves the condition rc->isParent so it newly affects exactly only parent foreign tables for now. Before the parent foreign tables introduced, ROW_MARK_COPY and RTE_RELATION are mutually exclusive so didn't need, or cannot have tableoid. But now it intorduces an rte with ROW_MARK_COPY & RTE_RELATION and there seems no reason for parent tables in any kind not to have tableoid. After such consideration, I came to think that the patch is a reasonable fix, not mere a workaround. Thoughts? regards, -- Kyotaro Horiguchi NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers