Abstrakt
The retrieval problem is one of the main reasoning problems for ontology based systems. The retrieval problem for concept C consists in finding all individuals a which satisfy C(a).
We present ontology transformation which can help to improve evaluating queries over (sublanguage of) OWL ontologies. Our solution is based on translating retrieval concepts into relational algebra expressions and consequently to SQL queries over a database constructed from the original ontology.
Ontology transformation into database is ontology-dependent but fully automatic and it is provided by system TORQue.