Chapter 3 Building Physical Diagrams

Defining default physical options

Default physical options define physical options for all the objects in the model. The Default Physical Options dialog box has tabs corresponding to each type of object in the model.

DBMS definition file and default physical options

The default physical options are stored in the DBMS definition file. When you create a new model, you can choose to share the standard DBMS definition file or to create a copy of it. If you are sharing the DBMS definition file, then any changes that you make to the default physical options will be applied to all the models that share the definition.

For information on DBMS definition files, see the "Physical Data Model Basics" chapter.

Generating default values

The values you assign for default physical options can be included in a database creation script that you generate from a PDM, or can be directly generated in the target database via ODBC. You select the appropriate default physical options from the Selection page of the Database Generation dialog box.

You can view the script for a physical option in the Preview page for the object for which it is defined.

Physical option default values can also be reverse engineered from a database into a PDM.

To define default physical options:

1. Select Database→Default Physical Options to display the Default Physical Options dialog box. The Table page opens by default.
   
2. The Syntax page in the left pane lists the table options available and the right pane contains the physical options that have been selected for the object. You use the following tools to add physical options to, or remove them from, the current object:

   Tool	Action when clicked
   	Adds physical option selected in Syntax page (left pane) to Items page (right pane)
   	Aligns a selected physical option in the Items page with the corresponding physical option in the Syntax page
   	Removes physical option selected in Items page

Tool	Action when clicked
	Adds physical option selected in Syntax page (left pane) to Items page (right pane)
	Aligns a selected physical option in the Items page with the corresponding physical option in the Syntax page
	Removes physical option selected in Items page

1. To add an option for the object, select it from the list in the Syntax pane and click the Add tool to copy it to the Items pane. To add only a sub-parameter for the option, expand the option in the Syntax pane, select the required parameter and click the Add tool.
2. To set a value for a physical option parameter, select the parameter in the list in Items pane and enter or select the appropriate value in the field that appears below the pane. The entered value will then be displayed against the parameter in the Items list.
   
3. Repeat the above steps as many times as necessary to specified all your required physical options.
4. By default, the specified options will be applied to all the tables currently in the model and to all tables subsequently created. To apply the options to only some of the existing tables, click the Apply to button to display a selection dialog. Select the tables that you want to apply the options to from the list and then click OK.
5. Select the other tabs to specify physical options for other option types. (Note that the Apply to button is not available on the Database tab).
6. Click OK to close the Default Physical Options dialog box.

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