We present an optimization method and algorithm designed for three objectives: physical data independence, semantic optimization, and generalized tableau minimization. The method ...
We state and solve the query reformulation problem for XML publishing in a general setting that allows mixed (XML and relational) storage for the proprietary data and exploits redu...
SPKI/SDSI is a language for expressing distributed access control policy, derived from SPKI and SDSI. We provide a first-order logic (FOL) semantics for SDSI, and show that it ha...
In the study of data exchange one usually assumes an openworld semantics, making it possible to extend instances of target schemas. An alternative closed-world semantics only move...
Abstract. Semistructured data has no absolute schema xed in advance and its structure may be irregular or incomplete. Such data commonly arises in sources that do not impose a rigi...