Re: is it possible to make this faster?

["Merlin Moncure" <mmoncure(at)gmail(dot)com>]

On 5/25/06, Bruno Wolff III <bruno(at)wolff(dot)to> wrote:
> On Thu, May 25, 2006 at 16:07:19 -0400,
>   Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
> > been doing a lot of pgsql/mysql performance testing lately, and there
> > is one query that mysql does much better than pgsql...and I see it a
> > lot in normal development:
> >
> > select a,b,max(c) from t group by a,b;
> >

> SELECT DISTINCT ON (a, b) a, b, c FROM t ORDER BY a DESC, b DESC, c DESC;

that is actually slower than group by in my case...am i missing
something? (both essentially resolved to seq_scan)

merlin