From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Okulovich <aokulovich@stiltsoft.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Postgres 15 SELECT query doesn't use index under RLS
Date: Thu, 26 Oct 2023 10:09:37 -0400
Message-ID: <1157086.1698329377@sss.pgh.pa.us> (raw)
In-Reply-To: <e9d503cb-efeb-43d3-952e-f517e4d24302@stiltsoft.com>
References: <5c1179bb-240b-4c1c-b4b3-2a24868e44bc@stiltsoft.com>
<1570249.1697228785@sss.pgh.pa.us>
<dd874d42-ad02-48a6-82db-5666f1ee0ec1@stiltsoft.com>
<3153246.1697661350@sss.pgh.pa.us>
<e9d503cb-efeb-43d3-952e-f517e4d24302@stiltsoft.com>
Alexander Okulovich <aokulovich@stiltsoft.com> writes:
> I've attempted to reproduce this on my PC in Docker from the stage
> database dump, but no luck. The first query execution on Postgres 15
> behaves like on the real stage, but subsequent ones use the index.
Can you force it in either direction with "set enable_seqscan = off"
(resp. "set enable_indexscan = off")? If so, how do the estimated
costs compare for the two plan shapes?
> Also,
> they execute much faster. Looks like the hardware and(or) the data
> structure on disk matters.
Maybe your prod installation has a bloated index, and that's driving
up the estimated cost enough to steer the planner away from it.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, aokulovich@stiltsoft.com
Subject: Re: Postgres 15 SELECT query doesn't use index under RLS
In-Reply-To: <1157086.1698329377@sss.pgh.pa.us>
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