Thread

Re: LISTEN/NOTIFY bug: VACUUM sets frozenxid past a xid in async queue

Joel Jacobson <joel@compiler.org> — 2025-10-30T23:27:11Z

On Fri, Oct 31, 2025, at 00:08, Joel Jacobson wrote:
> On Thu, Oct 30, 2025, at 14:25, Heikki Linnakangas wrote:
>> Joel, since you've been working on some optimizations in this area too, 
>> would you happen to have some suitable performance test scripts for this?
>
> Glad you asked. I'm actually working on a benchmark+correctness tester.
> It's very much work-in-progress though, don't look too much at the code,
> or your eyes will bleed.
>
> It's a combined benchmark + correctness tester, that verifies that only
> the expected notifications are received on the expected connections,
> while at the same time doing timing measurements.

To run multiple pg_bench_lino processes in parallell to simulate
concurrent workloads, I realized the randomization of the channel names
and payloads were not random enough to avoid collissions. New version
attached that uses real UUIDs for channel names and payloads.

/Joel