Use the data model editor to combine data from multiple data sets from different data sources such as SQL, Excel files, Web services, HTTP feeds, and other applications into a single XML data structure. You can user data sets that are unrelated or establish a relationship between the data sets using a data link.
The data model editor enables you to perform the following tasks:
Link data - Define master-detail links between data sets to build a hierarchical data model.
Aggregate data - Create group level totals and subtotals.
Transform data - Modify source data to conform to business terms and reporting requirements.
Create calculations - Compute data values that are required for your report that are not available in the underlying data sources.