Question

I want to better understand what is required in order to implement a geo-spatial (aka proximity) search. I’d appreciate clarification on the following:

1. Beyond the latitude & longitude for
   corresponding zip codes, what if
   anything, is required?

2. Can anyone recommend any resources (books,
   websites, etc.) for understanding
   the formulas that can be used to
   calculate proximity such as:
   Haversine, Vincenty, Spherical?

3. How easy and effective are Mysql’s tools for
   implementing proximity searches?

4. Does Google Maps have an API for
   proximity searches? For example if I
   provide, a zip code can it return
   zip codes within a set radius? I
   searched the Google Maps website but
   found nothing of the sort.

Thanks.

Answer 1

1. You just need to do a lookup on the zip code against a lat/lon. You can get this data at some of these sites.

2. This is a good reference for Haversine / great circle calculations.
3. MySQL apparently has a geometry type that can be used for some of this. There are also other Spatial Database that might be more useful.

4. I’ve never heard that it has that capability, but that doesn’t mean that it can’t. It might be better to look to one of the spatial databases listed at the link above.