Physical Data Model

Benefit

In addition to providing a visual abstraction of the database structure, an important benefit of defining a Physical data model is that you can automatically derive the database schema from the model.

This is possible due to the richness of meta-data captured by a Physical data model and its close mapping to aspects of the database schema, such as tables, columns, primary and foreign keys.

Data Models

Example

The following is an example of a Physical data model that could be used to automatically generate a database schema.

Each table is represented by a UML Class; columns, including Primary and Foreign Keys, are modeled using UML attributes and operations.

A Physical data model defined using a UML Profile and the Information Engineering notation

Notation

The above model is defined using Enterprise Architect's UML Profile for Data Modeling; the relationship between the tables uses the Information Engineering notation.

Information Engineering is one of three notations that Enterprise Architect supports to help Data Modelers distinguish cardinality in relationships.

Data Modeling Notations

Connectors Tab

Set Default DBMS

Prior to creating a Physical data model it is advisable to set the default DBMS. This pre-sets the default database when you create any new Table elements.

If the DBMS is not set, Tables are created without a DBMS type and field typing cannot be allocated when creating new fields in the table.

You can set the default DBMS type using either:

Add New Datatypes

Set the Database Type

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