Re: Zip code

News wrote:
> I have a database of zipcodes with latitude and longitude. I also have the
> method of calculating the distance between two zipcodes. What I want to
> know is if there is an efficient algorithm for obtaining the zip codes
> within a specified distance of the first zipcode without having to retrieve
> and calculate for every record in the database.

You may do that in the query itself; but the DB will definitely scan
all the records. Look at the previous discussions
<news:CWAVb.22832$VW4.3380@xxxxxxxxxxxxxxxxxxxxxxxxxx> (
http://groups-beta.google.com/group/comp.lang.php/msg/a1418b46576b2cd3
)

Indexing latitude and longitude might help.

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