Relationships and Domains › Domains and Data Modeling › Domains in the Physical Model › Specifying Database-Specific Options For a Domain › Define Informix Domain Properties

Define Informix Domain Properties

In a model based on an Informix target server, you use the Informix tab in the Domain Editor to manage the data type, null option, and other properties for the selected domain.

Note: The options described here are the basic options available for most physical data types. There can be more options available depending on the physical data type you assign to the domain. We recommend that you refer to your Informix documentation for more information about using these properties.

To specify Informix domain 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 Informix 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.

   In

   Lets you enter the name of the Informix blobspace in which you want to store the current column. If you leave the text box blank, data in the current column is stored with the rest of the table.

4. Click Close.

   Domain properties are defined and the Domain Editor closes.