Re: BUG #17212: pg_amcheck fails on checking temporary relations

On Mon, Oct 11, 2021 at 11:12 AM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> Sure, the user might not be happy with --parent-check throwing an
> error on a replica. But in practice most users won't want to do that
> anyway. Even on a primary it's usually not possible as a practical
> matter, because the locking implications are *bad* -- it's just too
> disruptive, for too little extra coverage. And so when --parent-check
> fails on a replica, it really is very likely that the user should just
> not do that. Which is easy: just remove --parent-check, and try again.

We should have a warning box about this in the pg_amcheck docs. Users
should think carefully about ever using --parent-check, since it alone
totally changes the locking requirements (actually --rootdescend will
do that too, but only because that option also implies
--parent-check).

--
Peter Geoghegan