A version is a snapshot of a document or model object at a given moment in time. Versions are created to keep track of changes during the lifetime of a document or object, and appear as a tree on the Versions tab of repository object property sheets. Details of the current version are displayed on the Version Info tab.
By default, and unlike many repository systems, the PowerDesigner repository does not create a new version of a document each time you check it in. To create a new version of a document you must specify that you want to freeze it. You can freeze documents during check in or check out, or directly in the repository.
All repository documents and model objects can be versioned, but repository folders, projects, users, and groups are not versioned. Versions other than the first or baseline version are stored as differences from the previous version. As a rule of thumb, the baseline version of a model stored in the repository takes twice the size as it does when saved as an XML file.
You cannot individually control the freezing and versioning of PowerDesigner model objects. Each changed object has its version frozen and version number increased by one each time you freeze its parent model's version.