The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...
We study the problem of query optimization in federated relational database systems. The nature of federated databases explicitly decouples many aspects of the optimization proces...
Abstract. Sensor networks represent a non traditional source of information, as readings generated by sensors flow continuously, leading to an infinite stream of data. Traditiona...
We study the problem of finding efficient equivalent viewbased rewritings of relational queries, focusing on query optimization using materialized views under the assumption that ...
Cloud storage is an emerging infrastructure that offers Platforms as a Service (PaaS). On such platforms, storage and compute power are adjusted dynamically, and therefore it is i...