Re: find replication slots that "belong" to a publication

On Mon, 2025-04-07 at 12:16 +0200, Willy-Bas Loos wrote:
> My question is not so much about "can i drop a certain replication slot", 
> more about "does this publication still have any replication slots?".
> Or, if you will: "what's the publication for this replication slot?".
>
> I've double checked the views that you suggested, and I found that I can relate
> the WAL sender processes to replication slots through pg_replication_slots.active_pid .
> I've also looked into replication origins.
>
> But I can't find a link to the publication. And that's what I need to know.

I don't think that there is a connection between a publication and a
replication slot.  That connection is only made when a subscriber connects
and runs the START_REPLICATION command [1] and specifies the "pgoutput"
plugin with the "publication_names" option [2].

I don't think you can see that information reflected in a system view
on the primary.  You'd have to query "pg_subscription" on the standby.

Yours,
Laurenz Albe


 [1]:
https://www.postgresql.org/docs/current/protocol-replication.html#PROTOCOL-REPLICATION-START-REPLICATION-SLOT-LOGICAL
 [2]: https://www.postgresql.org/docs/current/protocol-logical-replication.html#PROTOCOL-LOGICAL-REPLICATION-PARAMS