Re: lockup in parallel hash join on dikkop (freebsd 14.0-current)

Hi,

On 2023-01-27 23:18:39 -0500, Tom Lane wrote:
> I also saw it on florican, which is/was an i386 machine using clang and
> pretty standard build options other than
> 'CFLAGS' => '-msse2 -O2',
> so I think this isn't too much about machine architecture or compiler
> flags.

Ah. Florican dropped of the BF status page and I was too lazy to look
deeper. You have a penchant for odd architectures, so it didn't seem too crazy
:)

> Machine speed might matter though. elver is a good deal faster than
> florican was, and dikkop is slower yet. I gather Thomas has seen this
> only once on elver, but I saw it maybe a dozen times over a couple of
> years on florican, and now dikkop has hit it after not so many runs.

Re-reading the old thread, it is interesting that you tried hard to reproduce
it outside of the BF, without success:
https://postgr.es/m/2398828.1646000688%40sss.pgh.pa.us

Such problems are quite annoying. Last time I hit such a case was
https://postgr.es/m/20220325052654.3xpbmntatyofau2w%40alap3.anarazel.de
but I can't see anything like that being the issue here.

Greetings,

Andres Freund