Abstract:
Ontology based relational data bases access approach (OBDA) is a crucial main of semantic
web. In that approach, the user specifies a query, using the TBox of the ontology. This query is
rewritten into a set of queries. The rewritten queries are answered using the ABox of the ontology
only. In our case the ABox is represented by a relational data base and a mapping process between the
ontology and a data base is proposed.
The advantage of the OBDA is that a database query then should return not only the data that
is stored explicitly in the database, but also additional facts that can be inferred from it using the
ontological information by rewriting process.
There are many algorithms for rewriting problem, in this work we use the algorithm of D.
Calvanese which is based on description logics (DL). For this reason, we explore different family of
such DL. We discuss also, sublanguages of ontology web languages (OWL) and explain their
relationship with our problem.
