Re: Upgrade from Fedora 40 to Fedora 42, or from PostgreSQL 16.3 to PostgreSQL 16.9

On Fri, Jul 18, 2025 at 4:09 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> "Michael J. Baars" <mjbaars1977.pgsql@gmail.com> writes:
> > Somewhere in between release 16.3 and
> > release 16.9, changes must have been implemented that make the execution
> > engine about two times slower than it was.
>
> That seems quite unlikely, and you've surely provided no details that
> would help identify any such problem.  My own first guess is that the
> newer install was somehow built with debugging assertions enabled
> (configure's --enable-cassert option).  Those are pretty heavyweight
> and could possibly account for this.  A second guess is that you were
> relying on JIT compilation and the newer install somehow omitted that
> (failed to use --with-llvm).  Anyway, I'd start by comparing the
> output of pg_config from both installs.
>
>                         regards, tom lane

Compiling from source with a default ./configure --prefix=/usr/local
solves the problem.

Thank you for your help!

Mischa.