Roll Up a Subtype Relationship with a Transformation

You can roll up a subtype relationship with a transformation.

To roll up a subtype relationship with a transformation

1. Select the subtype relationship symbol .

   The Supertype-Subtype RollUp icon becomes active on the Transformations toolbar.

2. Click the Supertype-Subtype RollUp icon.

   The wizard opens.

3. Follow the instructions in the Supertype Subtype Roll-Up wizard.

   A supertype entity that contains all primary-key and non-key attributes from the source supertype and subtype entities is created.

When you run Supertype-Subtype RollUp process via erwin Data Modeler (DM) > Actions > Transformations > Supertype-Subtype RollUp, only a single, rolled-up state is maintained for the involved entities on logical and physical sides.

The Supertype-Subtype Transformation option enables you to maintain two states of relationships between entities. On the logical side, it maintains the involved entities. Whereas, on the physical side, it maintains the rolled-up entity.

For this option to take effect, do the following:

1. In erwin DM, on the Tools tab, click Options.
   The Options dialog box opens.
2. In the Diagram section, select Supertype-Subtype Transformation.
3. Click OK.
4. On the Logical side of your model, right-click the Subtype symbol and click Properties.
   The Subtype Symbol Editor opens.
   
5. Under Transformation Type, select RollUp.
6. Click Close.
   Supertype-subtype rollup transformation is applied on the Physical side of your model.

Note: For an already transformed target entity, any newly added non-key attributes in the child entity on Logical side are not rolled-up automatically. To roll-up the new attributes, rerun the roll-up action on the Logical side as follows:

1. On the Attribute Editor, clear the Logical Only check box and click Close.
2. On the Subtype Symbol Editor, set the Transformation Type to RollUp and click Close.

More information:

Using a Transformation to Roll Up a Subtype Relationship