Using Topic Maps to Extend Relational Databases
http://www.xml.com/pub/a/2003/03/05/tmrdb.html

de Graauw, Marc
XML.com
2003

Abstract:

Topic Maps provide a very flexible and robust way to add arbitrary data to a relational databases at runtime. Moreover, Topic Maps come with a predefined exchange mechanism (the XML Topic Maps (XTM) interchange syntax) to allow data to be exported to XML.