Re: [PATCH] Release replication slot on error in SQL-callable slot functions

On Sun, Aug 30, 2026 at 9:40 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Sat, Aug 29, 2026 at 4:42 AM Bharath Rupireddy
> <bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
> >
> > In the replication slot subxact callback, on the abort path, we need
> > to know whether the slot's creation failed. Ephemeral slots already
> > handle that, but only for persistent logical slots. A temporary slot
> > stays RS_TEMPORARY throughout. So there are a few ways to solve this:
> >
> > 1/ Also mark temporary slots as ephemeral initially and transition
> > them to RS_TEMPORARY once creation succeeds. A quick check shows this
> > needs changes in many places.
> > 2/ Introduce a new state to represent a temporary slot still in
> > creation (RS_TEMPORARY_EPHEMERAL or such).
> > 3/ Use a boolean in the ReplicationSlot structure
> > (is_create_in_progress or such), and in the subxact callback, when the
> > slot is temporary and is_create_in_progress is set, drop just that
> > temporary slot and leave the others alone.
> >
> > I prefer option 3,
> >
>
> I would prefer option-1 as we have a similar pre-existing behaviour.
>
> to keep it simple without adding a new state, and
> > because it is back-branch friendly.
> >
>
> BTW, I was thinking this to be improved in HEAD-only as it is a more
> impactful change.

I was thinking the same. Even if we use option-1, an error could still
happen when saving the slot to the disk (in ReplicationSlotSave()),
leaving the slot behind while returning an error to the client. We
might want to address that point too, and it should be only for HEAD.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com