We study the problem of rewriting queries using views in the presence of access patterns, integrity constraints, disjunction, and negation. We provide asymptotically optimal algori...
Most state-of-the-art approaches of securing XML documents are based on a partial annotation of an XML tree with security labels which are later propagated to unlabeled nodes of th...
Abstract. Rewriting of conjunctive queries using views has many applications in database and data integration. We investigate ways to improve performance of rewriting and propose a...
XPath [3, 5] is a powerful and quite successful language able to perform complex node selection in trees through compact specifications. As such, it plays a growing role in many ...
A Community Web portal is a set of tools for a community of people who want to share information on a certain domain via the Web. The backbone of this system is an ontology which ...