The Importance of IS Management

Prentice Hall, Inc.

7-13

The Three-Level Database Model: Advantages

nLogical data can be separated from the method of physical storage, different physical devices can be used without changing application programs. nLogical data relationships can vary from different programs that use the data, without requiring data redundancy. nApplications can use a subset of the DB and organize it, again without redundancy, in the best manner for the application.