On Mon, Nov 11, 2013 at 12:53 AM, Erik Rijkers <er@xs4all.nl> wrote:
On Fri, November 8, 2013 21:11, Alvaro Herrera wrote: > > Here's a version 7 of the patch, which fixes these bugs and adds > opclasses for a bunch more types (timestamp, timestamptz, date, time, > timetz), courtesy of Martín Marqués. It's also been rebased to apply > cleanly on top of today's master branch. > > I have also added a selectivity function, but I'm not positive that it's > very useful yet. >
> [minmax-7.patch]
The earlier errors are indeed fixed; now, I've been trying with the attached test case but I'm unable to find a query that improves with minmax index use. (it gets used sometimes but speedup is negligable).
Your data set seems to be completely random. I believe that minmax indices would only be expected to be useful when the data is clustered. Perhaps you could try it on a table where it is populated something like i+random()/10*max_i.
