Again, I have a function that works fine locally, but moving it online yields a big fat error... Taking a cue from a response in which someone had pointed out the number of arguments I was passing wasn't accurate, I double-checked in this situation to be certain that I am passing 5 arguments to the function itself...

Query failed: ERROR: operator does not exist: point <@> point HINT: No operator matches the given name and argument type(s). You may need to add explicit type casts.

The query is this:

BEGIN; SELECT zip_proximity_sum('zc',                                                                                                                                                                  
    (SELECT g.lat FROM geocoded g                                                                                                                                                                              
    LEFT JOIN masterfile m ON g.recordid = m.id                                                                                                                                                                
    WHERE m.zip = '10050' ORDER BY m.id LIMIT 1),                                                                                                                                                             
    (SELECT g.lon FROM geocoded g                                                                                                                                                                              
    LEFT JOIN masterfile m ON g.recordid = m.id                                                                                                                                                                
    WHERE m.zip = '10050' ORDER BY m.id LIMIT 1),                                                                                                                                                             
    (SELECT m.zip FROM geocoded g                                                                                                                                                                              
    LEFT JOIN masterfile m ON g.recordid = m.id                                                                                                                                                                
    WHERE m.zip = '10050' ORDER BY m.id LIMIT 1)                                                                                                                                                              
    ,10);

The PG function is this:

CREATE OR REPLACE FUNCTION zip_proximity_sum(refcursor, numeric, numeric, character, numeric)
  RETURNS refcursor AS
$BODY$ 
    BEGIN 

        OPEN $1 FOR 
            SELECT r.zip, point($2,$3) <@> point(g.lat, g.lon) AS distance
            FROM
            geocoded g LEFT JOIN masterfile r ON g.recordid = r.id 
            WHERE (geo_distance( point($2,$3),point(g.lat,g.lon)) < $5)
            ORDER BY r.zip, distance;
        RETURN $1; 
    END; 
    $BODY$
  LANGUAGE 'plpgsql' VOLATILE
  COST 100;