Re: group by not returning sorted rows

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