Re: pgsql: Track last_inactive_time in pg_replication_slots.

On Mon, Mar 25, 2024 at 9:55 PM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Mon, Mar 25, 2024 at 12:12 PM Bertrand Drouvot
> <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
>
> > Would "released_time" sounds better? (at the end this is exactly what it does
> > represent unless for the case where it is restored from disk for which the meaning
> > would still makes sense to me though). It seems to me that released_time does not
> > lead to any expectation then removing any confusion.
>
> Yeah, that's not bad. I mean, I don't agree that released_time doesn't
> lead to any expectation, but what it leads me to expect is that you're
> going to tell me the time at which the slot was released. So if it's
> currently active, then I see NULL, because it's not released; but if
> it's inactive, then I see the time at which it became so.
>
> In the same vein, I think deactivated_at or inactive_since might be
> good names to consider. I think they get at the same thing as
> released_time, but they avoid introducing a completely new word
> (release, as opposed to active/inactive).
>

We have a consensus on inactive_since, so I'll make that change. I
would also like to solicit your opinion on the other slot-level
parameter we are planning to introduce. This new slot-level parameter
will be named as inactive_timeout. This will indicate that once the
slot is inactive for the inactive_timeout period, we will invalidate
the slot. We are also discussing to have this parameter
(inactive_timeout) as GUC [1]. We can have this new parameter both at
the slot level and as well as a GUC, or just one of those.

[1] - https://www.postgresql.org/message-id/20240325195443.GA2923888%40nathanxps13

--
With Regards,
Amit Kapila.