Re: regarding statistics retaining with 18 Upgrade - Mailing list pgsql-hackers

On Sun, Nov 16, 2025 at 5:22 AM Robert Treat <rob@xzilla.net> wrote:
>
> On Sat, Nov 15, 2025 at 9:32 AM Bruce Momjian <bruce@momjian.us> wrote:
> > On Sat, Nov 15, 2025 at 06:02:53PM +0800, Rambabu V wrote:
> > > Hi Team,
> > >
> > > seems stats are not retained after upgrade. Below are the artifacts , is it
> > > expected? as per the release notes statistics should be retained.
> >
> > Uh, it is the _optimizer_ statistics that are preserved by pg_upgrade,
> > not the cumulative statistics system:
> >
> >         https://www.postgresql.org/docs/current/monitoring-stats.html
> >
> > Yes, they are easily confused.
> >
>
> I wonder if it might be worth trying to clarify this a little bit
> more... perhaps something like the attached?

IMHO it makes sense to update the doc as you suggested to avoid any confusion.

--
Regards,
Dilip Kumar
Google