orabase: Userenv Function

In Oracle/PLSQL, the userenv function can be used to retrieve information about the current Oracle session. Although this function still exists in Oracle for backwards compatibility, it is recommended that you use the sys_context function instead.

The syntax for the userenv function is:


       userenv( parameter )

parameter is the value to return from the current Oracle session. The possible values are:


CLIENT_INFO   Returns user session information stored using 
                          the DBMS_APPLICATION_INFO package
ENTRYID       Available auditing entry identifier
INSTANCE      The identifier number of the current instance
ISDBA         Returns TRUE if the user has DBA privileges. 
                          Otherwise, it will return FALSE.
LANG          The ISO abbreviation for the language
LANGUAGE      The language, territory, and character of 
                      the session in the following format:
                          Language_Territory.Characterset
SESSIONID     The identifier of the auditing session
TERMINAL      The OS identifier of the current session

Sample Values from my PC


SELECT UserEnv('CLIENT_INFO') FROM dual -- Returns NULL
SELECT UserEnv('ENTRYID') FROM dual     -- 0
SELECT UserEnv('INSTANCE') FROM dual    -- 1
SELECT UserEnv('ISDBA') FROM dual       -- FALSE
SELECT UserEnv('LANG') FROM dual        -- US
SELECT UserEnv('LANGUAGE') FROM dual    -- AMERICAN_AMERICA.UTF8
SELECT UserEnv('SESSIONID') FROM dual   -- 7297876
SELECT UserEnv('TERMINAL') FROM dual    -- pc-mydb

Source: http://www.techonthenet.com/oracle/functions/userenv.php