Thread: PostgreSQL & r-trees

Hello everybody!

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.

Now I just would like to verify the information I have found in the
documentation. Does anybody have ever used this feature of the
PostgreSQL system?

--
Best Regards,
Steffen Zimmert


Steffen Zimmert
Fraunhofer Center for Research in Computer Graphics
Providence, Rhode Island, USA
email: szimmert@crcg.edu

>
> 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.

I have used the 'box' and 'line' objects in the past (ver 6.3 or so).
The use was short lived...to determine if specific satellite ordits
(modeled as straight lines) could cause RF safety zone (boxes)
violations (intersects) if we were to track them.  This application
worked well for the month or so it was needed.  I have done no other
work with these types since then.

> 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originally made for Illustra: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