Oracle Session Information From SYS_CONTEXT

SYS_CONTEXT is a standard Oracle Database function used to retrieve session-level information. SYS_CONTEXT  allow us to retrieve a set of session parameters via the namespace parameter ‘USERENV’.Basically, these are global variables that Oracle stores on the current session/user. Here is a sample of some session and user-specific information that can be obtained in one function call:

SQL> select sys_context('USERENV','AUTHENTICATION_TYPE') 
          ,sys_context('USERENV','CURRENT_SCHEMA') 
          ,sys_context('USERENV','CURRENT_SCHEMAID') 
          ,sys_context('USERENV','CURRENT_USER') 
          ,sys_context('USERENV','CURRENT_USERID') 
          ,sys_context('USERENV','DB_DOMAIN') 
          ,sys_context('USERENV','DB_NAME') 
          ,sys_context('USERENV','INSTANCE') 
         ,sys_context('USERENV','IP_ADDRESS') 
         ,sys_context('USERENV','ISDBA') 
         ,sys_context('USERENV','LANG') 
         ,sys_context('USERENV','LANGUAGE') 
         ,sys_context('USERENV','NETWORK_PROTOCOL') 
         ,sys_context('USERENV','NLS_CALENDAR') 
         ,sys_context('USERENV','NLS_CURRENCY') 
         ,sys_context('USERENV','NLS_DATE_FORMAT') 
        ,sys_context('USERENV','NLS_DATE_LANGUAGE') 
        ,sys_context('USERENV','NLS_TERRITORY') 
        ,sys_context('USERENV','OS_USER') 
        ,sys_context('USERENV','SESSION_USER') 
        ,sys_context('USERENV','SESSION_USERID') 
       ,sys_context('USERENV','SESSIONID') 
       ,sys_context('USERENV','TERMINAL') from dual ;

The output of the above sample is :

Enjoy      :-)