Re: BUG #16722: PG hanging on COPY when table has close to 2^32 toasts in the table.

On Wed, Nov 18, 2020 at 8:27 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> Hi,
>
> On 2020-11-18 11:57:05 +0100, Magnus Hagander wrote:
> > This definitely sounds like something that's worth putting out as a
> > wait event. Even before you start traversing millions of OIDs it might
> > gradually start to show up, and being able to monitor that would
> > definitely be useful.
>
> I don't think this is likely to work well as a wait event. All the index
> traversals etc will do IO, acquire locks, etc, which will overwrite the
> wait event and reset it to nothing once done.

Oh meh. Yeah, I didn't think about the actual implementation of doing it :/

That said, I'd really prefer to see *some* kind of counter that could
get people noticing this a bit earlier, rather than just bugging them
in the logfile once it's gone over a threshold. A statistics counter
maybe, but I guess that'd have to be tracked at a per-table level to
be really useful, which would make it potentially fairly expensive to
keep around...

--
Magnus Hagander
Me: https://www.hagander.net/
Work: https://www.redpill-linpro.com/