Domains and Data Modeling › Domains in the Physical Model

Domains in the Physical Model

A domain includes both logical and physical properties. When you work in a physical model, a domain can include any or all the properties that you can assign to an individual column, including physical name, comment, data type, null option, default value, validation rule, and physical user-defined properties. For servers that provide native application development tools, you can also include server-side column display properties such as the column label.

The following pre-defined domains are available in every model:

• The <default> domain is the root domain in the physical hierarchy. The <default> domain is assigned automatically to all columns that have not been assigned a true domain. Properties defined by the domain include the default data type and null option selected for the target server.
• The Blob, Datetime, Number, and String domains are children of the <default> domain. You can assign a domain to a column in the physical model to define a data type for that column. Each of these child domains represents a single logical data type in the logical model.

In a physical model, the data type for Blob, Datetime, Number, and String are automatically assigned based on the default data types set for the target server selected. You can override the default data type and any of the other properties (except names and parent domains) for these domains in the Domain Editor.

More information:

Add a Domain in the Physical Edit Mode

Specify That a Domain Appears in the Physical Model Only

Change a Physical Domain Name

Add a User-Defined Data Type in a Physical Model

Domain Inheritance and Overrides

Specifying Database-Specific Options For a Domain

Specify a Domain Comment in the Physical Model

Specify a Data Source For a Domain

Specify a Validation Rule and Default Value for a Domain in the Physical Model