一、基础知识
1. 大数定律
(1)切比雪夫大数定律
设 X 1 , X 2 , ⋯ , X n X_1,X_2,\cdots,X_n X1,X2,⋯,Xn是一列相互独立的随机变量,他们分别存在期望 E ( x k ) E(x_k) E(xk)和方差 D ( x k ) D(x_k) D(xk)。若存在常数 C C …
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Basics of Cube Aggregates and Data Rollup 发贴人 Jaya Tiwari 在 SAP Business Warehouse 打开 2013-7-7 9:39:58 inShare Tweet What are Cube Aggregates? Definition An aggregate is a materialized, summarized and condensed view of the data in an Info Cube. An a…