On Fri, Oct 4, 2013 at 5:04 AM, Marko Tiikkaja <ma...@joh.to> wrote: > I might be completely in the woods here, but I believe something like this > was attempted by Karol earlier, and it failed if two concurrent transactions > did something similar to: > > UPDATE foo SET a = a + 1 RETURNING BEFORE.a; > > Both of them would see BEFORE.a = 0, because that's what the "a" evaluated > to from the tuple we got before EvalPlanQual. > > But maybe what you're suggesting doesn't have this problem?
Hmm, it probably does. That explains why there are executor changes here; I guess they need some comments to explain their purpose. -- 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
