Relationships and Domains › Domains and Data Modeling › Domains in the Physical Model › Define Basic Domain Physical Properties

Define Basic Domain Physical Properties

In a physical model based on either the MySQL, ODBC, SQL Server 2000, or Sybase target server, the <database> tab in the Domain Editor contains options for defining common domain properties such as physical data type and null option.

To define domain physical properties

1. Click Domains on the Model menu.

   The Domain Editor opens.

2. Select the domain in the Navigation Grid that you want to define.

   Note: Click New on the toolbar to create a new domain. Use the Enter filter text box to filter a very large list of domains to quickly locate the one that you want to define.

3. Click the <database> tab and work with the following options:

   Physical Data type

   Lets you select a data type from the drop-down list to apply to the selected domain. If the selected data type requires a value for precision, scale, or both, enter the value inside the data type parentheses. For example, you can select the DECIMAL() data type and specify a precision of 2 and a scale of 10 inside the parentheses to assign the data type DECIMAL(2,10) to the selected domain.

   Null Option

   Lets you specify a null option.

   Average Width

   Lets you enter an estimated average width for columns if variable width is allowed based on the data type you assigned. If it is not allowed, an error is displayed in the Details section at the bottom of the editor. You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

   Percent Null

   Lets you enter the estimated percentage of nulls used for columns if the option is available. Use whole numbers. You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

4. Click Close.

   Domain physical properties are defined and the Domain Editor closes.