Relational Databases (RDB) are used as the backend database by most of information systems. RDB encapsulate conceptual model and metadata needed in the ontology construction. Schema mapping is a technique that is used by all existing approaches for ontology building from RDB. However, most of those methods use poor transformation rules that prevent advanced database mining for building rich ontologies. In this paper, we propose transformation rules for building owl ontologies from RDBs. It allows transforming all possible cases in RDBs into ontological constructs. The proposed rules are enriched by analyzing stored data to detect disjointness and totalness constraints in hierarchies, and calculating the participation level of tables in n-ary relations. In addition, our technique is generic; hence it can be applied to any RDB. The proposed rules were evaluated using a normalized and open RDB. The obtained ontology is richer in terms of non- taxonomic relationships
展开▼
