Re: Vacuum statistics

Hi Alena,
Thank you for reworking vacuum_interrupt_count! I tested v44, and the
counter now increases exactly once per failed VACUUM, including failures
originating in a parallel worker. This part looks good to me.

I found two other issues:
1. Parallel VACUUM appears to double-count worker resource usage.
Worker index usage is reported separately, but is also included in the
leader’s table-level usage. For example, with one parallel worker I
observed:
table.total_blks_read      = 729
sum(index.total_blks_read) = 729
database.db_blks_read      = 1459

The corresponding serial VACUUM didn't show this duplication.

2. The reset functions retain the default EXECUTE privilege for PUBLIC.
After granting a non-superuser USAGE on the extension schema, it could
call all three reset functions and remove the accumulated statistics:
vacuum_statistics_reset()
extvac_reset_entry(oid, oid)
extvac_reset_db_entry(oid)

For comparison, pg_stat_reset* functions are restricted to POSTGRES, and
pg_stat_statements explicitly revokes PUBLIC access to its reset
function. Could the extension similarly restrict these functions?

Regards,

Vlada

On 24.09.2026 18:10, Alena Rybakina wrote:
> Hi Karina,
> Thank you for the review!  v44 is attached.
>
>
> On Wed, Sep 23, 2026 at 8:57 AM Karina Litskevich
> <litskevichkarina(at)gmail(dot)com> wrote:
> > CI is complaining about more than one definition of
> > <table id="extvacuumstatistics-pg-stats-vacuum-indexes-columns">
>
> Fixed, the extra table is removed from 0007.
>
>
> > If you add a new external function in
> > visibilitymap.c, i.e., visibilitymap_clear_rel, you should also
> > add it in the INTERFACE ROUTINES list in the beginning of the file.
>
> Done.
>
>
> > I'd also suggest that the variation of the visibilitymap_clear
> > function taking a Relation should be the main one (and be called
> > visibilitymap_clear), and the variant taking a RelFileLocator
> > should be the additional one for those who don't have a Relation
> > (and be called visibilitymap_clear_no_stats or something). I am
> > not insisting, though.
>
> I left it as is for now.  Master has just changed
> visibilitymap_clear() to take a RelFileLocator, and I didn't want to
> change it back.  I can rename it if others prefer.
>
>
> I also changed one more thing in 0004, after a question from Vlada
> Pogozheskaya <v(dot)pogozheskaya(at)postgrespro(dot)ru>. vacuum_interrupt_count
> is now added to the database stats in pgstat_update_dbstats(), the
> same way as xact_rollback, instead of in AtEOXact_PgStat_Database().
> So nothing is done during transaction abort anymore.
>
> --
> Regards,
> Alena Rybakina
> Yandex