Re: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4

On Sat, Aug 21, 2021 at 02:17:26PM -0400, Tom Lane wrote:
> "ldh(at)laurent-hasson(dot)com" <ldh(at)laurent-hasson(dot)com> writes:
> > So you mean that on average, the 4x overhead of exceptions is around what you'd expect?
>
> Doesn't surprise me any, no. Exception recovery has to clean up after
> a wide variety of possible errors, with only minimal assumptions about
> what the system state had been. So it's expensive. More to the point,
> the overhead's been broadly the same for quite some time.
>
> > As for results in general, yes, your numbers look pretty uniform across versions. On my end, comparing V11.2 vs V13.4 shows a much different picture!
>
> I'm baffled why that should be so. I do not think any of the extensions
> you mention add any exception-recovery overhead, especially not in
> sessions that haven't used them.

Laurent, did you install binaries for v13.4 or compile it ?

What about these ?

SHOW shared_preload_libraries;
SHOW session_preload_libraries;
SHOW local_preload_libraries;

Would you try to reproduce the issue with a fresh database:
CREATE DATABASE udftest; ...

Or a fresh instance created with initdb.

As I recall, you're running postgres under a windows VM - I'm not sure if
that's relevant.

--
Justin