Hi, Alexander!
On Tue, Nov 7, 2023 at 3:00 PM Alexander Lakhin <exclus...@gmail.com> wrote:
>
> 07.11.2023 14:38, Alexander Korotkov wrote:
> > Hi, Alexander.
> >
> > On Tue, Nov 7, 2023 at 1:00 PM Alexander Lakhin <exclus...@gmail.com> wrote:
> >> It looks like the v2 patch doesn't fix the original issue. Maybe I miss
> >> something, but with the patch applied, I see the failure immediately,
> >> though without the patch several iterations are needed to get it.
> >
> > That's a bug in the patch. Thank you for cathing it. It should start
> > calculation from latestCompletedXid + 1, not InvalidTransactionId.
> > Please, check the revised patch.
>
> Thanks for looking at this!
> Unfortunately, I still see the failure with the v3, but not on a first
> iteration:
> ...
> iteration 316
> Error condition in psql-8.log:
> create table vacuum_test as select 42 i;
> vacuum (disable_page_skipping) vacuum_test;
> select * from pg_check_visible('vacuum_test');
> t_ctid
> --------
> (0,1)
> (1 row)
>
> (I've double-checked that the patch is applied and get_strict_xid_horizon()
> is called.)I managed to reproduce this on a Linux VM. This problem should arise because in extension I don't have access to ProcArrayStruct. So, my code is iterating the whole PGPROC's array. I reimplemented the new horizon calculation function in the core with usage of ProcArrayStruct. Now it doesn't fall for me. Please, recheck. ------ Regards, Alexander Korotkov
0001-Fix-false-reports-in-pg_visibility-v4.patch
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