Calculated measures are measures derived from other (stored or calculated) measures available in the cube. The calculations are specified as an MDX formula. The formula is saved in the cube schema definition. No calculated data is stored; the calculation is performed at query execution time.
Rather than requesting a restructuring of your fact table to have an additional column, creating a calculated measure allows the cube administrator to quickly add new measures that can be used in ad hoc query and reporting for timely business intelligence.
To include a fact table column in a calculated measure, the column must first be defined as a measure using Teradata Schema Workbench.
MDX looks similar to SQL, but is actually quite different and conceptually more complicated. For more information, refer to the following books:
- Fast Track to MDX (Whitehorn, Zare, and Pasumansky 2006)
- MDX Solutions, 2nd edition (Spofford and Harinath 2006)