Composite differences between versions of a model

A composite difference is the aggregate of several individual but related changes between versions of a model. If you perform one action that creates multiple differences or conflicts, the result can appear as a single change, which is known as a composite difference.

For example, if you change the position of an element in a diagram, you create two changes: one for the X property and one for the Y property of the diagram element. Instead of displaying the X and Y changes as two differences, the changes are grouped together and displayed as a single difference. This grouping reduces the number of differences that you need to examine and makes it easier for you to analyze the origin of each difference.

When you compare or merge versions of a model, you can view composite differences in Model View and Diagram View. Model View lists composite differences hierarchically. Diagram View lists diagram composite differences.

The following actions commonly create composite differences:
  • Adding an association between two classes or entities, which creates up to six differences
  • For models other than data models: Applying a pattern to a portion of a model, which creates several differences
  • Dragging multiple elements in a diagram creates a multi-drag composite, which contains composites for every element that you dragged, which contain two differences for each positional change