Message-ID: <48cacb3c6e564e83ff67d7925d75488b79d74dba.camel@cybertec.at>
Subject: Re: Query planner instability on large append-only table with heavy
 same-day inserts
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Giriraj Sharma <giriraj.sharma27@gmail.com>, 
	pgsql-general@lists.postgresql.org
Date: Tue, 28 Oct 2025 14:02:17 +0100
In-Reply-To: <CAB5vuUwa3QBFvJKCWY9PYWM8CM+Qk0XSq1R84zMjuBibVW8ccw@mail.gmail.com>
References: 
	<CAB5vuUwa3QBFvJKCWY9PYWM8CM+Qk0XSq1R84zMjuBibVW8ccw@mail.gmail.com>
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On Tue, 2025-10-28 at 12:06 +0530, Giriraj Sharma wrote:
> We are running into query planner instability on an append-only table tha=
t records daily commit information.
> The workload is heavily skewed toward the current day=E2=80=99s data, and=
 query performance deteriorates periodically until we run ANALYZE.

The best approach is to run autoanalyze often enough, either by reducing
autovacuum_analyze_scale_factor for the table or (as you suggested) by
setting the parameter to 0 and using only autovacuum_analyze_threshold.

There is no way to force a certain plan in PostgreSQL, unless you are
using the pg_hint_plan extension.

Yours,
Laurenz Albe