parallel processing
parallellism plays a singnificant role in processing massive databases. Teradata pioneered some of the sky technology. All major vendors of databases management systems now offer data partitioning and parallel query proceseeing technology. The artcle by Dewitt and Gray provides an overview of this area28. One interesting support systems is that of read-only environment of decision sport systems is that of piggybacking scans requested by multiplenqueries used in Redbrick. Piggybacking scan redues the total work as well as respones time b overlapping scans of multiple concurrent requests