Re: [PATCH] Add max_logical_replication_slots GUC

On Thu, Jan 29, 2026, at 8:33 AM, Ahmed Et-tanany wrote:
>
> I find the idea of a reserved_replication_slots parameter
> interesting. However, I'm thinking about the amount of additional
> semantics we'd need to introduce to properly manage slot ownership,
> since we currently don't have the concept of a role specifically
> reserving or owning a replication slot.
>

If the role credentials are valid and the role has REPLICATION privilege, it
can use any replication slots. The proposal is an extra requirement to allow
the role to use a reserved pool of replication slots. I don't think the
resource (replication slot) needs ownership and privileges for a fine-grained
control.

> It seems to me we'd either keep it simple and focus on just limiting
> the number of logical slots, or explore the role-based reservation
> idea more in-depth.
>

As Fujii said I'm afraid we also need another GUC (for WAL senders) since X
active replication slots implies at least X walsenders. In order to guarantee
there won't be physical replication interruption, you also need to guarantee
that there will be a walsender available.

--
Euler Taveira
EDB https://www.enterprisedb.com/