About Commonality in a CDB

In a multitenant container database (CDB), the basic principle of commonality is that a common phenomenon is the same in every existing and future container. In a CDB, "common" means "common to all containers." In contrast, a local phenomenon is restricted to exactly one existing container.

A corollary to the principle of commonality is that only a common user can alter the existence of common phenomena. More precisely, only a common user connected to the root can create, destroy, or modify CDB-wide attributes of a common user or role.