On 2020-02-25 08:30, Antonin Houska wrote:
I'm trying to figure out what's specific about RS_EPHEMERAL and RS_TEMPORARY slot kinds. The following comment (see definition of the ReplicationSlotPersistency enumeration) tells when each kind is dropped
The general idea is that an "ephemeral" slot is a future persistent slot that is not completely initialized yet. If there is a crash and you find an ephemeral slot, you can clean it up. The name is perhaps a bit odd, you can think of it as an uninitialized one. A temporary slot is one that behaves like a temporary table: It is removed at the end of a session.
Perhaps the implementation differences are not big or are none, but it's relevant for reporting. For example, the pg_replication_slots view shows which slots are temporary. You wouldn't want to show an ephemeral slot as temporary.
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