From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Michael Paquier <michael@paquier.xyz>
Cc: Fujii Masao <masao.fujii@gmail.com>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: Add "io worker" as backend_type to the pg_stat_activity documentation
Date: Wed, 22 Jul 2026 07:36:14 +0200
Message-ID: <8a9d8030ebf1b3b39cc3bcf277946dc54dec4e50.camel@cybertec.at> (raw)
In-Reply-To: <al_wOWrsHfB65Zbk@paquier.xyz>
References: <5e94c0196084f648ae6a00107125494f5804318a.camel@cybertec.at>
<al8noIYGjD_Lyyi8@paquier.xyz>
<eb735d8aedf16ab2121af6f9b65b3274927afd2d.camel@cybertec.at>
<CAHGQGwEDY0GkP4Tapn+qtaxB6aNtjPzqozRL8_Hf1Sg3B+H+8w@mail.gmail.com>
<4aff5b0f5a1bf3b487d06daec5ed5a287afa7a22.camel@cybertec.at>
<al_wOWrsHfB65Zbk@paquier.xyz>
On Wed, 2026-07-22 at 07:18 +0900, Michael Paquier wrote:
> On Tue, Jul 21, 2026 at 09:04:15PM +0200, Laurenz Albe wrote:
> > You are right. Here is patch v3 with a completed list; I hope I didn't
> > forget anything.
>
> I am counting 23 entries. I don't see anything forgotten on top of my
> mind, and we are indeed missing a lot of new entries.
Great.
> > + <para>
> > + <literal>autovacuum worker</literal>: A background process running
> > + <command>VACUUM</command> or <command>ANALYZE</command> on a single
> > + table.
> > + </para>
>
> Also active when autovacuum = on?
Well, anti-wraparound autovacuum workers can also run if autovacuum = off.
Also, autovacuum workers only indirectly depend on the GUC.
I figured that if I say that the autovacuum launcher depends on the GUC and
launches autovacuum workers, the indirect dependency should be obvious.
> > + <para>
> > + <literal>walreceiver</literal>: The background process that receives
> > + WAL records from a WAL sender, active in streaming replication
> > + standby mode.
> > + </para>
>
> We can only have one of these.
That's why I said "*the* background process".
Or did I miss your point?
> > + </listitem>
> > + <listitem>
> > + <para>
> > + <literal>walsender</literal>: A background process that sends WAL
> > + records to receivers (during streaming replication) or decodes WAL
> > + and sends the decoded information (during logical replication).
> > + </para>
> > + </listitem>
>
> No mention of the max_wal_senders dependency? Perhaps not worth
> mentioning, still..
I don't want to mention all GUCs that have an influence on the processes,
and I feel that my descriptions are already pretty long.
If I mention that dependency, I should also mention that max_connections
limits the number of backends, and so on...
Yours,
Laurenz Albe
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To: pgsql-docs@postgresql.org
Cc: laurenz.albe@cybertec.at, michael@paquier.xyz, masao.fujii@gmail.com, pgsql-docs@lists.postgresql.org
Subject: Re: Add "io worker" as backend_type to the pg_stat_activity documentation
In-Reply-To: <8a9d8030ebf1b3b39cc3bcf277946dc54dec4e50.camel@cybertec.at>
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