Re: Off topic : world database
От | Oleg Bartunov |
---|---|
Тема | Re: Off topic : world database |
Дата | |
Msg-id | Pine.GSO.4.53.0304011924170.27392@ra.sai.msu.su обсуждение исходный текст |
Ответ на | Re: Off topic : world database (Bruno Wolff III <bruno@wolff.to>) |
Ответы |
Re: Off topic : world database
Re: Off topic : world database |
Список | pgsql-sql |
I don't know if it's legal to use data from http://www.nima.mil/gns/html/index.html but it's a huge collection of geo data. Oleg On Mon, 31 Mar 2003, Bruno Wolff III wrote: > On Mon, Mar 31, 2003 at 11:08:48 +0530, > Rajesh Kumar Mallah <mallah@trade-india.com> 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 > Regards, Oleg _____________________________________________________________ Oleg Bartunov, sci.researcher, hostmaster of AstroNet, Sternberg Astronomical Institute, Moscow University (Russia) Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/ phone: +007(095)939-16-83, +007(095)939-23-83
В списке pgsql-sql по дате отправления: