Optimizing global query processing plans in heterogeneous and distributed multidatabase systems

Abstract

The article addresses a problem of optimal query processing in heterogeneous and distributed multidatabase systems. The objective is to find a method for optimization of global query processing plans. Two generic strategies of query processing in heterogeneous and distributed systems include entirely sequential and entirely parallel approaches. The paper describes a hybrid strategy where some of the subqueries are submitted and processed sequentially while the others are processed in parallel. Optimization of query postprocessing is proposed and described in order to reduce an impact of errors in estimation of processing costs at the local systems.