Re: VACUUM/ANALYZE Strategy for Low-Activity PostgreSQL 15 Instance

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From: Rich Meyer <rmeyer(at)sevroconsulting(dot)com>
Date: Tuesday, 13 January 2026 at 18:30
To: Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
Cc: Gabriel Guillem Barceló Soteras <gbarcelo(at)parlamentib(dot)es>, Pgsql-admin <pgsql-admin(at)lists(dot)postgresql(dot)org>
Subject: Re: VACUUM/ANALYZE Strategy for Low-Activity PostgreSQL 15 Instance

Hi, sorry about this but I cannot for the life of me unsubscribe from these emails. Can anyone help?

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Rich Meyer
Sevro Consulting
rmeyer(at)sevroconsulting(dot)com<mailto:rmeyer(at)sevroconsulting(dot)com>
732-991-6249

On 2026-01-13 12:26 pm, Laurenz Albe wrote:

On Tue, 2026-01-13 at 08:19 +0000, Gabriel Guillem Barceló Soteras wrote:
We have a healthy PostgreSQL 15 instance (installed from the official Postgres repository)
running on Red Hat 9. It serves several databases for internal SMB applications.
The environment is stable—apps perform well, disk usage is fine, and the system is not
under heavy load.

After integrating PostgreSQL into our monitoring system, I noticed warnings related to VACUUM
and ANALYZE. Some tables have never undergone these maintenance operations, or the last run
was 30–200 days ago. These databases have very few deletions, and many tables show no growth
at all—typical for internal SMB apps.
I know this topic comes up often, but should I schedule a monthly VACUUM + ANALYZE via a cron
or systemd timer, while still keeping autovacuum enabled?

We’re also monitoring table bloat, which is currently under 1%, suggesting that manual
intervention may not be necessary and that autovacuum is doing its job when needed.

I'd call this a false positive warning from the monitoring system, and there is nothing
you have to do except to disable this test. It is perfectly healthy for a table with
few updates and deletes to ve autovacuumed very rarely.

What you should monitor is

a) whether pg_stat_all.tables.n_dead_tup is much more than 0.2 * pg_class.reltuples + 50
(that would indicate that autovacuum doesn't trigger, is too slow or cannot make any
progress owing to long-running transactions)

b) whether age(pg_class.relfrozenxid) exceeds 300 million
(that would indicate a problem with anti-wraparound autovacuum)

Yours,
Laurenz Albe