From: | Craig Ringer <craig(at)2ndquadrant(dot)com> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Stephen Frost <sfrost(at)snowman(dot)net>, Josh Berkus <josh(at)agliodbs(dot)com>, Kohei KaiGai <kaigai(at)kaigai(dot)gr(dot)jp>, "ktm(at)rice(dot)edu" <ktm(at)rice(dot)edu>, Alexander Korotkov <aekorotkov(at)gmail(dot)com>, Oleg Bartunov <obartunov(at)gmail(dot)com>, Greg Smith <greg(at)2ndquadrant(dot)com>, PgHacker <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: [v9.4] row level security |
Date: | 2013-11-05 01:46:33 |
Message-ID: | 52784DF9.9040205@2ndquadrant.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
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_jhtWc0fV2Q58NEgcxyTA@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
From | Date | Subject | |
---|---|---|---|
Next Message | Noah Misch | 2013-11-05 03:22:09 | Re: List of "binary-compatible" data types |
Previous Message | Josh Berkus | 2013-11-05 01:23:36 | Re: List of "binary-compatible" data types |