Maintaining integrity constraints in relational to OWL transformations

A large portion of the Semantic Web is expected to be generated from the hidden Web of relational databases. The methods to translate relational content to OWL/RDF are reasonably straightforward, however these methods tend to lose most, if not all, important integrity constraints that are present in the relational data. In this paper, we present a para-consistent logic based method to maintain several important categories of relational integrity constraints while translating relational data into OWL. In addition, we are able to further enforce OWL-like constraints on the resulting RDFs which are essential to fully exploit the expressiveness and logical inference power of OWL. Most importantly, with our method, the problem of inconsistency checking of OWL instances reduces to simple instance matching within two classes.