We are using the Subversion to version the model generated out of SQL Developer Data Modeler. Like Erwin, is it possible to take a baseline of each changed version of the model as a single file? If not, how do we compare the latest version of the model with the previous one to find all the changes? Greatly appreciate if someone could please share the details if ever done like this before.
you can use "Versioning (or Team in v4)>Design Version History" in order to see all changes committed into repository. You can see changes (at object level) between revisions or compare (merge) to local version.
Otherwise you need to checkout versions of design at revisions you want to compare and can use "Tools>Compare/merge models" or "File>import>Data Modeler Design" in order to see all changes.