From: | Bret Hughes <bhughes(at)elevating(dot)com> |
---|---|
To: | postgresql sql list <pgsql-sql(at)postgresql(dot)org> |
Subject: | Re: group by not returning sorted rows |
Date: | 2004-04-06 16:51:36 |
Message-ID: | 1081270297.18380.142.camel@bretsony |
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Lists: | pgsql-sql |
On Mon, 2004-04-05 at 17:34, Tom Lane wrote:
> Bret Hughes <bhughes(at)elevating(dot)com> writes:
> > and the rows resulting from the query are no longer sorted by log date.
> > Is this a change since 7.2x?
>
> Yes. 7.4 can use hashing instead of sorting to bring grouped rows
> together.
>
> > I can achieve the results I need by adding an order by clause identical
> > to the group by but this seems counter intuitive since the rows have to
> > be ordered anyway.
>
> No they don't; you're making an assumption about the implementation that
> is no longer warranted. The SQL spec doesn't require it either ...
> output ordering is only guaranteed if you specify ORDER BY, per spec.
>
> regards, tom lane
Thanks,
I replied to Tom directly by accident and did not want the list to think
I was ungrateful for the quick reply :)
Bret
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