On 11/04/2013 11:17 PM, Robert Haas wrote: > I'd still like to here what's wrong with what I said here: > > http://www.postgresql.org/message-id/ca+tgmoyr1phw3x9vnvuwdcfxkzk2p_jhtwc0fv2q58negcx...@mail.gmail.com
For me, just my understanding. I'm still too new to the planner and rewriter to grasp that properly as written. I was responding to Tom's objection, and he makes a good point about CASE and optimisation. We have to be free to re-order and pre-evaluate where LEAKPROOF flags make it safe and permissible, without ever otherwise doing so. That makes the SECURITY BARRIER subquery look better, since the limited pull-up / push-down is already implemented there. Robert, any suggesitons on how to approach what you suggest? I'm pretty new to the planner's guts, but I know there've been some complaints about the way the current RLS code fiddles with Vars when it changes a direct scan of a rel into a subquery scan. The code in: https://github.com/ringerc/postgres/blob/rls-9.4/src/backend/optimizer/prep/prepunion.c#L1647 and https://github.com/ringerc/postgres/blob/rls-9.4/src/backend/optimizer/prep/prepunion.c#L1591 seems to be the one folks were complaining about earlier. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
