Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM

The second script should have tables used in the reversed order:

UPDATE tableA
UPDATE tableB

and

UPDATE tableB
UPDATE tableA

Since they will run in individual transactions tableA gets locked by the
1st script and tableB by the 2nd; as execution flow proceeds to the next
update in each script, those tables would be locked in separate
transactions.

On Mon, Feb 27, 2023 at 1:00 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Cherio <cherio(at)gmail(dot)com> writes:
> > I just realized that the ramifications of this change go further than
> just
> > VACUUM related statements in the scripts. Assume 2 scripts
>
> > UPDATE tableA
> > UPDATE tableB
>
> > and
>
> > UPDATE tableA
> > UPDATE tableB
>
> > Before the change they could run in parallel without issues. After the
> > change this will cause one of the queries to fail due to transaction
> locks.
>
> Uh ... really? Please provide evidence. AFAIK this set of changes
> only affects commands that are meant to not run inside tranaction blocks.
>
> regards, tom lane
>