Re: Determine if postgresql cluster running is primary or not

On Friday, November 20, 2020, Paul Förster <paul(dot)foerster(at)gmail(dot)com> wrote:

> Hi David,
>
> > On 20. Nov, 2020, at 10:34, David G. Johnston <
> david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
> >
> >
> > On Friday, November 20, 2020, Paul Förster <paul(dot)foerster(at)gmail(dot)com>
> wrote:
> >
> > > On 20. Nov, 2020, at 10:03, Thomas Kellerer <shammat(at)gmx(dot)net> wrote:
> >
> > >
> > > select pg_is_in_recovery();
> >
> > I usually don't recommend using pg_is_in_recovery() only because a
> database cluster can be in recovery for other reasons. This is why I always
> do the following:
> >
> > Do any of those other reasons allow connections that could execute that
> function to exist?
>
> that always depends on what your application does. An application could
> still select a lot of things, maybe even wrongly so, even if the cluster is
> in recovery mode.

I don’t follow - i posit that if psql successfully connects to a server
that reports it is is recovery that server is a secondary to some other
server, period. Can you provide a counter-example for when that isn’t true
(given the whole psql connects successfully bit).

David J.