Oracle Internet Directory
Several times in this chapter, we’ve mentioned external directories. An external directory is a way to store information about a database, such as usernames and permissions. An external directory can relate to many different instances of Oracle across an enterprise. Oracle has its own external directory offering, the Oracle Internet Directory (OID). OID is a fully compliant LDAP (Lightweight Directory Access Protocol) directory. LDAP is a directory access protocol that was developed at the University of Michigan (Go Blue!).
With OID or other LDAP directories, you can create an authentication method that can span multiple databases, as well as be used for other purposes in your overall IT architecture. OID supports three types of authentication—anonymous, password based, and certificate based.
OID includes its own Replication Manager, for support of multiple directories, and a GUI interface tool.