Delete Propagation

When you delete an object version or relationship, Microsoft® Repository sometimes automatically deletes other object versions and their attendant relationships. The automatic removal of an object version is called a propagated deletion. The process by which Repository first determines what propagated deletions are necessary and then performs those propagated deletions is called delete propagation.

Repository performs propagated deletions only when you remove a relationship whose corresponding origin collection type has the COLLECTION_PROPAGATEDELETE flag set. Such relationships are called delete-propagating relationships.

A single delete propagation can result in the removal of many object versions. There are several reasons for this:

• A to-be-removed delete-propagating relationship can have a TargetVersions collection containing many items.
  
  
• A to-be-removed object version can have many delete-propagating origin relationships.
  
  
• An object version to be removed automatically (that is, by propagated deletion) can itself have delete-propagating origin relationships.

Delete propagation can happen whenever you do any of these things:

• Delete a Delete-Propagating Origin Relationship.
  
  
• Delete a Delete-Propagating Destination Relationship.
  
  
• Remove an Item from the TargetVersions Collection of a Delete-Propagating Origin Relationship.
  
  
• Remove an Item from the TargetVersions Collection of a Delete-Propagating Destination Relationship.
  
  
• Delete an Object Version that Has Delete-Propagating Origin Relationships.