Professional Microsoft® SQL Server® Analysis Services 2008 with MDX

Chapter 8. Advanced Dimension Design

In this look at advanced dimension design, you learn to aggregate data up to the parent member through custom rollup (aggregate) operations, and you learn about the effects of various dimension and hierarchy properties. For example, you would normally expect data to be aggregated along a dimension from a child to its parent. If you have a hierarchy such as Time, then sales per month will be rolled up to calculate first the sales of a quarter, and sales of a quarter will be rolled up to calculate the sales of a year. Even though this is the most common way a user would expect the data to be aggregated, there are dimensions in which the data does not get rolled up by a simple sum. You also learn about the Business Intelligence Wizard, which helps you to enhance cubes and dimensions with the logic and structure needed to solve common business problems. Finally, you are introduced to dimension writeback, which is a way to enable changes to the dimension structure, typically to facilitate "what if" analysis.

Consider first the details you already learned regarding dimension design back in Chapter 5; you learned that dimensions are made up of hierarchies, which in turn consist of tiers called levels. The two types of hierarchies, attribute and multilevel, were described, as well as two specific types of dimension constructs: Time and Parent-Child dimensions. The material in this chapter builds on the initial baseline that has been established to ...