On Wed, Apr 20, 2022 at 04:40:44PM -0700, David G. Johnston wrote:
> Hackers,
>
> The new cumulative stats subsystem no longer has a "lost under heavy load"
> problem so that parenthetical should go (or at least be modified).
>
> These stats can be reset so some discussion about how the system uses them
> given that possibility seems like it would be good to add here. I'm not sure
> what that should look like though.
>
> 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
Yes, I agree and plan to apply this patch soon.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
Indecision is a decision. Inaction is an action. Mark Batterson