Hybrid-Range Partitioning Skate y: A New Deelustering Strategy for Multiprocessor 8 atabase Machines

In shared-nothing multiprocessor database machines, the relational operators that form a query are executed on the processors where the relations they reference are stored. In general, as the number of processors over which a relation is declustered is increased, the execution time for the query is decreased because more processors are used, each of which has to process fewer tuples. However, for some queries increasing the degree of declustering actually increases the query’s response time as the result of increased overhead for query startup, communication, and termination. In general, the declustering strategy selected for a relation can have a significant impact on the overall performance of the system. This paper presents the hybrid-range partitioning strategy, a new declustering strategy for multiprocessor database machines. In addition to describing its characteristics and operation, its performance is compared to that of the current partitioning strategies provided by the Gamma database machine.