Re: wrong query results on bf leafhopper

On 5/20/25 07:50, David Rowley wrote:
> On Tue, 20 May 2025 at 16:07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Failures like this one [1]:
>>
>> @@ -340,9 +340,13 @@
>> create function myinthash(myint) returns integer strict immutable language
>> internal as 'hashint4';
>> NOTICE: argument type myint is only a shell
>> +ERROR: ROWS is not applicable when function does not return a set
>>
>> are hard to explain as anything besides "that machine is quite
>> broken". Whether it's flaky hardware, broken compiler, or what is
>> undeterminable from here, but I don't believe it's our bug. So I'm
>> unexcited about putting effort into it.
>
> There are certainly much fewer moving parts in PostgreSQL code for
> that one as this failure doesn't seem to rely on anything stored in
> any tables or the catalogues.
>
> I'd have thought it would be unlikely to be a compiler bug as wouldn't
> that mean it'd fail every time?
>
> Are there any Prime95-like stress testers for ARM that could be run on
> this machine?
>
> It would be good to kick this one out the pool if there's hardware issues.
>

There are tools like "stress" and "stressant", etc. Works on my rpi5,
but depends on the packager.

I'd probably just look at dmesg first. In my experience hardware issues
are often pretty visible there - reports of failed I/O requests, thermal
issues on the CPU, that kind of stuff.

regards

--
Tomas Vondra