Aggregation versus preaggregated values
The biggest advantage of using a cube as a data source is their capability to pre-aggregate values. This recipe will show you how to exploit this feature of cubes in your Cognos reports.
Getting ready
Create a simple crosstab report using the Sales and Marketing (cube) package. Drag Retailer name and Retailer site onto rows and Year onto columns. Drag Revenue onto the intersection.
How to do it...
In this recipe we will start by creating the aggregation using the Aggregate button as follows:
First, we will create aggregation using the standard method. For that, select the Retailer site row.
From the toolbar, click on the Aggregate button and choose Automatic Summary:
Run the report to test it:
Now go back to the Report Studio. Delete the new row created for Aggregation.
Go to the second tab (Data Item) of Insertable Objects. Drag Retailer name again onto the report and drop it under Retailer site and format this row to be bold; shown as follows:
Now run the...
