On Wed, 11 Dec 2019 at 02:08, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote:
> On 2019-Dec-10, Tomas Vondra wrote: > > > On Tue, Dec 10, 2019 at 09:42:17AM +0900, Kyotaro Horiguchi wrote: > > > At Tue, 10 Dec 2019 00:44:09 +0100, Tomas Vondra < > tomas.von...@2ndquadrant.com> wrote in > > > > I'm not sure how much xact_start for walsender is useful and we really > > > is not running a statement there. Also autovac launcher starts > > > transaction without a valid statement timestamp perhaps for the same > > > reason. > > > > Maybe, but then maybe we should change it so that we don't report any > > timestamps for such processes. > > Yeah, I think we should to that. Agreed. Don't report a transaction start timestamp at all if we're not in a read/write txn in the walsender, which we should never be when using a historic snapshot. It's not interesting or relevant. Reporting the commit timestamp of the current or last-processed xact would likely just be fonfusing. I'd rather see that in pg_stat_replication if we're going to show it, that way we can label it usefully. -- Craig Ringer http://www.2ndQuadrant.com/ 2ndQuadrant - PostgreSQL Solutions for the Enterprise
