Connecting to Oracle DB with LDAP-Credentials
For special usernames, use double quotes.

SQL&gt; create user "USER@REALM.DOMAIN" identified by 1;

User created.

SQL&gt; grant create session to "USER@REALM.DOMAIN";

Grant succeeded.

SQL&gt; connect USER@REALM.DOMAIN/1
ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified


Warning: You are no longer connected to ORACLE.
SQL&gt; connect "USER@REALM.DOMAIN"/1
Connected.
SQL&gt;