On 5/25/06, Bruno Wolff III <bruno@wolff.to> wrote:
> On Thu, May 25, 2006 at 16:07:19 -0400,
> Merlin Moncure <mmoncure@gmail.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
