Ontology-based data access with MASTRO (demo

and the Semantic Web [4], clients need to access the services exported by the system, and hence require a representation of the intensional level of the application domain in terms of which they can specify the access to the exported services. One of the most interesting usages of such a shared conceptualization is ontology-based data access, where a conceptual layer is exported to the client, abstracting away from how actual data is maintained. Therefore, an ontology-based data access system has to adress the “impedance mismatch ” issue, existing between data actually present at the sources, and objects represented at the intensional level. In this demo, we present MASTRO, an ontology-based data access system that ex-tends the QuOnto system [1] with new capabilities and uses the QuOnto engine at its core. Specifically, MASTRO provides tractable reasoning over an ontology, laying over an autonomous relational DBMS managing the data layer. In what follows, we introduce the main services provided by MASTRO, namely (i) ontology specification, (ii) query answering, (iii) ontology satisfiability, and (iv) meta-query answering. The present work is one of the outcomes of the European project TONES1