Specifying dynamic aggregation functions

Steps to set the dynamic aggregation function

Before you begin

• You must have the MicroStrategy OLAP Services product to use the dynamic aggregation function. If you would like to evaluate OLAP Services, contact your MicroStrategy Account Executive or email MicroStrategy directly at info@microstrategy.com.

• This topic assumes a basic understanding of levels. See About level metrics for an introduction and, for further details, the Advanced Metrics chapter of the Advanced Reporting Help.

Dynamic aggregation occurs when you move an attribute from the report grid to the Report Objects pane. The metric values roll up to the new attribute level of the grid. Whenever the attributes in Report Objects are not the same as the attributes on the grid, dynamic aggregation has occurred. Dynamic aggregation happens on the fly, in memory. This ability to roll up data in memory is useful for quick report interaction and analysis.

The Analytical Engine selects the best aggregation function to use, by default, according to these rules:

• If the metric is compound, sum is used as the aggregation function.

• If the metric is a sum, maximum, minimum, or other expression that can be recalculated, the metric's expression is used.

• If the metric cannot be recalculated dynamically, as with an average or count distinct, the metric values are replaced with dashes to signify that the metric cannot be calculated dynamically at this level.

You can also specify the function to use when the Analytical Engine aggregates the metric, using the dynamic aggregation setting. You can use any of the standard predefined subtotal functions or the user-defined subtotals.

However, not all metrics can be rolled up with an additional aggregation function. If the data is required at the higher level, it first must be recalculated from the more detailed data available only in the data warehouse.

For additional information on and examples of dynamic aggregation, refer to the In-memory Analytics Help.

Prerequisite

You must have the MicroStrategy OLAP Services product to use the dynamic aggregation function. If you would like to evaluate OLAP Services, contact your MicroStrategy Account Executive or e-mail MicroStrategy directly at info@microstrategy.com.

To set the dynamic aggregation function

1. Open the metric in the Metric Editor. (How?)

2. Click the Subtotals/Aggregation tab.

3. From the drop-down list in Dynamic aggregation function, select the function to use when the metric is rolled up on a report.

   Leaving the function as Default allows the Analytical Engine to select the best aggregation function to use based on the following rules:

   • If the metric is compound, sum is used as the aggregation function.

   • If the metric is a sum, maximum, minimum, or other expression that can be recalculated, the metric's expression is used.

   • If the metric cannot be recalculated dynamically, as with an average or count distinct, the metric values are replaced with dashes to signify that the metric cannot be calculated dynamically at this level.

4. Click Save and Close to save the metric and close the Metric Editor.