Comparison Options

The Comparison Options dialog box allows you to specify which types of objects you will compare. By default, all objects are selected for comparison.

The dialog box is divided into three panes:

Metaclasses – top-level objects such as tables, classes, entities, etc.
Attributes – simple properties associated with the selected metaclass.
Collections – properties that can contain multiple properties, and which are often sub-objects in their own right.

When you select a metaclass, the lists of attributes and collections change accordingly.

When you merge two models, differences are ignored for metaclasses, attributes and collections not selected for comparison. No changes will be applied to the model to be merged for a metaclass, attribute or collection where the selection checkmark has been cleared in the comparison options lists.

In the following illustration, the Entities collection check box is deselected for comparison:

Note: You can set your current selection of comparison options as default by clicking the Set as default button in the Comparison Options dialog box.

You can perform the following option selections:

You can...	To...
Select or deselect a metaclass check box	Select or deselect all its attributes and collections at once
Right-click a metaclass attribute or collection	Select or deselect the attribute or collection for all metaclasses at once from the contextual menu
Click the Select All or Deselect All tools	Select or deselect all metaclasses, attributes and collections at once

You can also select several metaclasses at the same time. Only attributes and collections that are common to all metaclasses are listed on the right hand side. When an attribute or collection property value is different from a selected metaclass to another, the attribute or collection check box is grayed-out to indicate the difference.

When you select a metaclass check box, you do not select the metaclass itself for comparison, but only its attributes and collections. If you want to select or deselect a metaclass for comparison, you have to click a Model and/or Package metaclass to display its corresponding attributes and collections and select or deselect the collection check box that corresponds to the unwanted metaclass in the list of Collections on the bottom right hand side.