Re: Missing Chunk Error when doing a VACUUM FULL operation - DB Corruption?

There is nothing in pg_prepared_xacts, however, in pg_stat_activity there
are two pglogical processes that have a "backend_start" of "2017-06-17"
when the last time we restarted this server. Both are not waiting and have
null for "state." This might be expected behavior for pglogical.

I did try TRUNCATE before but even as the postgres user, but for some
reason it didn't allow me to truncate because it was a system table.

On Tue, Oct 31, 2017 at 5:56 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Arjun Ranade <ranade(at)nodalexchange(dot)com> writes:
> > Yes, it is still reproducible. When I try to VACUUM FULL right now, I
> get
> > the same error.
>
> > This is postgres 9.4. I am new to gdb, but based on what you said, I
> have
> > the following output:
>
> > Breakpoint 1, 0x0000000000768be0 in errfinish ()
> > (gdb) bt
> > #0 0x0000000000768be0 in errfinish ()
> > #1 0x000000000076998c in elog_finish ()
> > #2 0x0000000000495960 in ?? ()
> > #3 0x0000000000496075 in heap_tuple_fetch_attr ()
> > #4 0x0000000000496572 in toast_insert_or_update ()
> > #5 0x0000000000492ce1 in ?? ()
> > #6 0x0000000000493733 in rewrite_heap_tuple ()
> > #7 0x000000000053ebdf in ?? ()
> > #8 0x000000000053f68e in cluster_rel ()
> > #9 0x0000000000590a1b in ?? ()
> > #10 0x0000000000590f9f in vacuum ()
> > #11 0x000000000068ee77 in standard_ProcessUtility ()
>
> Hm. I suspect what is happening is that VACUUM is trying to copy a tuple
> that you deleted, but which it thinks is still visible to some open
> transaction. Do you have any really old transactions hanging around,
> according to pg_stat_activity or pg_prepared_xacts?
>
> If that is not it, probably truncating pg_statistic instead of just
> doing "delete from pg_statistic" would solve the problem. But we're
> no closer to understanding what was the original source of the issue.
>
> regards, tom lane
>