Re: handling TOAST tables in autovacuum

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> The only change of some consideration is that we will need two passes
> over pg_class to get the list of relations to vacuum, instead of one as
> we do currently. The problem is that we first need to fetch the
> (heap relid, toast relid) mapping before attempting to figure out if any
> given TOAST table needs vacuuming. This is because we want to be using
> the main table's pg_autovacuum, and we can't get at that unless we know
> the main relid.

Umm ... is it chiseled in stone someplace that toast tables shouldn't
have their own pg_autovacuum entries? Seems like that might be a
reasonable component of a "whole nine yards" approach.

> Should we display TOAST tables separately in pg_stat_*_tables? (Maybe
> pg_stat_toast_tables?)

+1 for pg_stat_toast_tables, I think. If you separate them out then
there will need to be some kind of smarts to help the user figure out
which main table a toast table belongs to. This would be easy with a
separate view.

regards, tom lane