一种数据仓库数据立方体空间采样估计策略
A CUBE SIZE ESTIMATION STRATEGY OF DATA WAREHOUSE BASED ON SAMPLING
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摘要: 对数据仓库多维视图进行容量估计是数据立方体设计、数据仓库存储规划和实施查询优化的基础 .首先以统计理论为基础 ,提出了一种基于采样的数据仓库数据立方体空间估计策略 .该策略针对不同类型的多维视图 ,对样本统计结果采用不同的空间放大策略 ,确保了估计结果具有较高的准确性 .同时 ,该策略在最大估计的基础上采用一些启发式规则 ,对估计视图集进行有效的约简 ,并在估计过程中采用了样本视图预物化思想 ,根据预物化视图集生成优化的立方体空间估计序列 ,从而大幅缩短了整体估计时间 .Abstract: Size estimation of multidimensional views of data warehouse is a fundamental step for data cube design, warehouse storage planning, and query optimization. In this paper, a sampling-based cube size estimation strategy of data warehouse based on statistical theories is proposed. It applies different sampling size enlargement strategies to different kinds of views to ensure a satisfactory accuracy. Furthermore, It applies some heuristic rules in reducing the cube views according to the result of maximum estimation. An idea of sampling view pre-materialization is also proposed, which may result in a pre-materialized view set for generating an optimal estimation sequence of cube views that sharply reduces the total estimation time.
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