Re: Add index scan progress to pg_stat_progress_vacuum

> Can the leader pass a callback that checks PVIndStats to ambulkdelete
> an amvacuumcleanup callbacks? I think that in the passed callback, the
> leader checks if the number of processed indexes and updates its
> progress information if the current progress needs to be updated.

Thanks for the suggestion.

I looked at this option a but today and found that passing the callback
will also require signature changes to the ambulkdelete and
amvacuumcleanup routines.

This will also require us to check after x pages have been
scanned inside vacuumscan and vacuumcleanup. After x pages
the callback can then update the leaders progress.
I am not sure if adding additional complexity to the scan/cleanup path
is justified for what this patch is attempting to do.

There will also be a lag of the leader updating the progress as it
must scan x amount of pages before updating. Obviously, the more
Pages to the scan, the longer the lag will be.

Would like to hear your thoughts on the above.

Regards,

Sami Imseih
Amazon Web Services.