> I was looking for a DBMS that supports multidimensional index structures
> like rectangles and points. During my search I found the link to the
> PostgreSQL system.
It does have the R-tree access method and a set of 2-D object types,
such as points, rectangles and polygons. It is also extensible enough
to allow adding custom types, although writing an R-tree interface for
a new type is quite a chore. It's doable, but I'd rather die. To make
things easier, a more generalized access method, named GiST, had been
built on top of R-tree (http://gist.cs.berkeley.edu/). That's what I
used to index 1-D intervals (example: http://wit.mcs.anl.gov/EMP/).
As an exercise, I also built a multidimensional box type off the code
originally made for Illustra:
http://best.me.berkeley.edu/~adong/rtree/index.html
My version is available at:
http://wit.mcs.anl.gov/~selkovjr/ndbox.tgz
HTH,
--Gene
