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OBI’s Nested Aggregation > Ralph Kimball

Ok so I put a provocative title on this post for a reason.  This post will explore why some of Kimball’s concepts may be out dated when newer query generation or database capabilities are taken into account.  Specifically, I’m going to discuss the OBI concept of Nested Aggregation, also known as Dimension Based Aggregation, in detail.  Using this OBI Modeling technique you can relax a bit on one of the Kimball Dimensional Modeling rules.  I’ll show how it works in a simplified manner, plus identify some things to be careful with and how it does not alleviate you from doing real modeling work. Read the rest of this entry