Re: Fix assert failure when decoding XLOG_PARAMETER_CHANGE on primary

Hi,

On Wed, Feb 05, 2025 at 10:59:22AM -0800, Masahiko Sawada wrote:
> On Tue, Feb 4, 2025 at 11:48 PM Bertrand Drouvot
> <bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
> > + if (SlotIsLogical(s) && !EnableHotStandby)
> > + ereport(FATAL,
> > + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> > + errmsg("hot standby must be enabled for pre-existing logical replication slots")));
> >
> > On a primary lowering wal_level < logical, we'd get something like:
> >
> > "
> > FATAL: logical replication slot "logical_slot" exists, but "wal_level" < "logical"
> > "
> >
> > What about being close to it, so something like?
> >
> > "
> > FATAL: logical replication slot "logical_slot" exists, but "hot_standby" = "off"
> > "
>
> Looks good, but I'd like to mention that this is required only on
> standbys. So how about the following?
>
> FATAL: logical replication slot "s" exists on the standby, but
> "hot_standby" = "off"
> HINT: Change "hot_standby" to be "on".

Thanks! Looks good and consistent with the existing wording that can be found
in slot.c.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com