Simple Oracle SQL haversine distance calculation

haversine_distance_oracle.sql

-- Simple Oracle SQL haversine distance. 
-- Most likely you will want to put this into a CTE.
-- Not suitable for high-accuracy. Answer will be in km.
-- Still requires sdo for at least the degrees to radians conversion.
SELECT descript, ( /* Approx. Earth radius in km:*/ 6371 * acos(
                        cos(SDO_UTIL.CONVERT_UNIT(Lat1, 'Degree', 'Radian')) * 
                        cos(SDO_UTIL.CONVERT_UNIT(Lat2, 'Degree', 'Radian')) * 
                        cos(SDO_UTIL.CONVERT_UNIT(Lon2, 'Degree', 'Radian') - SDO_UTIL.CONVERT_UNIT(Lon1, 'Degree', 'Radian') ) 
                        + sin(SDO_UTIL.CONVERT_UNIT(Lat1, 'Degree', 'Radian')) * sin(SDO_UTIL.CONVERT_UNIT(Lat2, 'Degree', 'Radian'))
            )) AS haversine_distance 
FROM  (
    select
        'smithsonian to kenedy space center ~ 1195km' descript,
        38.88978542398205 lat1, -77.02088373582937 lon1, 
        28.651877187556792 lat2, -80.68296750105196 lon2
    from dual
    UNION
    select
        'walk across the goldengate bridge ~ 1.7k' descript,
        37.810545958442475 lat1, -122.47710002669695 lon1, 
        37.826268071897346 lat2, -122.47902012968235 lon2
    from dual
) some_table_with_lat_longs_as_simple_numbers
;