Re: [HACKERS] DISTINCT -> GROUP BY

On Jun 3, 2008, at 9:03 AM, David Fetter wrote: 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.

Re: [HACKERS] DISTINCT -> GROUP BY

2008/6/3 David Fetter <[EMAIL PROTECTED]>: > 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 distinc

Re: [HACKERS] DISTINCT -> GROUP BY

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

Re: [HACKERS] DISTINCT -> GROUP BY

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. Regards Pavel Stehule 2008/6/3 David Fetter <[EMAIL PROTECTED]>: > Folks, > >

[HACKERS] DISTINCT -> GROUP BY

Folks, I've noticed that queries of the form SELECT DISTNCT foo, bar, baz FROM quux WHERE ... perform significantly worse than the equivalent using GROUP BY. SELECT foo, bar, baz FROM quux WHERE ... GROUP BY foo, bar, baz Where would I start looking in order to make them actually equivalent fr