Re: Single transaction in the tablesync worker?

On Wed, Feb 3, 2021 at 2:51 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> On Wed, Feb 3, 2021 at 1:34 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Wed, Feb 3, 2021 at 6:38 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> > >
> > > On Wed, Feb 3, 2021 at 12:26 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > > >
> > > > On Tue, Feb 2, 2021 at 3:31 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> > > > >
> > > > > After seeing Ajin's test [ac0202] which did a DROP TABLE, I have also
> > > > > tried a simple test where I do a DROP TABLE with very bad timing for
> > > > > the tablesync worker. It seems that doing this can cause the sync
> > > > > worker's MyLogicalRepWorker->relid to become invalid.
> > > > >
> > > >
> > > > I think this should be fixed by latest patch because I have disallowed
> > > > drop of a table when its synchronization is in progress. You can check
> > > > once and let me know if the issue still exists?
> > > >
> > >
> > > FYI - I confirmed that the problem scenario that I reported yesterday
> > > is no longer possible because now the V25 patch is disallowing the
> > > DROP TABLE while the tablesync is still running.
> > >
> >
> > Thanks for the confirmation. BTW, can you please check if we can
> > reproduce that problem without this patch? If so, we might want to
> > apply this fix irrespective of this patch. If not, why not?
> >
>
> Yes, this was an existing postgres bug. It is independent of the patch.
>
> I can reproduce exactly the same stacktrace using the HEAD src pulled @ 3/Feb.
>
> PSA my test logs showing the details.
>

Since this is an existing PG bug independent of this patch, I spawned
a new thread [ps0202] to deal with this problem.

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[ps0202] https://www.postgresql.org/message-id/CAHut%2BPu7Z4a%3Domo%2BTvK5Gub2hxcJ7-3%2BBu1FO_%2B%2BfpFTW0oQfQ%40mail.gmail.com

Kind Regards,
Peter Smith.
Fujitsu Australia