You can use overview diagrams to better understand the interaction between data objects.
Overview diagrams are accessible from the Data Source Explorer or from a physical or logical model in the Data Project Explorer.
When you create an overview diagram, the preferences that you specify in the Preferences window are used to determine the appearance of the diagram. You specify the compartment display options after you create the overview diagram. All of the compartments of data objects are collapsed until you expand them in the diagram.
For logical data models, you can also create overview diagrams from multiple subpackages.
You can also add data objects to a new overview diagram by right-clicking the data objects in the Data Project Explorer and selecting Add to Overview Diagram.