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