Re: Spatial Databases

In article <R6vt9.623$yK6.58309_at_newsfep1-win.server.ntli.net>, Ian <kellizer.remove_at_hotmail.remove.com> wrote:
>Hi all. Over the past few weeks, I'am starting to hear alot more about
>spatial database, and my question is, What are they, and how do they differ
>to RDBMS, and when would you use them over the relation database?

• What are they?

A spatial DBMS is a DBMS that has special support for storing spatial (or other multidimensional) data. Roughly that means that it (1) has special indexing methods for this data, (2) has special operators in its query language to query this data (or even a special graphical query interface), (3) knows how to do query optimization for these special operators and (4) has ways to present the spatial data in the result of a query in a user-friendly way on your screen or some other medium.

• How do they differ from RDBMSs?

An RDBMS can be a spatial DBMS if it supports the right features, and so can an OODBMS or an ORDBMS. So it is not a matter of choosing between an RDBMS and an SDBMS.

>Does anybody have any links to information on Spatial databases?

There's a nice lightweight tutorial on-line:

  http://www.dbnet.ece.ntua.gr/~theodor/tutorial/

Another interesting (but more theoretical) introduction:

  Paredaens, J., "Spatial Databases, The Final Frontier," Proceedings of   1995 International Conference of Database Theory, (edited by G. Gottlob   and M. Vardi), pp. 14-32, Lecture Notes in Computer Science 893,   Springer-Verlag, 1995.

  http://citeseer.nj.nec.com/paredaens95spatial.html

For an example of spatial extensions in commercial (O)RDBMSs see for example the Oracle Spatial Option in Oracle 9i:

  http://otn.oracle.com/products/spatial/htdocs/data_sheet_9i/9iR2_spatial_ds.html

Good luck,

• Jan Hidders