— Accurate query performance prediction (QPP) is central to effective resource management, query optimization and query scheduling. Analytical cost models, used in current genera...
The semantic web represents meta-data as a relation of triples using the RDF data model. We have developed a virtual repository system that enables to process queries to RDF views...
This work addresses a problem of optimal query processing in heterogeneous and distributed multidatabase systems. The objective is to nd a method for opimization of global query p...
A new approach to query optimization, truly adaptive optimization (TAO), is presented. TAO is a general optimization strategy and is composed of three elements:
W3C currently extends the SPARQL query language with so-called entailment regimes, which define how queries are evaluated using logical entailment relations. We describe a sound a...