Re: Vacuum statistics

On 10.8.24 22:37, Andrei Zubkov wrote:

> Hi, Ilia!
>
>> Do you consider not to create new table in pg_catalog but to save
>> statistics in existing table? I mean pg_class or
>> pg_stat_progress_analyze, pg_stat_progress_vacuum?
>>
> Thank you for your interest on our patch!
>
> *_progress views is not our case. They hold online statistics while
> vacuum is in progress. Once work is done on a table the entry is gone
> from those views. Idea of this patch is the opposite - it doesn't
> provide online statistics but it accumulates statistics about rosources
> consumed by all vacuum passes over all relations. It's much closer to
> the pg_stat_all_tables than pg_stat_progress_vacuum.
>
> It seems pg_class is not the right place because it is not a statistic
> view - it holds the current relation state and haven't anything about
> the relation workload.
>
> Maybe the pg_stat_all_tables is the right place but I have several
> thoughts about why it is not:
> - Some statistics provided by this patch is really vacuum specific. I
> don't think we want them in the relation statistics view.
> - Postgres is extreamly extensible. I'm sure someday there will be
> table AMs that does not need the vacuum at all.
>
> Right now vacuum specific workload views seems optimal choice to me.
>
> Regards,

Agreed. They are not god places to store such statistics.

I have some suggestions:

1. pgstatfuncs.c in functions tuplestore_put_for_database() and
tuplestore_put_for_relation you can remove 'nulls' array if you're
sure that columns cannot be NULL.
2. These functions are almost the same and I would think of writing one
function depending of type 'ExtVacReportType'