[GENERAL] point types in "DISTINCT" queries

[Jonathan S. Katz]

Hi,

I am running PostgreSQL 9.0.4 and I am getting an error with a SELECT DISTINCT 
query that contains a point type in the SELECT clause.  To be more specific, a 
query such as:

        -- explicit declaration that it's a point type
        SELECT DISTINCT a.geocode::point 
        FROM a
        WHERE a.region = 'x';

Will return the error:

        ERROR:  could not identify an equality operator for type point

I read the notes about how point types do not have "=" defined for them, but 
"~=" aka the "same as" operator 
(http://www.postgresql.org/docs/9.0/static/functions-geometry.html).  For 
points, I would treat ~= as equality.  I tried creating my own equality 
operator based on that:

        CREATE OR REPLACE FUNCTION point_equality(point, point) RETURNS bool
                AS 'SELECT $1 ~= $2;'
                LANGUAGE SQL;

        CREATE OPERATOR = (
                LEFTARG = point,
                RIGHTARG = point,
                PROCEDURE = point_equality,
                COMMUTATOR = =
        );

And when I ran the query again:

        ERROR:  could not identify an equality operator for type point

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.  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...).

Is there possibly a relatively quick solution to this issue?

Thanks!

Jonathan