Flexible Design and Efficient Implementation of a Hypermedia Document Database System by Tailoring Semantic Relationships

In this paper we present the design concepts and data modeling approach that was used to define a general application framework for storing hypermedia documents in the object-oriented database management system VODAK. We exploit the capabilities of the VODAK data model to introduce new hypermedia modeling primitives at the meta level. We show that representing the hypermedia semantics within the DBMS in this way is clearly advantageous for efficiency of the design and implementation of hypermedia document storage engines. As an example, we give a concrete realization of a DBMS-based hypermedia engine for the SEPIA hypermedia authoring system developed at GMD-IPSI. With this example we show that the data model extensions provided are flexible enough to represent also complex semantic hypermedia concepts, that the development cycle of a hypermedia engine can become extremely fast and that the resulting implementation has adequate performance for interactive applications.