What is the intention of the Two Table Roll Up Transformation and how do I apply it to my model?
You can apply a transformation to roll up and denormalize two related tables and create a single table. Denormalization improves query performance and helps build a more effective physical model for a target DBMS.
Important! Once you apply the Two Table Roll Up transformation, it cannot be reversed. While in the current modeling session however, you can undo the action.
To roll up and denormalize two tables, please take the following steps:
1. Go to the Actions menu and select the dropdown Transformations > select the identifying relationship that connects the two tables > select the Two Table Roll Up icon on the Transformations:
2. The Table Denormalization Roll Up Wizard will then prompt you to roll up the child table into its parent table > confirm the Number of records and click the Next button:
3. Complete the Table Denormalization Roll Up by selecting the Finish button:
4. After the Table Denormalization Roll Up is confirmed the Child Table will be removed from the ER Diagram
1. Using the Two Table Roll Up Transformation: https://erwin.com/bookshelf/public_html/2020R1/Content/User%20Guides/erwin%20Help/use_a_transformation_to_roll_up_and_denormalize_two_tables.html
2. Roll Up and Denormalize Two Tables with a Transformation: https://erwin.com/bookshelf/public_html/2020R1/Content/User%20Guides/erwin%20Help/Roll_up_and_denormalize_two_tables_with_a_transform.html