A semantic network approach to semi-structured documents repositories

Using database technology for the administration of digital Libraries offers many advantages in a multi-user and distributed environment. However, conventional DBMS are not particularly suited to manage semi-structured data with heterogeneous, irregular, evolving structures as in the case of SGML documents found in digital libraries. To overcome the difficulties imposed by the rigid schema of conventional systems, several schema-less approaches have been proposed. Using instead unconstrained, extensible schemata offered by object-oriented semantic network systems, we are able both to map document specific structures as database classes, and to model the associated constraint information as integrated schema annotations. In this paper we present the benefits of this approach to create, access and process heterogeneous SGML documents, and in particular to exploit the shared semantics of evolving SGML structures. A respective application is currently being implemented in the context of the AQUARELLE project.