Objective

The objective of a physical model is to provide a database administrator with sufficient information to create an efficient physical database. The physical model also provides a context for the definition and recording (in the data dictionary) of the data elements that form the database, and assists the application team in choosing a physical structure for the programs that will access the data. To ensure that all information system needs are met, physical models are often developed jointly by a team representing the data administration, database administration, and application development areas.

When it is appropriate for the development effort, the model can also provide the basis for comparing the physical database design against the original business information requirements to:

• Demonstrate that the physical database design adequately supports those requirements.
• Document physical design choices and their implications, such as what is satisfied, and what is not.
• Identify database extensibility capabilities and constraints.