Horizontal Aggregation using SPJ Method and Equivalence of Methods
K. Anusha, P. Radhakrishna, P. Sirisha · 2012
We introduced a new class of extended aggregate functions, called horizontal aggregations which help preparing data sets for data mining and OLAP cube exploration. Specifically, IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. 14 horizontal aggregations are useful to create data sets with a horizontal layout, as commonly required by data mining algorithms and OLAP cross-tabulation. Basically, a horizontal aggregation returns a set of numbers instead of a single number for each group, resembling a multi-dimensional vector. We proposed an abstract, but minimal, extension to SQL standard aggregate functions to compute horizontal aggregations which just requires specifying sub grouping columns inside the