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Re: Add pg_stat_autovacuum_priority

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

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From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
To: Sami Imseih <samimseih@gmail.com>
Cc: satyanarlapuram@gmail.com, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2026-03-30T02:09:03Z
Lists: pgsql-hackers 
Hi,

On Sat, Mar 28, 2026 at 10:54 AM Sami Imseih <samimseih@gmail.com> wrote:
>
> > 4. Is the view intended to be exposed to PUBLIC without any ACL restrictions?
>
> > 2/ Do we need to revoke permissions on pg_stat_get_autovacuum_priority
> > for all and grant them to pg_monitor or similar? Especially since this
> > function loops over all the relations in a database, we may not want
> > everyone to be able to do this.
>
> I think you're correct there. While the data is not sensitive, it
> should have more controlled usage. It's only taking an AccessShareLock,
> but you would not want anyone to be able to run this since it's
> doing real computation. I think requiring pg_read_all_stats
> is a good idea. Will do.

+1 for pg_read_all_stats.

> > Can we have the per-relation prioritization computation function in C
> > and provide a per-database computation function as a SQL function over
> > this per-relation function in system_functions.sql?
>
> Yes, perhaps we should do this. So we can have a function called
> pg_stat_get_autovacuum_priority() that either takes a NULL or an OID
> to either return all the tables or just a single table.
> This is a similar usage pattern as pg_stat_get_subscription or
> pg_stat_get_activity.
>
> pg_stat_autovacuum_priority will be a view that wraps around the NULL
> variant of the function.
>
> The case where the OID is passed we just do a SearchSysCache1(RELOID,...)
> whereas the other case will do the full catalog scan.
>
> What do you think?

IMHO, we can have pg_stat_get_relation_autovacuum_priority defined as
a C function to give the autovacuum scoring as of the given moment for
the given table. It's easy for one to write a function to get scoring
for all the relations in a database. This keeps things simple yet
useful.

--
Bharath Rupireddy
Amazon Web Services: https://aws.amazon.com

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix double-free in pg_stat_autovacuum_scores.

  2. Add LOG_NEVER error level code.

  3. Add pg_stat_autovacuum_scores system view.

  4. Remove recheck_relation_needs_vacanalyze().

  5. Add elevel parameter to relation_needs_vacanalyze().

  6. Teach relation_needs_vacanalyze() to always compute scores.

  7. Refactor relation_needs_vacanalyze().

  8. Add rudimentary table prioritization to autovacuum.

  9. Fix per-relation memory leakage in autovacuum.

  10. Fix recently-understood problems with handling of XID freezing, particularly