Professional Microsoft® SQL Server® Analysis Services 2008 with MDX

6.4. Measures and Measure Groups

You learned about editing cube dimensions and establishing the right relationships between dimensions and measure groups in a cube. Similarly, you can add or delete measures and measure groups in a cube. Measures are the focus point for data analysis and therefore they are the core objects of a cube. Measures are columns from the fact table that contain meaningful information for data analysis. Usually measures are of type numeric and can be aggregated or summarized along hierarchies of a dimension. You can specify the type of aggregation to be applied for each measure. The most widely used aggregate functions are Sum, Count, and Distinct Count. A collection of measures forms an object called a measure group, and a collection of measure groups forms the dimension called Measures in the cube. "Measures" is a keyword in Analysis Services that refers to a special dimension that only contains the fact data.

If you click the Cube Structure tab in the cube editor you will see the Measures pane on the top-left corner. Click the cube named Adventure Works DW within the Measures pane to see the associated properties in the Properties window located on the bottom-right corner of the BIDS. Figure 6-17 shows the Measures and Properties panes. The Measures pane shows the cube name and the measure groups within the cube. You can see the two measure groups Fact Reseller Sales and Fact Internet Sales that correspond to the two fact tables. Fact table columns that ...