DataSetName Element (Data Regions) (RDL)
Indicates which dataset to use for the dataset reference or data region.
If the report contains more than one dataset, the DataSetName element is required for top-level data regions. If the report contains only one dataset, the data region uses that dataset. If the report does not contain any datasets, you cannot use data regions. DataSetName is ignored for data regions that are not contained by other data regions.