Query scrambling in distributed multidatabase systems

This work addresses the problem of efficient query processing in multidatabase systems distributed over wide-area networks. The solution unifies the query scrambling and reduction approaches to dynamic optimization of query processing plans at the data integration stage. The paper presents a new data integration algorithm based on query scrambling and the extended reduction technique. The algorithm both reschedules data integration operations and reductions of arguments and permits the concurrent computations of operations and reductions.