Copyright 2002 by
Prentice Hall, Inc.
7-12
Managing Data: The Three-Level Database Model
See Figure 7-4
nLevel 1 - The
external, conceptual, or local level, containing the various “user views” of the corporate data that each application program uses
nLevel 2 - The logical or “enterprise data” level, encompassing all an organization’s relevant data, under the control of the data administration.
nLevel 3 - The
physical or storage level, specifying the way the data is physically stored