Horton

Re: BUG #17172: NaN compare error in hash agg

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: ma100@hotmail.com
Cc: pgsql-bugs@lists.postgresql.org
Date: 2021-09-02T21:28:04Z
Lists: pgsql-bugs 
I wrote:
> This has been broken for a very long time.  Do we dare back-patch
> the fix?  Given the lack of complaints, maybe fixing it in HEAD/v14
> is enough.  OTOH, it's not likely that many people have hash indexes
> containing minus NaNs, so maybe it's okay to back-patch.

After further thought I concluded that there's little reason
not to back-patch.  If someone has -NaN in a hash index,
they'd need to re-index if they ever want to find that entry
again ... but it was already true that many queries would not
find that entry.  Hence, pushed to all branches.

			regards, tom lane

Commits

  1. Fix float4/float8 hash functions to produce uniform results for NaNs.