Re: DISTINCT -> GROUP BY

2008/6/3 David Fetter <david@fetter.org>:
> On Tue, Jun 03, 2008 at 03:36:44PM +0200, Pavel Stehule wrote:
>> Hello David
>>
>> http://www.postgresql.org/docs/faqs.TODO.html
>>
>> Consider using hash buckets to do DISTINCT, rather than sorting This
>> would be beneficial when there are few distinct values. This is
>> already used by GROUP BY.
>
> It's nice to see that this is kinda on the TODO, but it doesn't
> address the question I asked, which is, "how would I get the planner
> to rewrite DISTINCTs as the equivalent GROUP BYs?" :)

you can't to do it :(

Pavel

>
> Any hints?
>
> Cheers,
> David.
> --
> David Fetter <david@fetter.org> http://fetter.org/
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