Oracle database proxy login

[oracle@stormking DB11204 user]$ cat > proxy.login.demo.sql
set echo on
column proxy_user format a30
column session_user format a30

create user brian_proxy identified by zzxyz;
grant create session to brian_proxy;

create user brian_a identified by querty;
grant create session to brian_a;
alter user brian_a grant connect through brian_proxy;

create user brian_b identified by querty;
grant create session to brian_b;
alter user brian_b grant connect through brian_proxy;

conn brian_proxy[brian_a]/zzxyz
select
sys_context( 'userenv', 'session_user' ) session_user,
sys_context( 'userenv', 'proxy_user' ) proxy_user
from dual;

conn brian_proxy[brian_b]/zzxyz
select
sys_context( 'userenv', 'session_user' ) session_user,
sys_context( 'userenv', 'proxy_user' ) proxy_user
from dual;

quit
[oracle@stormking DB11204 user]$ sysdba @ proxy.login.demo.sql

SQL*Plus: Release 11.2.0.4.0 Production on Sat Jun 18 16:08:20 2016

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options

SQL> column proxy_user format a30
SQL> column session_user format a30

SQL> create user brian_proxy identified by zzxyz;

User created.

SQL> grant create session to brian_proxy;

Grant succeeded.

SQL>
SQL> create user brian_a identified by querty;

User created.

SQL> grant create session to brian_a;

Grant succeeded.

SQL> alter user brian_a grant connect through brian_proxy;

User altered.

SQL>
SQL> create user brian_b identified by querty;

User created.

SQL> grant create session to brian_b;

Grant succeeded.

SQL> alter user brian_b grant connect through brian_proxy;

User altered.

SQL>
SQL> conn brian_proxy[brian_a]/zzxyz
Connected.
SQL> select
  2  sys_context( 'userenv', 'session_user' ) session_user,
  3  sys_context( 'userenv', 'proxy_user' ) proxy_user
  4  from dual;

SESSION_USER                   PROXY_USER
------------------------------ ------------------------------
BRIAN_A                        BRIAN_PROXY

SQL>
SQL> conn brian_proxy[brian_b]/zzxyz
Connected.
SQL> select
  2  sys_context( 'userenv', 'session_user' ) session_user,
  3  sys_context( 'userenv', 'proxy_user' ) proxy_user
  4  from dual;

SESSION_USER                   PROXY_USER
------------------------------ ------------------------------
BRIAN_B                        BRIAN_PROXY