Documentum provides robust versioning feature for almost all objects from dm_sysobject and its subtypes. Versioning allows updates, restore and tracking of documents in the repository when they are changed. This enables us to better manage the content as it is revised and even to restore a previous version for example, if we make a mistake in the current version. Versioning is especially helpful when several people work together on projects, or when information goes through several stages of development and review.
A new version of the object is created whenever we check in a document. All the versions of a particular object are stored in the vertical hierarchy. Each version tree has a numeric version label and optionally, one or more symbolic version label. By default when we check in a document, Documentum assigns CURRENT version label.
Version labels are used to uniquely identify a document in the version tree. Numeric version label and symbolic version labels are stored under r_version_label attribute of sysobject type. This attribute is a repeating attribute where the first value of repeating attributes stores numeric version label and subsequent values store symbolic version labels if any.
Symbolic versions labels are used to identify the document by specific words such as CURRENT, PENDING etc. Numeric version labels are assigned by Documentum by which we need to specify to override the existing document or create the document as major or minor version.
The following figure shows an example of version tree.
By default when we query for the documents, Documentum will bring up the documents with the version label CURRENT only. If we want to fetch all the versions of the document we need to add all keyword in the DQL.
For e.g., Select * from dm_document brings only the CURRENT version documents where as Select * from dm_document (all) brings documents of all versions.
Documentum uses i_chronicle_id attribute to identify its root document. Each versioned document will store the root document’s object ID in this property.