Using Dimension Calculation Groups
When you need to create and maintain a large set of calculations you can do this with calculation groups.
Introduction
Dimension calculation groups offer data architects a simplifying alternative to calculated metrics by enabling the expression of boiler-plate calculations across multiple metrics. This feature defines calculations as dimension members, and removes static references to individual metrics. At run-time, workbook authors evaluate the dimension calculations over an arbitrary set of metrics.
Using this feature, the number of calculated metrics in a model can be reduced by a factor equal to the number of metrics in the model. For example, using calculated metrics to perform three boiler plate calculations, such as Year-Over-Year-Growth, Year-To-Date-Growth, 30-Day-Moving-Average, across ten metrics requires the creation of 30 calculated metrics. Alternatively, the same use-case may be addressed by defining only three calculations in a time dimension calculation group. The end-user specifies the set of metrics at query execution time. The number of calculated metrics that must be maintained is reduced from 30 to three, a ten-fold reduction in complexity.
Creating calculation groups
Calculation groups are defined by the calculation_groups property
within SML dimension files. For more information, see
the AtScale SML Object Documentation on GitHub.
Before you start creating calculation groups, you should familiarize yourself with the basic concepts provided in Introduction to Calculations.
Working with Calculation Groups
For information on working with calculation groups in BI tools, see the following: