Re: Help optimizing a slow index scan

On Fri, Mar 17, 2006 at 08:34:26 -0700,
  Dan Harris <fbsd@drivefaster.net> wrote:
> Markus Bertheau wrote:
> >Have you tried using a GIST index on lat & long? These things are
> >meant for two-dimensional data, whereas btree doesn't handle
> >two-dimensional data that well. How many rows satisfy either of the
> >long / lat condition?
> >
> >
> >>
> According to the analyze, less than 500 rows matched.  I'll look into
> GIST indexes, thanks for the feedback.

Have you looked at using the Earth Distance contrib module? If a spherical
model of the earth is suitable for your application, then it may work for you
and might be easier than trying to create Gist indexes yourself.