Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM - Mailing list pgsql-bugs

From Cherio
Subject Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM
Date
Msg-id CAKHqFkL3Ms6NzZ9_9UbpN3Qr0UKHdHisRH=JkeGYirYRhg0R7g@mail.gmail.com
Whole thread Raw
In response to Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-bugs
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@sss.pgh.pa.us> wrote:
Cherio <cherio@gmail.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

pgsql-bugs by date:

Previous
From: Tom Lane
Date:
Subject: Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM
Next
From: Tom Lane
Date:
Subject: Re: BUG #17810: Update from 13.09 to 13.10 breaks SQLs with VACUUM