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

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