From: | Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> |
---|---|
To: | darrenk(at)insightdist(dot)com (Darren King) |
Cc: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: [HACKERS] No: implied sort with group by |
Date: | 1998-01-29 14:51:04 |
Message-ID: | 199801291451.JAA10489@candle.pha.pa.us |
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Lists: | pgsql-hackers |
> > And in v6.1. If b is a space (rather than a NULL), then the behaviour is correct
> > so it must be a problem in grouping NULLs.
> >
>
> explain select b,c,sum(a) from foo group by b,c; -- gives...
>
> Aggregate (cost=0.00 size=0 width=0)
> -> Group (cost=0.00 size=0 width=0)
> -> Sort (cost=0.00 size=0 width=0)
> -> Seq Scan on foo (cost=0.00 size=0 width=28)
>
> There sort is there before the grouping operation, so this would seem to point to
> the sort code incorrectly setting something when handling NULLs.
>
> This doesn't seem like the same bug that Vadim found since a small data set such as
> this one _shouldn't_ be going out to a tape file.
We have a NULL sort patch for psort in 6.3. Are you running the most
recent sources?
--
Bruce Momjian
maillist(at)candle(dot)pha(dot)pa(dot)us
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