On Fri, Jan 14, 2011 at 7:59 PM, Kevin Grittner <kevin.gritt...@wicourts.gov > wrote:
> Tom Lane <t...@sss.pgh.pa.us> wrote: > > > Shaun's example is a bit off > > > As for speed, either one might be faster in a particular > > situation. > > After fixing a mistake in my testing and learning from Tom's example > I generated queries against the OP's test data which produce > identical results, and I'm finding no significant difference between > run times for the two versions. The OP should definitely try both > against the real tables. > > <snip> > -Kevin > After trying both against the real tables DISTINCT ON seems to be about two orders of magnitude faster than the other options. Thanks so much! Nik Everett
