VisAVis: An Approach to an Intermediate Layer between Ontologies and Relational Database Contents

This paper introduces an approach to mapping relational database contents to ontologies. The current effort is motivated by the need of including into the Semantic Web volumes of web data not satisfied by current search engines. A graphical tool is developed in order to ease the mapping procedure and export enhanced ontologies linked to database entities. Moreover, queries using semantic web query languages can be imposed to the database through its connection to an ontology. Using Protégé, we were able to map ontology instances into relational databases and retrieve results by semantic web query languages. The key idea is that, instead of storing instances along with the ontology terminology, we can keep them stored in a database and maintain a link to the dataset. Thus, on one hand we achieve smaller size ontologies and on the other hand we can exploit database contents harmonizing the semantic web concept with current wide-spread techniques and popular applications.