[ retrying from the email address I intended to use ]
On Mon, Apr 20, 2020 at 3:42 PM Andres Freund <andres@anarazel.de> wrote:
> I don't think random interspersed uses of CLogTruncationLock are a good
> idea. If you move to only checking visibility after tuple fits into
> [relfrozenxid, nextXid), then you don't need to take any locks here, as
> long as a lock against vacuum is taken (which I think this should do
> anyway).
I think it would be *really* good to avoid ShareUpdateExclusiveLock
here. Running with only AccessShareLock would be a big advantage. I
agree that any use of CLogTruncationLock should not be "random", but I
don't see why the same method we use to make txid_status() safe to
expose to SQL shouldn't also be used here.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
