Fastest Way to Find Distance Between Two Lat/Long Points

Question

I currently have just under a million locations in a mysql database all with longitude and latitude information.

I am trying to find the distance between one point a

Answer 1

The following MySQL function was posted on this blog post. I haven't tested it much, but from what I gathered from the post, if your latitude and longitude fields are indexed, this may work well for you:

DELIMITER $$

DROP FUNCTION IF EXISTS `get_distance_in_miles_between_geo_locations` $$
CREATE FUNCTION get_distance_in_miles_between_geo_locations(
  geo1_latitude decimal(10,6), geo1_longitude decimal(10,6), 
  geo2_latitude decimal(10,6), geo2_longitude decimal(10,6)) 
returns decimal(10,3) DETERMINISTIC
BEGIN
  return ((ACOS(SIN(geo1_latitude * PI() / 180) * SIN(geo2_latitude * PI() / 180) 
    + COS(geo1_latitude * PI() / 180) * COS(geo2_latitude * PI() / 180) 
    * COS((geo1_longitude - geo2_longitude) * PI() / 180)) * 180 / PI()) 
    * 60 * 1.1515);
END $$

DELIMITER ;

Sample usage:

Assuming a table called places with fields latitude & longitude:

SELECT get_distance_in_miles_between_geo_locations(-34.017330, 22.809500,
latitude, longitude) AS distance_from_input FROM places;