Re: upgrade from 13 to 16

Am 02.03.26 um 15:31 schrieb Ron Johnson:
> On Mon, Mar 2, 2026 at 9:09 AM listy <listy(at)localities(dot)work> wrote:
>
> Cannot say about Debian but RHEL family (perhaps exceptions exist)
> do not, certainly not on Centos, Ubuntu which I use, yes.
> But also rhel/centos do not do major PGsql rel. upgrade within the
> same/one OS release, I do not think so.
> What happened to me - what I did rather - was upgrade from c9 to
> c10. (not officially supported.)
>
>
> This is why I strongly urge you to use the PGDG repositories, not the
> packages which RHEL builds.
>
> --
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!

Yes, RHEL doesn't take into account that PostgreSQL will ever be
upgraded to another major version. They support the version which was
current when they had their feature freeze for the lifetime of the system.

Therefore Ron is perfectly correct in writing that everybody should use
the PGDG from the beginning.

You might have success installing the new version from PGDG repos and
then run pg_upgrade (with all 4 mentioned options) from the new version.
The preconditions for pg_upgrade are:

* you have the old and the new software version installed (pg-13 and
pg-18) in different directories
* you have the old cluster unchanged and an empty new cluster in
different directories

Maybe it helps to move the data directory of the old cluster before
installing the new software package. Make sure you also change the path
in the systemd service unit of the old version.

If the database isn't large, dump & restore will also work fine.

Regards,

Holger

--

Holger Jakobs, Bergisch Gladbach, Germany