On Wed, Feb 7, 2018 at 8:52 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>> Waiting as you say would be akin to what the patch does by putting
>> vacuum on its own parallel group.
>
> I don't think it's the same. We don't need to wait until all the
> concurrent tests are done -- we only need to wait until the transactions
> that were current when the delete finished are done, which is very
> different since each test runs tons of small transactions rather than
> one single big transaction.
Um... maybe "lock pg_class" ?
That should conflict with basically any other running transaction and
have pretty much that effect.
Attached is a version of patch 1 with that approach.