Physical Data Model
A Physical Data Model visually represents the structure of data as implemented by a relational database schema. 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 database Tables, columns, Primary keys and Foreign keys.
Example Data Model
This example shows a Physical Data Model that could be used to automatically generate a database schema. Each Table is represented by a UML Class; Table columns, Primary Keys and Foreign Keys are modeled using UML attributes and operations.
A Physical data model defined using a UML Profile and the Information Engineering notation
The example 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 identify cardinality in relationships.
Prior to creating a Physical Data Model it is advisable for you to set the default DBMS for the project. This pre-sets the default database for all new Table elements that you create.
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:
|·||The Project | Settings | Database Datatypes menu option, or|
|·||Tools | Options | Code Editors, or|
|·||The Code Generation Toolbar|
Learning Center topics
|·||(Alt+F1) | Enterprise Architect | Database Engineering|