Date: Thu, 17 Jan 2019 11:46:51 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: Mariel Cherkassky <mariel.cherkassky@gmail.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: autovacuum doesnt run on the pg_toast_id table
Message-ID: <20190117174651.GC18438@telsasoft.com>
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On Thu, Jan 17, 2019 at 07:28:52PM +0200, Mariel Cherkassky wrote:
...
> Now, I realized from the autovacuum
> logging, that when autovacuum runs on the original table (A) it doesn't
> necessary run on the toasted table and this is very weird.
...
> Any idea why the autovacuum doesnt vacuum both tables ?

It *does* vacuum both, just not *necessarily*, as you saw.

The toast is a separate table, so it's tracked separately.

Note that:
|If a table parameter value is set and the
|equivalent <literal>toast.</literal> parameter is not, the TOAST table
|will use the table's parameter value.

You could look in pg_stat_all_tables, to see how frequently the toast is being
autovacuumed relative to its table.

Justin