Pushing down bit filters in the pipelined execution of large queries

Abstract

We propose a new strategy to use Bit Filters for complex pipelined queries on large databases that we call Pushed Down Bit Filters. The objective of the strategy is to make use of the Bit Filters already created for upper nodes of the execution plan, in the leaves of the plan. The aim of this strategy is to reduce the traffic between the nodes of the execution plan. When traffic is reduced, the amount of CPU work is reduced and, in most of the cases, I/O is also reduced. In addition, this technique shows no degradation in cases with little effectiveness. © Springer-Verlag 2003.