Re: Introduce XID age and inactive timeout based replication slot invalidation

On Sun, Mar 24, 2024 at 3:05 PM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> On Sun, Mar 24, 2024 at 10:40 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > > For instance, setting last_inactive_time_1 to an invalid value fails
> > > with the following error:
> > >
> > > error running SQL: 'psql:<stdin>:1: ERROR: invalid input syntax for
> > > type timestamp with time zone: "foo"
> > > LINE 1: SELECT last_inactive_time > 'foo'::timestamptz FROM pg_repli...
> > >
> >
> > It would be found at a later point. It would be probably better to
> > verify immediately after the test that fetches the last_inactive_time
> > value.
>
> Agree. I've added a few more checks explicitly to verify the
> last_inactive_time is sane with the following:
>
> qq[SELECT '$last_inactive_time'::timestamptz > to_timestamp(0)
> AND '$last_inactive_time'::timestamptz >
> '$slot_creation_time'::timestamptz;]
>

Such a test looks reasonable but shall we add equal to in the second
part of the test (like '$last_inactive_time'::timestamptz >=
> '$slot_creation_time'::timestamptz;). This is just to be sure that even if the test ran fast enough to give the same time, the test shouldn't fail. I think it won't matter for correctness as well.

--
With Regards,
Amit Kapila.