On Mon, Mar 31, 2003 at 11:08:48 +0530, Rajesh Kumar Mallah <[EMAIL PROTECTED]> wrote: > > I am wanting to make an application similar to you > which shud be able to get all the places within certaint > radius of the place in question.
If you look at contrib/earthdistance in the 7.4 source tree, there is a varient way to use earthdistance based on the cube data type instead of point. This varient uses a 3D representation so you don't have to worry about issues at the poles or wrap around. You can do indexed searches (though I don't really know how well (fast) the indexes work, since I haven't tried them with large amounts of data) inside of bounding boxes, then double check that the points are really closer than the desired distance. This varient uses a couple of new cube functions and check constraints on domains. You can just comment out the check constraints. The 7.4 contrib/cube might work with 7.3. (If there are problems you should be able to compare with the 7.3 version to figure out how to make it work.) P.S. It would be nice if you eventually summarize your data sources, as I would eventually like to get hold of similar data for areas outside of the US for my project. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
