Re: RHEL certified repo provided PostgreSQL Major Version Upgrade.

Sameer Malve <malvesameer@gmail.com> writes:
> We are trying to perform the Major version upgrade on RHEL 8 using
> RHEL-certified repo `rhel-8-for-x86_64-appstream-rpms` from PG 15.6 to PG
> 16.4 using `pg_upgrade` but we are facing the below issue.
> As the binaries are getting upgraded in-place `/usr/bin` hence while
> performing pg_upgrade we are not getting the older binaries.

It's been more than ten years since I was responsible for Red Hat's
packaging of PG, but I think I recall that the solution in place for
pg_upgrade involved a separate postgresql-upgrade RPM containing
previous-version executables, which you were supposed to install
alongside the new version for long enough to perform the upgrade.
Whatever the details were, I'm quite certain the package's README file
contained an explanation of how to do it.  Read that, do not pay
attention to people or chatbots telling you how you'd do it with some
other packaging.

            regards, tom lane