Oracle SYS_CONTEXT Functions
Versions 9.2 - 19.4

Security Advisory
The SYS_CONTEXT functions, to the best of our knowledge do not contain any ability to compromise the integrity of an Oracle Database but they can be an invaluable aid in securing one.

Think of these functions as a toolkit to be utilized in system and DDL BEFORE triggers for verifying identity and privileges before allowing actions and, in AFTER TRIGGERS for logging what happened, who did it, when, and where.
 
Recommended Security Rules

 NEVER
  • Write a PL/SQL function, package, or procedure without utilizing SYS_CONTEXT functions in the exception handlers
  • Allow anyone to execute a System statement without a BEFORE SYSTEM Trigger verifying the appropriateness of the action
  • Allow anyone to execute a potentially dangerous DDL without a BEFORE DDL Trigger verifying the appropriateness of the action
 WITH GREAT CARE
  • Verify trigger exception handlers so that they do not create an unnecessary outage
 CAUTIONS
  • When utilizing SYS_CONTEXT to enhance security do not just use a single function. Utilize them in the form of conditional logic verifying multiple parameters before they either allow the activity or raise an exception.
 
How Oracle Works
This code sample demonstrates using an AFTER DDL trigger to log the event when users connect to the application as proxy users CREATE OR REPLACE TRIGGER ddl_trig
AFTER DDL
ON DATABASE
BEGIN
  INSERT INTO activity_logs.ddl_log
  (current_schema,
   current_user,
   proxy_user,
   authenticated_by,
   ddl_date,
   ddl_type,
   object_type,
   object_owner,
   object_name)
  VALUES
  (sys_context('USERENV', 'CURRENT_SCHEMA'),
   sys_context('USERENV', 'CURRENT_USER'),
   sys_context('USERENV', 'PROXY_USER'),
   sys_context('USERENV', 'AUTHENTICATION_METHOD'),
   SYSTIMESTAMP,
   ora_sysevent,
   ora_dict_obj_type,
   ora_dict_obj_owner,
   ora_dict_obj_name);
END ddl_trig;
/
This code sample demonstrates use in an Exception handler of both SYS_CONTEXT functions and System Event Functions CREATE OR REPLACE PROCEDURE error_trap AUTHID CURRENT_USER IS
 odbname   v$database.name%TYPE;          -- Database name
 oinst     v$instance.instance_name%TYPE; -- Instance number
 enum      NUMBER;                        -- Error Message number
 emsg      VARCHAR2(250);                 -- Error text

 PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
  enum := sqlcode;
  emsg := sqlerrm;

  odbname := ora_database_name;
  oinst := ora_instance_num;

  INSERT INTO error_log
  (error_timestamp, database_name, instance_number,
   error_number, error_message, logged_on_as,
   client_host, service_name)
  VALUES
  (SYSTIMESTAMP, odbname, oinst, enum, emsg,
   sys_context('USERENV', 'CURRENT_SCHEMA'),
   sys_context('USERENV', 'HOST'),
   sys_context('USERENV', 'SERVICE_NAME'));
  COMMIT;
END error_trap;
/
 
SYS_CONTEXT Function Syntax and Demos
Data Dictionary Objects
DBA_EDITION V$PARAMETER V$SESSION
V$DATABASE    
Syntax SELECT sys_context('<namespace>', '<parameter>', <length>)
FROM dual;

SYS_CONTEXT(namespace IN VARCHAR2, attribute IN VARCHAR2)
RETURN VARCHAR;

SYS_CONTEXT(namespace IN VARCHAR2, attribute IN VARCHAR2, newoptional IN VARCHAR2)
RETURN VARCHAR2;
 
ACTION
Retrieves the value for the current session from v$session.action SYS_CONTEXT('USERENV', 'ACTION')
SELECT sys_context('USERENV', 'ACTION') FROM dual;

exec dbms_application_info.set_action('INSERTING');

SELECT sys_context('USERENV', 'ACTION') FROM dual;
 
APPLICATION_NAME
Retrieves the name of the application installed in the current application container SYS_CONTEXT('USERENV', 'APPLICATION_NAME')
SELECT sys_context('USERENV', 'APPLICATION_NAME') FROM dual;
 
AUDITED_CURSORID
Returns the cursor ID of the SQL that triggered the audit. Will return NULL with FGA. SYS_CONTEXT('USERENV', 'AUDITED_CURSORID')
SELECT sys_context('USERENV', 'AUDITED_CURSORID') FROM dual;
 
AUTHENTICATED_IDENTITY
Returns the identity used in logon authentication SYS_CONTEXT('USERENV', 'AUTHENTICATED_IDENTITY')
SELECT sys_context('USERENV', 'AUTHENTICATED_IDENTITY') FROM dual;

SYS_CONTEXT('USERENV','AUTHENTICATED_IDENTITY')
-----------------------------------------------
uwclass
 
AUTHENTICATION_DATA
Data being used to authenticate the login user. For X.503 sessions, returns the context of the certificate in HEX2 format. SYS_CONTEXT('USERENV', 'AUTHENTICATION_DATA')
SELECT sys_context('USERENV', 'AUTHENTICATION_DATA') FROM dual;
 
AUTHENTICATION_METHOD
Returns the method of authentication SYS_CONTEXT('USERENV', 'AUTHENTICATION_METHOD')
SELECT sys_context('USERENV', 'AUTHENTICATION_METHOD') FROM dual;

SYS_CONTEXT('USERENV','AUTHENTICATION_METHOD')
----------------------------------------------
PASSWORD
 
BG_JOB_ID
Job ID of the current session if it was established by an Oracle background process, else NULL SYS_CONTEXT('USERENV', 'BG_JOB_ID')
SELECT sys_context('USERENV', 'BG_JOB_ID') FROM dual;
 
CDB_NAME
Name of the container database SYS_CONTEXT('USERENV', 'CDB_NAME')
SELECT sys_context('USERENV', 'CDB_NAME') FROM dual;

SYS_CONTEXT('USERENV','CDB_NAME')
---------------------------------------------------------
orabeta
 
CLIENT_IDENTIFIER
Returns an identifier set by DBMS_SESSION.SET_IDENTIFIER. Can be used by to identify lightweight application users who authenticate as the same user. SYS_CONTEXT('USERENV', 'CLIENT_IDENTIFIER')
SELECT sys_context('USERENV', 'CLIENT_IDENTIFIER') FROM dual;

exec dbms_session.set_identifier(USER || ' ' || SYSTIMESTAMP);

SELECT sys_context('USERENV', 'CLIENT_IDENTIFIER') FROM dual;
 
CLIENT_INFO
Returns the value from v$session.client_info that can bet set using DBMS_APPLICATION_INFO SYS_CONTEXT('USERENV', 'CLIENT_INFO')
SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual;

exec dbms_application_info.set_client_info('TEST');

SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual;
 
CLIENT_PROGRAM_NAME
Name of the program used for the database session SYS_CONTEXT('USERENV', 'CLIENT_PROGRAM_NAME')
-- connect to root db
conn / as sysdba

SELECT sys_context('USERENV', 'CLIENT_PROGRAM_NAME') FROM dual;

SYS_CONTEXT('USERENV','CLIENT_PROGRAM_NAME')
---------------------------------------------
sqlplus.exe
 
CON_ID
Container Identifier SYS_CONTEXT('USERENV', 'CON_ID')
-- connect to root db
conn / as sysdba

SELECT sys_context('USERENV', 'CON_ID') FROM dual;

SYS_CONTEXT('USERENV','CON_ID')
-------------------------------
1
 
CON_NAME
Container name SYS_CONTEXT('USERENV', 'CON_NAME')
-- connect to root db
conn / as sysdba

SELECT sys_context('USERENV', 'CON_NAME') FROM dual;

SYS_CONTEXT('USERENV','CON_NAME')
---------------------------------
CDB$ROOT

-- connect to pluggable database
conn uwclass/uwclass@orabase

SYS_CONTEXT('USERENV','CON_NAME')
---------------------------------
ORABASE
 
CURRENT_BIND
The bind variables for fine-grained auditing SYS_CONTEXT('USERENV', 'CURRENT_BIND')
TBD
 
CURRENT_EDITION_ID
The numeric identifier of the current edition SYS_CONTEXT('USERENV', 'CURRENT_EDITION_ID')
SELECT sys_context('USERENV', 'CURRENT_EDITION_ID') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_EDITION_ID')
--------------------------------------------
131
 
CURRENT_EDITION_NAME
The name of the current edition SYS_CONTEXT('USERENV', 'CURRENT_EDITION_NAME')
SELECT sys_context('USERENV', 'CURRENT_EDITION_NAME') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_EDITION_NAME')
---------------------------------------------
ORA$BASE
 
CURRENT_SCHEMA
Name of the default schema being used in the current schema. This value can be changed during the session with an ALTER SESSION SET CURRENT_SCHEMA statement. SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA')
SELECT sys_context('USERENV', 'CURRENT_SCHEMA') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_SCHEMA')
---------------------------------------
UWCLASS
 
CURRENT_SCHEMAID
Identifier of the default schema being used in the current session SYS_CONTEXT('USERENV', 'CURRENT_SCHEMAID')
SELECT sys_context('USERENV', 'CURRENT_SCHEMAID') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_SCHEMAID')
-----------------------------------------
102

SELECT user#
FROM sys.user$
WHERE name = USER;
 
CURRENT_SQL
Returns the first 4K bytes of the current SQL that triggered the fine-grained auditing event SYS_CONTEXT('USERENV', 'CURRENT_SQL')
TBD
 
CURRENT_SQLn
CURRENT_SQLn attributes return subsequent 4K-byte increments, where n can be an integer from 1 to 7, inclusive SYS_CONTEXT('USERENV', 'CURRENT_SQLn')
TBD
 
CURRENT_SQL_LENGTH
The length of the current SQL that triggers fine-grained audit or row-level security (RLS) policy functions or event handlers where it is located SYS_CONTEXT('USERENV', 'CURRENT_SQL_LENGTH')
TBD
 
CURRENT_USER
The name of the database user whose privileges are currently active SYS_CONTEXT('USERENV', 'CURRENT_USER')
SELECT sys_context('USERENV', 'CURRENT_USER') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_USER')
-------------------------------------
UWCLASS
 
CURRENT_USERID
The identifier of the database user whose privileges are currently active SYS_CONTEXT('USERENV', 'CURRENT_USERID')
SELECT sys_context('USERENV', 'CURRENT_USERID') FROM dual;

SYS_CONTEXT('USERENV','CURRENT_USERID')
---------------------------------------
102
 
DATABASE_ROLE
The database role is one of the following: PRIMARY, PHYSICAL STANDBY, LOGICAL STANDBY, SNAPSHOT STANDBY SYS_CONTEXT('USERENV', 'DATABASE_ROLE')
SELECT sys_context('USERENV', 'DATABASE_ROLE') FROM dual;

SYS_CONTEXT('USERENV','DATABASE_ROLE')
--------------------------------------
PRIMARY
 
DB_DOMAIN
Domain of the database as specified in the DB_DOMAIN initialization parameter SYS_CONTEXT('USERENV', 'DB_DOMAIN')
SELECT sys_context('USERENV', 'DB_DOMAIN') FROM dual;
 
DB_NAME
Name of the database as specified in the DB_NAME initialization parameter. SYS_CONTEXT('USERENV', 'DB_NAME')
SELECT sys_context('USERENV', 'DB_NAME') FROM dual;

SYS_CONTEXT('USERENV','DB_NAME')
--------------------------------
orabeta

SELECT name, value
FROM gv$parameter
where name LIKE 'db%name';
 
DB_SUPPLEMENTAL_LOG_LEVEL
If supplemental logging is enabled, returns a string containing the list of enabled supplemental logging levels. Possible values are: ALL_COLUMN, FOREIGN_KEY, MINIMAL, PRIMARY_KEY, PROCEDURAL, and UNIQUE_INDEX: Else NULL SYS_CONTEXT('USERENV', 'CON_ID')
-- connect to root db
conn / as sysdba

SELECT sys_context('USERENV', 'DB_SUPPLEMENTAL_LOG_LEVEL')
FROM dual;

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

SELECT sys_context('USERENV', 'DB_SUPPLEMENTAL_LOG_LEVEL')
FROM dual;

SYS_CONTEXT('USERENV','DB_SUPPLEMENTAL_LOG_LEVEL')
--------------------------------------------------
MINIMAL
 
DB_UNIQUE_NAME
Name of the database as specified in the DB_UNIQUE_NAME initialization parameter SYS_CONTEXT('USERENV', 'DB_UNIQUE_NAME')
SELECT sys_context('USERENV', 'DB_UNIQUE_NAME') FROM dual;

SYS_CONTEXT('USERENV','DB_UNIQUE_NAME')
---------------------------------------
orabeta

SELECT name, value
FROM v$parameter
where name LIKE 'db%name';
 
DBLINK_INFO
Returns the source of a DB_LINK session SYS_CONTEXT('USERENV', 'DBLINK_INFO')
SELECT sys_context('USERENV', 'DBLINK_INFO') FROM dual;
 
ENTRYID
The available auditing entry identifier. You cannot use this option in distributed SQL statements. To use this keyword in USERENV, the initialization parameter AUDIT_TRAIL must be set to true. SYS_CONTEXT('USERENV', 'ENTRYID')
SELECT sys_context('USERENV', 'ENTRYID') FROM dual;
 
ENTERPRISE_IDENTITY
Returns the user's enterprise-wide identity SYS_CONTEXT('USERENV', 'ENTERPRISE_IDENTITY')
SELECT sys_context('USERENV', 'ENTERPRISE_IDENTITY') FROM dual;
 
EXTERNAL_NAME
Returns the workstation and workstation user name SYS_CONTEXT('USERENV', 'EXTERNAL_NAME')
conn uwclass/uwclass@pdbdev

SELECT sys_context('USERENV', 'EXTERNAL_NAME') FROM dual;

SYS_CONTEXT('USERENV','EXTERNAL_NAME')
---------------------------------------
PERRITO5\oracle
 
FG_JOB_ID
Job ID of the current session if it was established by a client foreground process else NULL SYS_CONTEXT('USERENV', 'FG_JOB_ID')
SELECT sys_context('USERENV', 'FG_JOB_ID') FROM dual;
 
GLOBAL_CONTEXT_MEMORY
The number used in the System Global Area by the globally accessed context SYS_CONTEXT('USERENV', 'GLOBAL_CONTEXT_MEMORY')
SELECT sys_context('USERENV', 'GLOBAL_CONTEXT_MEMORY') FROM dual;
 
GLOBAL_UID
Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) login: Else NULL SYS_CONTEXT('USERENV', 'GLOBAL_UID')
SELECT sys_context('USERENV', 'GLOBAL_UID') FROM dual;
 
HOST
Name of the host machine from which the client has connected SYS_CONTEXT('USERENV', 'HOST')
SELECT sys_context('USERENV', 'HOST') FROM dual;

SYS_CONTEXT('USERENV','HOST')
-----------------------------
WORKGROUP\PERRITO4
 
IDENTIFICATION_TYPE
Returns the way the user's schema was created in the database. Specifically, the IDENTIFIED clause of the CREATE/ALTER USER DDL SYS_CONTEXT('USERENV', 'IDENTIFICATION_TYPE')
SELECT sys_context('USERENV', 'IDENTIFICATION_TYPE') FROM dual;
 
INSTANCE
The instance identification number of the instance to which the session is connected SYS_CONTEXT('USERENV', 'INSTANCE')
SELECT sys_context('USERENV', 'INSTANCE') FROM dual;
 
INSTANCE_NAME
The name of the instance to which the session is connected SYS_CONTEXT('USERENV', 'INSTANCE_NAME')
SELECT sys_context('USERENV', 'INSTANCE_NAME') FROM dual;
 
IP_ADDRESS
IP address of the NIC from which the client is connected SYS_CONTEXT('USERENV', 'IP_ADDRESS')
SELECT sys_context('USERENV', 'IP_ADDRESS') FROM dual;

SYS_CONTEXT('USERENV', 'IP_ADDRESS')
------------------------------------------------
141.204.244.96
 
IS_APPLY_SERVER
Returns TRUE if queried from within a SQL Apply server in a logical standby database. Otherwise, returns FALSE SYS_CONTEXT('USERENV', 'IS_APPLY_SERVER')
SELECT sys_context('USERENV', 'IS_APPLY_SERVER')
FROM dual;

SYS_CONTEXT('USERENV','IS_APPLY_SERVER')
----------------------------------------
FALSE
 
IS_DG_ROLLING_UPGRADE
Returns TRUE if a rolling upgrade of the database software in a Data Guard configuration, initiated by way of the DBMS_ROLLING package, is active. Otherwise, returns FALSE. SYS_CONTEXT('USERENV', 'IS_DG_ROLLING_UPGRADE')
SELECT sys_context('USERENV', 'IS_DG_ROLLING_UPGRADE')
FROM dual;

SYS_CONTEXT('USERENV','IS_DG_ROLLING_UPGRADE')
----------------------------------------------
FALSE
 
ISDBA
TRUE if the session is SYS SYS_CONTEXT('USERENV', 'ISDBA')
SELECT sys_context('USERENV', 'ISDBA') FROM dual;
 
LANG
The ISO abbreviation for the language name, a shorter form than the existing 'LANGUAGE' parameter. SYS_CONTEXT('USERENV', 'LANG')
SELECT sys_context('USERENV', 'LANG') FROM dual;
 
LANGUAGE
The language and territory currently used by your session, along with the database character set, in the form:
language_territory.characterset.		 SYS_CONTEXT('USERENV', 'LANGUAGE')
SELECT sys_context('USERENV', 'LANGUAGE') FROM dual;
 
LDAP_SERVER_TYPE
Returns the configured LDAP server type, one of OID, AD(Active Directory), OID_G, or OPENLDAP SYS_CONTEXT('USERENV', 'LDAP_SERVER_TYPE')
SELECT sys_context('USERENV', 'LDAP_SERVER_TYPE') FROM dual;
 
MODULE
The application name (module) set through DBMS_APPLICATION_INFO SYS_CONTEXT('USERENV', 'MODULE')
SELECT sys_context('USERENV', 'MODULE') FROM dual;
 
NETWORK_PROTOCOL
Network protocol being used for communication, as specified in the 'PROTOCOL=protocol' portion of the connect string SYS_CONTEXT('USERENV', 'NETWORK_PROTOCOL')
SELECT sys_context('USERENV', 'NETWORK_PROTOCOL') FROM dual;

SYS_CONTEXT('USERENV', 'NETWORK_PROTOCOL')
------------------------------------------------
tcp
 
NLS_CALENDAR
The current calendar of the current session SYS_CONTEXT('USERENV', 'NLS_CALENDAR')
SELECT sys_context('USERENV', 'NLS_CALENDAR') FROM dual;

SYS_CONTEXT('USERENV','NLS_CALENDAR')
-------------------------------------
GREGORIAN
 
NLS_CURRENCY
The currency of the current session SYS_CONTEXT('USERENV', 'NLS_CURRENCY')
SELECT sys_context('USERENV', 'NLS_CURRENCY') FROM dual;

SYS_CONTEXT('USERENV','NLS_CURRENCY')
-------------------------------------
$
 
NLS_DATE_FORMAT
The date format for the session SYS_CONTEXT('USERENV', 'NLS_DATE_FORMAT')
SELECT sys_context('USERENV', 'NLS_DATE_FORMAT') FROM dual;

SYS_CONTEXT('USERENV','NLS_DATE_FORMAT')
----------------------------------------
DD-MON-YYYY HH24:MI:SS
 
NLS_DATE_LANGUAGE
The language used for expressing dates SYS_CONTEXT('USERENV', 'NLS_LANGUAGE')
SELECT sys_context('USERENV', 'NLS_DATE_LANGUAGE') FROM dual;

SYS_CONTEXT('USERENV','NLS_DATE_LANGUAGE')
------------------------------------------
AMERICAN
 
NLS_SORT
BINARY or the linguistic sort basis SYS_CONTEXT('USERENV', 'NLS_SORT')
SELECT sys_context('USERENV', 'NLS_SORT') FROM dual;

SYS_CONTEXT('USERENV','NLS_SORT')
---------------------------------
BINARY
 
NLS_TERRITORY
The territory of the current session SYS_CONTEXT('USERENV', 'NLS_TERRITORY')
SELECT sys_context('USERENV', 'NLS_TERRITORY') FROM dual;

SYS_CONTEXT('USERENV','NLS_TERRITORY')
--------------------------------------
AMERICA
 
ORACLE_HOME
Returns the value of $ORACLE_HOME SYS_CONTEXT('USERENV', 'ORACLE_HOME')
SELECT sys_context('USERENV', 'ORACLE_HOME')
FROM dual;

SYS_CONTEXT('USERENV','ORACLE_HOME')
-------------------------------------
/u01/app/oracle/product/18.1.0/dbhome_1
 
OS_USER
Operating system username of the client process that initiated the database session SYS_CONTEXT('USERENV', 'OS_USER')
SELECT sys_context('USERENV', 'OS_USER') FROM dual;

SYS_CONTEXT('USERENV','OS_USER')
--------------------------------
perrito4\oracle
 
PLATFORM_SLASH
Returns the forward or back-slash for the operating system environment SYS_CONTEXT('USERENV', 'PLATFORM_SLASH')
SELECT sys_context('USERENV', 'PLATFORM_SLASH')
FROM dual;

SYS_CONTEXT('USERENV','PLATFORM_SLASH')
---------------------------------------
/
 
POLICY_INVOKER
The invoker of row-level security (RLS) policy functions SYS_CONTEXT('USERENV', 'POLICY_INVOKER')
SELECT sys_context('USERENV', 'POLICY_INVOKER') FROM dual;
 
PROXY_ENTERPRISE_IDENTITY
Returns the Oracle Internet Directory DN when the proxy user is an enterprise user SYS_CONTEXT('USERENV', 'PROXY_ENTERPRISE_IDENTITY')
TBD
 
PROXY_USER
Name of the database user who opened the current session on behalf of the SESSION_USER SYS_CONTEXT('USERENV', 'PROXY_USER')
conn dam42z[m12345]@oratest

SELECT sys_context('USERENV', 'PROXY_USER') FROM dual;

SYS_CONTEXT('USERENV', 'PROXY_USER')
------------------------------------------------
DM42Z
 
PROXY_USERID
Identifier of the database user who opened the current session on behalf of SESSION_USER SYS_CONTEXT('USERENV', 'PROXY_USERID')
conn dam42z[m12345]@oratest

SELECT sys_context('USERENV', 'PROXY_USERID') FROM dual;

SYS_CONTEXT('USERENV', 'PROXY_USERID')
------------------------------------------------
247
 
SCHEDULER_JOB
Returns Y if the current session belongs to a foreground job or background job. Otherwise, returns N. SYS_CONTEXT('USERENV', 'SCHEDULER_JOB')
SELECT sys_context('USERENV', 'SCHEDULER_JOB')
FROM dual;

SYS_CONTEXT('USERENV','SCHEDULER_JOB')
--------------------------------------
N
 
SERVER_HOST
The host name of the machine on which the instance is running SYS_CONTEXT('USERENV', 'SESSION_USER')
SELECT sys_context('USERENV', 'SERVER_HOST') FROM dual;

SYS_CONTEXT('USERENV','SERVER_HOST')
------------------------------------
perrito4
 
SERVICE_NAME
The name of the service to which a given session is connected SYS_CONTEXT('USERENV', 'SERVICE_NAME')
-- connect to the CDB
SQL> conn sys@orabase as sysdba
Enter password: *********
Connected.

SQL> SELECT sys_context('USERENV', 'SERVICE_NAME') FROM dual;

SYS_CONTEXT('USERENV','SERVICE_NAME')
-------------------------------------------------------------
orabeta

-- connect to a PDB
SQL> conn uwclass/uwclass@orabase
Connected.

SQL> SELECT sys_context('USERENV', 'SERVICE_NAME') FROM dual;

SYS_CONTEXT('USERENV','SERVICE_NAME')
-------------------------------------------------------------
orabase
 
SESSION_DEFAULT_COLLATION
The default collation for the session, which is set by the ALTER SESSION SET DEFAULT_COLLATION value. To run this the database must be configured for 12.2 or higher with MAX_STRING_SIZE = EXTENDED. SYS_CONTEXT('USERENV', 'SESSION_DEFAULT_COLLATION')
SELECT sys_context('USERENV', 'SESSION_DEFAULT_COLLATION') FROM dual;

SYS_CONTEXT('USERENV','SESSION_DEFAULT_COLLATION')
-------------------------------------------
NONE
 
SESSION_EDITION_ID
The id number of the current edition in the session SYS_CONTEXT('USERENV', 'SESSION_EDITION_ID')
SELECT sys_context('USERENV', 'SESSION_EDITION_ID') FROM dual;

SYS_CONTEXT('USERENV','SESSION_EDITION_ID')
-------------------------------------------
131
 
SESSION_EDITION_NAME
The name of the current edition in the session SYS_CONTEXT('USERENV', 'SESSION_EDITION_NAME')
SELECT sys_context('USERENV', 'SESSION_EDITION_NAME') FROM dual;

SYS_CONTEXT('USERENV', 'SESSION_EDITION_NAME')
---------------------------------------------
ORA$BASE
 
SESSION_USER
Database user name by which the current user is authenticated. Remains the same for the duration of the session. SYS_CONTEXT('USERENV', 'SESSION_USER')
SELECT sys_context('USERENV', 'SESSION_USER') FROM dual;

SYS_CONTEXT('USERENV','SESSION_USER')
-------------------------------------
UWCLASS
 
SESSION_USERID
Identifier of the database user name by which the current user is authenticated SYS_CONTEXT('USERENV', 'SESSION_USERID')
SELECT sys_context('USERENV', 'SESSION_USERID') FROM dual;

SYS_CONTEXT('USERENV','SESSION_USERID')
---------------------------------------
102
 
SESSIONID
The auditing session identifier. Cannot be used with distributed SQL statements: Equivalent to the AUDSID column in gv$session. SYS_CONTEXT('USERENV', 'SESSIONID')
SELECT sys_context('USERENV', 'SESSIONID') FROM dual;

SYS_CONTEXT('USERENV','SESSIONID')
----------------------------------
60074
 
SID
The session number (different from the session ID) SYS_CONTEXT('USERENV', 'SID')
SELECT sys_context('USERENV', 'SID') FROM dual;

SYS_CONTEXT('USERENV','SID')
----------------------------
10
 
STATEMENTID
The auditing statement identifier SYS_CONTEXT('USERENV', 'STATEMENTID')
TBD
 
SYS_SESSION_ROLES
This is a twist on the SYS_CONTEXT function as it does not use USERENV. With this usage SYS_CONTEXT queries the list of the user's current default roles and returns TRUE if the role is granted. SYS_CONTEXT('SYS_SESSION_ROLES', 'SUPERVISOR')
conn scott/tiger@pdbdev

SELECT sys_context('SYS_SESSION_ROLES', 'RESOURCE')
FROM dual;

SYS_CONTEXT('SYS_SESSION_ROLES','SUPERVISOR')
---------------------------------------------
FALSE

conn sys@pdbdev as sysdba

GRANT resource TO scott;

conn scott/tiger@pdbdev

SELECT sys_context('SYS_SESSION_ROLES', 'RESOURCE')
FROM dual;

SYS_CONTEXT('SYS_SESSION_ROLES','SUPERVISOR')
---------------------------------------------
TRUE
 
TERMINAL
The operating system identifier for the client of the current session SYS_CONTEXT('USERENV', 'TERMINAL')
SELECT sys_context('USERENV', 'TERMINAL') FROM dual;

SYS_CONTEXT('USERENV','TERMINAL')
---------------------------------
PERRITO4
 
UNIFIED_AUDIT_SESSIONID
If queried while connected to a database that uses unified auditing or mixed mode auditing, returns the unified audit session ID

If queried while connected to a database that uses traditional auditing, returns NULL		 SYS_CONTEXT('USERENV', 'UNIFIED_AUDIT_SESSIONID')
SELECT sys_context('USERENV', 'UNIFIED_AUDIT_SESSIONID') FROM dual;

SYS_CONTEXT('USERENV','UNIFIED_AUDIT_SESSIONID')
-------------------------------------------------
2134506887

Related Topics
DDL Event Triggers
Exception Handling
System Event Triggers
USERENV