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)