composite relationship

A composite relationship is a relationship between two geodatabase tables in which each feature in the destination table is expected to be related to an origin feature. In other words, any orphan destination features are considered a violation of the relationship. For example, a building and its mailbox must be related. While the building (origin) can exist on its own, a mailbox (destination) must be related to a building. When an origin feature is deleted, the destination feature should also be deleted. This is known as a cascade delete. Also see simple relationship.