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On Propagation of Reduction Effects of a Semijoin in Distributed Query Processing.

dc.contributor.authorKang, Hyunmoen_US
dc.contributor.authorRoussopoulos, N.en_US
dc.description.abstractIn distributed query processing, the semijoin is used as an effective operator in reducing relations referenced in the query and thus reducing the total amount of data transmission. A semijoin is associated with two quantities: cost and benefit. These two quantities of semijoins are the useful ingredients in many heuristic algorithms proposed to generate a semijoin program which is a sequence of semijoins and is executed as a query pre- processing strategy. In this paper, in addition to the cost and benefit, we associate a semijoin with the third quantity: reduction propagation. It measures the propagation of reduction effects of a semijoin to other semijoins. We define this propagation in the context of distributed query processing and by precisely quantifying it, we present a heuristic algorithm to generate a semijoin program. The simulation reaults show that the new algorithm provides a considerable improvement over those based only on the cost and benefit.en_US
dc.format.extent570869 bytes
dc.relation.ispartofseriesISR; TR 1986-53en_US
dc.titleOn Propagation of Reduction Effects of a Semijoin in Distributed Query Processing.en_US
dc.typeTechnical Reporten_US

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