Re: BUG #18909: Query creates millions of temporary files and stalls

On Sat, 2025-05-03 at 12:27 -0400, Tom Lane wrote:
> Sergey Koposov <Sergey(dot)Koposov(at)ed(dot)ac(dot)uk> writes:
> > #8 0x00005615d84f6a59 in ExecHashTableInsert (hashtable=0x5615da85e5c0, slot=0x5615da823378, hashvalue=2415356794)
> > at nodeHash.c:1714
> > shouldFree = true
> > tuple = 0x5615da85f5e8
> > bucketno = 32992122
> > batchno = 3521863
>
> Yeah, this confirms the idea that the hashtable has exploded into an
> unreasonable number of buckets and batches. I don't know why a
> parallel hash join would be more prone to do that than a non-parallel
> one, though. I'm hoping some of the folks who worked on PHJ will
> look at this.
>

Thanks

> What have you got work_mem set to? I hope it's fairly large, if
> you need to join such large tables.
>

Here're my memory settings

shared_buffers = 32GB
work_mem = 1GB

S

The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. Is e buidheann carthannais a th’ ann an Oilthigh Dhùn Èideann, clàraichte an Alba, àireamh clàraidh SC005336.