On 10/31/22 13:37, Joshua Drake wrote:
> Team,
>
> While on the road in Iowa visiting covered bridges I met up with an
> amazing individual named Brent. Brent, is with a small organization
> named: Darpa.
>
> They are using PostgreSQL + RLS + XPATH but unfortunately the
> performance has been less than what those who use PostgreSQL on a daily
> basis would expect. Specifically when using RLS + XPATH, the optimizer
> does not prefilter and will scan every row. This has taken their
> previous queries on another database from sub second, to 25+ seconds on
> PostgreSQL.
>
> Unfortunately, we were at a covered bridge park (see attached) and
> weren't able to get deeper into the issue. That said, I did tell him
> that I would report the issue. Maybe there is traction, maybe there
> isn't to get this issue fixed.
The related functions need to be marked leakproof to get decent
performance from RLS.
--
Joe Conway
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
