Incremental Maintenance of Materialized Ontologies

This paper discusses the incremental maintenance of materialized ontologies in a rule-enabled Semantic Web. Materialization allows to speed up query processing by explicating the implicit entailments which are sanctioned by the semantics of an ontology. The complexity of reasoning with the ontology is thereby shifted from query time to update time. We assume that materialization techniques will frequently be important to achieve a scalable Semantic Web, since read access to ontologies is predominant. Central to materialization are maintenance techniques that allow to incrementally update a materialization when changes occur. We present a novel solution that allows to cope with changes in rules and facts. To achieve this we extend a known approach for the incremental maintenance of views in deductive databases. We show how our technique can be employed for a broad range of existing Web ontology languages, such as RDF/S and subsets of OWL and present a first evaluation.