A method for the unification of XML schemata

Extensible Markup Language (XML) is a common standard for data representation and exchange over the Web. Considering the increasing need for managing data on the Web, integration techniques are required to access heterogeneous XML sources. In this paper, we describe a unification method for heterogeneous XML schemata. The input to the unification method is a set of object-oriented-based canonical schemata that conceptually abstract local Document Type Definitions of the involved sources. The unification process applies specific algorithms and rules to the concepts of the canonical schemata to generate a preliminary ontology. Further adjustments on this preliminary ontology generate a reference ontology that acts as a front-end for user queries to the XML sources.