Re: Vacuum statistics

Hi, all!

On 25.03.2025 09:12, Alena Rybakina wrote:
>
> Hi! I rebased the patches again - PGSTAT_FILE_FORMAT_ID needed to be
> fixed.
>
On 05.02.2025 09:59, Alexander Korotkov wrote:
> What is the point for disabling pgstat_track_vacuum_statistics then?
> I don't see it saves any valuable resources. The original point by
> Masahiko Sawada was growth of data structures in times [1] (and
> corresponding memory consumption especially with large number of
> tables). Now, disabling pgstat_track_vacuum_statistics only saves
> some cycles of pgstat_accumulate_extvac_stats(), and that seems
> insignificant.
>
> I see that we use hash tables with static element size. So, we can't
> save space by dynamically changing entries size on the base of GUC.
> But could we move vacuum statistics to separate hash tables? When GUC
> is disabled, new hash tables could be just empty.
>
> Links
> 1.https://www.postgresql.org/message-id/CAD21AoD66b3u28n%3D73kudgMp5wiGiyYUN9LuC9z2ka6YTru5Gw%40mail.gmail.com
I did a rebase and finished the part with storing statistics separately
from the relation statistics - now it is possible to disable the
collection of statistics for relationsh using gucs and
this allows us to solve the problem with the memory consumed.

For now I have formatted all this as a diff file. The diff file must be
applied after all patches have been applied. While looking at it I
noticed that the code requires significant code refactoring, so I will
do that.

--
Regards,
Alena Rybakina
Postgres Professional