OLAP分析中一种有效的下钻路径裁减技术

0LAP技术为企业数据分析提供了极大的便利。然而，复杂的多维结构导致了复杂的下钻路径组合，从而使得用户的数据分析效率低下。解决OLAP分析中用户的探查路径过于复杂冗长是OLAP面临的主要问题之一，但是当前的研究成果大多由于与特定的分析任务相关而不能完全解决该问题。本文提出了一种与分析任务无关的下钻路径裁剪方法。该方法从多维数据结构本身出发将无效的下钻从分析过程中裁剪掉，从而达到了简化分析过程的目标。本文采用向量夹角法评估下钻操作的有效性，并给出了对应的高效下钻路径裁剪算法。该算法以有序的实事表为输入，只需一次扫描即可完成裁剪过程。实验结果证明了本文方法的可行性、高效性、抗稀疏性和抗偏斜性。

An Effective Drill-down Paths Pruning Method in OLAP

The OLAP provides a convenient way for data analysis.But the complexity of multi-dimensional data structure affects the efficiency of OLAP, because there are too many drill-down paths to be chosen from when analysis.How to prune the complex and tedious analysis paths is one of the major issues in this research field.While most methods in the literature are associated to some specific analysis tasks, so they cannot get reasonable effect.In this paper, we proposed a new method that is irrelevant to analysis task.In order to simplify the OLAP analysis process, we prune the invalid drill-down operations.The vetorial angle method is employed to evaluate the validness of every drill-down operation.We give the corresponding path pruning algorithm, and it is effective that it takes the fact table as the input in only one pass scanning.The experiments show that our method is feasible, effective, sparsity-proof and skewness-proof.