Re: add log messages when replication slots become active and inactive (was Re: Is it worth adding ReplicationSlot active_pid to ReplicationSlotPersistentData?)

If I read the code right, this patch emits logs when
pg_logical_slot_get_changes and pg_replication_slot_advance SQL
functions are called.  Is this desirable/useful, for the use case you
stated at start of thread?  I think it is most likely pointless.  If you
get rid of those, then the only acquisitions that would log messages are
those in StartReplication and StartLogicalReplication.  So I wonder if
it would be better to leave the API of ReplicationSlotAcquire() alone,
and instead make StartReplication and StartLogicalReplication
responsible for those messages.

I didn't look at the release-side messages you're adding, but I suppose
it should be symmetrical.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"El hombre nunca sabe de lo que es capaz hasta que lo intenta" (C. Dickens)