A universal model of a database D and a set Σ of integrity constraints is a database that extends D, satisfies Σ, and is most general in the sense that it contains sound and co...
XPath is the standard language for addressing parts of an XML document. We present a sound and complete decision procedure for containment of XPath queries. The considered XPath f...
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...
Abstract. We give a general framework for approximate query processing in semistructured databases. We focus on regular path queries, which are the integral part of most of the que...
This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic DLR and point-based linear ...