Oracle PL/SQL Tutorial/System Tables Data Dictionary/role sys privs

Query role_sys_privs for privilege name

SQL>
SQL> SELECT *
  2  FROM   role_sys_privs
  3  WHERE  privilege = "CREATE SESSION"
  4  and    rownum < 50;
ROLE                           PRIVILEGE                                ADM
------------------------------ ---------------------------------------- ---
DBA                            CREATE SESSION                           YES
SQL>
SQL>