This image shows the Overview tab of the Data Source Properties dialog that you use to modify data source column properties and data source permissions. The tab displays on the left the basic properties of the data source, including Name, Last Updated, Owner, and Description. You can edit the data source Description.

The right side of the tab displays the Columns table, which displays the properties of each column in the data source. The table includes the following columns: Name, Type, Treat As, and Aggregation. Each column in the data set is identified in the table as either an attribute or a measure in the Type column. You can change this property in the Treat As column. If a data set column is a measure type, you can specify how it is calculated in the Aggregation column, as shown in the image.