Re: point types in "DISTINCT" queries

On Tue, 2011-06-28 at 18:56 -0400, Jonathan S. Katz wrote:

> I looked into the mailing list archives and found a potential answer
> on this thread:
> http://archives.postgresql.org/pgsql-general/2009-10/msg01122.php
> However I wanted to see if it was still necessary that I would need
> the complete btree operator class to run such a query.

Yes, the default btree operator class is used to find the equality
operator. Even though you have defined the operator "=", postgresql
doesn't rely on that meaning "equals" -- the btree operator class is
what imparts that meaning.

> Are there plans to have a defined "=" operator on the point type? I
> can understand how the other geometric types, "=" would represent
> area, but AFAIK I think "=" could be safely applied on a point type
> (and i realize I could submit a patch for that :-) maybe depending on
> the resolution to this / refreshing my C...).

The built-in geometric types haven't received a lot of attention lately.
Most people who use geometric data use the PostGIS extension, which is a
sophisticated extension that can deal with that kind of data. You might
want to check that out and see if it meets your needs.

Perhaps someone is interested in bringing the built-in geometric types
up to speed; but I think most of the interest is moving things like this
out to extensions where they can be more easily be maintained by
interested parties.

If you'd like to submit a patch, I suggest first asking on -hackers
whether improvements to the built-in spatial types would be accepted.

Regards,
Jeff Davis