On Thu, 2023-05-18 at 17:34 +0100, Owen Stephens wrote: > We are seeing that vacuum is prevented from cleaning dead tuples by an open > transaction in a different database (where both connections are made against > the > primary server) when hot_standby_feedback = on but not when it is off. Is this > cross-database interaction an expected effect of enabling > hot_standby_feedback, > even if the connections interact only with the primary not the replica?
Yes, that's what I would expect. There is only one "backend_xmin" in "pg_stat_replication", which corresponds to the snapshot held by the oldest query in any database on the standby server. Yours, Laurenz Albe