含有非独立型触发环的主动规则集归约算法研究

The Study on the Rule Reduction Algorithm about an Active Rule Set with Dependent Triggering Cycles

可终止性判定问题是主动数据库的一个核心问题。现有的研究工作提出了运用触发图和活化图的方法解决这个问题,其中的一个关键技术就是利用归约算法对主动规则集进行归约。已有的计算方法对一些可归约规则无法识别。本文提出了独立型触发环、非独立型触发环、活化路径、禁止活化环、禁止活化规则等概念。基于这些概念,提出了一个新的归约算法,从而可识别出更多的可归约规则。

Termination decision of an active rule set is an important problem in active database. Several recent works have suggested to prove termination using triggering and activation graphs. In these works, a crucial problem which should be solved is to compute the irreducible rule set of an active rule set. But the existing approaches cannot recognize some rules which should be reduced. Such concepts as independent triggering cycle, dependent triggering cycle, activation path, inhibited activation cycle and inhibited activation rule are presented in this paper. Based on these concepts, an improved rule reduction algorithm is given and much more reducible rules can be recognized through it.