Re: Autovacuum breakage from a734fd5d1

On Mon, Nov 28, 2016 at 10:02 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Sun, Nov 27, 2016 at 5:45 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> So the problem seems to be confirmed to exist, but be of low probability
>> and low consequences, in back branches. I think we only need to fix it in
>> HEAD. The lock acquisition and status recheck that I proposed before
>> should be sufficient.
>
> Thanks for digging into this. I failed to notice while reviewing that
> the way we were printing the message had changed a bit in the new
> code, and I just totally overlooked the existing locking hazards.
> Oops.

Sorry for the late reply.

In order to reproduce the failure I have just inserted a manual
pg_usleep before looping through the list of orphan_oids, and after
dropping manually from another session a couple of orphaned temporary
tables I was able to see the failure. Attached is a proposal of patch.
--
Michael