[GRASS-user] Efficient vector spatial querying...

[Jonathan Greenberg]

I have two datasets, both with about 1 million points per dataset (lets 
call them A and B).  I'd like to know, for each point in A, what the 
closest point in B is (e.g. a spatial join).  I can (and am) doing this 
with the brute force method that ArcMap seems to use (e.g. comparing 
each point to every other point, which is a 1,000,000^2 searches), but 
is there any way to do this more efficiently?  Would a postgis database 
(queried through GRASS) work better?  Does GRASS even have a gui for 
doing postgis queries?  Thanks!

--j

-- 
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N
Davis, CA 95616
Cell: 415-794-5043
AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307