The key of the SOURCE entity is introduced as a redundant property into the logical entity coming from the TARGET conceptual entity.
Example:
The key of the entity ORDER (Order_No) is duplicated into the entity DELIVERY as a property of this file.
The key of the SOURCE entity is introduced as a redundant property into the logical entity coming from the TARGET conceptual entity.
The key of the entity ORDER (Order_No) is duplicated into the entity DELIVERY as a property of this file.