Hi, On 2019-05-23 09:37:50 -0400, Robert Haas wrote: > On Thu, May 23, 2019 at 9:30 AM Sergei Kornilov <s...@zsrv.org> wrote: > > > wal_level is PGC_POSTMASTER. > > > > But primary can be restarted without restart on standby. We require > > wal_level replica or highter (currently only logical) on standby. So online > > change from logical to replica wal_level is possible on standby's > > controlfile. > > That's true, but Amit's scenario involved a change in wal_level during > the execution of pg_create_logical_replication_slot(), which I think > can't happen.
I don't see why not - we're talking about the wal_level in the WAL stream, not the setting on the standby. And that can change during the execution of pg_create_logical_replication_slot(), if a PARAMTER_CHANGE record is replayed. I don't think it's actually a problem, as I outlined in my response to Amit, though. Greetings, Andres Freund
