On 2015/03/25 4:56, Tom Lane wrote: > Etsuro Fujita <fujita.ets...@lab.ntt.co.jp> writes: >> Let me explain further. Here is the comment in ExecOpenScanRelation: > >> * Determine the lock type we need. First, scan to see if target >> relation >> * is a result relation. If not, check if it's a FOR UPDATE/FOR SHARE >> * relation. In either of those cases, we got the lock already. > >> I think this is not true for foreign tables selected FOR UPDATE/SHARE, >> which have markType = ROW_MARK_COPY, because such foreign tables don't >> get opened/locked by InitPlan. Then such foreign tables don't get >> locked by neither of InitPlan nor ExecOpenScanRelation. I think this is >> a bug. > > You are right. I think it may not matter in practice, but if the executor > is taking its own locks here then it should not overlook ROW_MARK_COPY > cases. > >> To fix it, I think we should open/lock such foreign tables at >> InitPlan as the original patch does. > > I still don't like that; InitPlan is not doing something that would > require physical table access. The right thing is to fix > ExecOpenScanRelation's idea of whether InitPlan took a lock or not, > which I've now done.
OK, thanks. Best regards, Etsuro Fujita -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
