Islands and query answering for Alchi-ontologies

The vision of the Semantic Web fostered the interest in reasoning over ever larger sets of assertional statements in ontologies. Today, real-world ontologies do not fit into main memory anymore and therefore tableaux-based reasoning systems cannot handle these large ontologies any longer. We propose strategies to overcome this problem by performing query answering for an ontology over (usually small) relevant subsets of assertional axioms, called islands. These islands are computed based on a partitioning-criteria. We propose a way to preserve the partitions while updating an ontology and thus enable stream like reasoning for description logic ontologies. Furthermore, we explain how islands can be used to answer grounded conjunctive queries for description logic ontologies. We think that our proposal can support description logic systems to deal with the upcoming large amounts of fluctuant assertional data.