Re: Add index scan progress to pg_stat_progress_vacuum

On Fri, Jan 6, 2023 at 12:07 PM Imseih (AWS), Sami <simseih(at)amazon(dot)com> wrote:
>
> > Similar to above three cases, vacuum can bypass index vacuuming if
> > there are almost zero TIDs. Should we set indexes_total to 0 in this
> > case too? If so, I think we can set both indexes_total and
> > indexes_completed at the beginning of the index vacuuming/cleanup and
> > reset them at the end.
>
> Unlike the other 3 cases, in which the vacuum and cleanup are totally skipped,
> a cleanup still occurs when the index vacuum is bypassed. From what I can tell,
> this is to allow for things like a gin pending list cleanup even if the index
> is not vacuumed.

Right. But since we set indexes_total also at the beginning of index
cleanup (i.e. lazy_cleanup_all_indexes()), can't we still show the
valid value in this case? My point is whether we should show
indexes_total throughout the vacuum execution (even also in not
relevant phases such as heap scanning/vacuum/truncation). For example,
in the analyze progress report, we have child_tables_total and
child_tables_done. child_tables_total is set before the actual work of
sampling rows from child tables, but not the beginning of the analyze.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com