I've searched the mailing list archives, the web, read the FAQ, etc and I don't see anything relevant so here it goes…
I'm trying to implement a radius based searching based on zip/postal codes. (The user enters their zip code and I show nearby matches under x miles away sorted by linear distance.) I already have the data required to pull this off (zip codes, long/lat coordinates, etc.) Extreme accuracy is not a requirement. It just needs to be an approximation (plus or minus a few miles.) What I'm looking for is a little direction. How have others implemented this type of search? What are the pros/cons of various methods? I have a few ideas but obviously none of them are very good or I guess I wouldn't be here asking. ;) By the way, my index is updated about every 10 minutes and holds about 25,000 records. However, this may increase in the next year or so to hundreds of thousands. So whatever I do needs to be fairly scalable. The items being searched as well as the people searching will be located all over the world. Some areas may be busier than others so there is an opportunity for caching more common locals. Thank you for your time. I'd appreciate any suggestions that you can give. - Mike