Re: doc: New cumulative stats subsystem obsoletes comment in maintenance.sgml

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com>
Cc: Andres Freund <andres(at)anarazel(dot)de>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: doc: New cumulative stats subsystem obsoletes comment in maintenance.sgml
Date: 2023-10-28 01:23:29
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On Fri, Aug 12, 2022 at 12:58:28PM -0700, David G. Johnston wrote:
> I dislike using the word accurate here now, it will be accurate, but we don't
> promise perfect timeliness.  So it needs to change:
>  diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
> index 04a04e0e5f..360807c8f9 100644
> --- a/doc/src/sgml/maintenance.sgml
> +++ b/doc/src/sgml/maintenance.sgml
> @@ -652,9 +652,8 @@ vacuum insert threshold = vacuum base insert threshold +
> vacuum insert scale fac
>      tuples to be frozen by earlier vacuums.  The number of obsolete tuples and
>      the number of inserted tuples are obtained from the cumulative statistics
> system;
>      it is a semi-accurate count updated by each <command>UPDATE</command>,
> -    <command>DELETE</command> and <command>INSERT</command> operation.  (It is
> -    only semi-accurate because some information might be lost under heavy
> -    load.)  If the <structfield>relfrozenxid</structfield> value of the table
> +    <command>DELETE</command> and <command>INSERT</command> operation.
> +    If the <structfield>relfrozenxid</structfield> value of the table
>      is more than <varname>vacuum_freeze_table_age</varname> transactions old,
>      an aggressive vacuum is performed to freeze old tuples and advance
>      <structfield>relfrozenxid</structfield>; otherwise, only pages that have
> been modified

Done in master.

> However, also replace the remaining instance of "a semi-accurate count" with
> "an eventually-consistent count".

> is an eventually-consistent count updated by each UPDATE, DELETE, and
> INSERT operation.

Also done.

Bruce Momjian <bruce(at)momjian(dot)us>

Only you can decide what is important to you.

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