Oracle SYS_CONTEXT Function

Oracle SYS_CONTEXT Function Version 11.2

Oracle SYS_CONTEXT Function
Version 11.2

Actions As SYS
Note: USERENV is an Oracle provided namespace that describes the current session.
Syntax	SELECT sys_context('<namespace>', '<parameter>', <length>) FROM dual; SYS_CONTEXT(namespace IN VARCHAR2, attribute IN VARCHAR) RETURN VARCHAR; SYS_CONTEXT(namespace IN VARCHAR2, attribute IN VARCHAR, newoptional IN VARCHAR) RETURN VARCHAR;
Attribute	Return Value
ACTION	Identifies the position in the module (application name) and is set through the DBMS_APPLICATION_INFO package or OCI.
SELECT sys_context('USERENV', 'ACTION') FROM dual; exec dbms_application_info.set_action('INSERTING'); SELECT sys_context('USERENV', 'ACTION') FROM dual;
AUDITED_CURSORID	Returns the cursor ID of the SQL that triggered the audit. This parameter is not valid in a fine-grained auditing environment. If you specify it in such an environment, Oracle Database always returns NULL.
AUTHENTICATED_IDENTITY	Returns the identity used in authentication. In the list that follows, the type of user is followed by the value returned: Kerberos-authenticated enterprise user: kerberos principal name Kerberos-authenticated external user : kerberos principal name; same as the schema name SSL-authenticated enterprise user: the DN in the user's PKI certificate SSL-authenticated external user: the DN in the user's PKI certificate Password-authenticated enterprise user: nickname; same as the login name Password-authenticated database user: the database username; same as the schema name OS-authenticated external user: the external operating system user name Radius/DCE-authenticated external user: the schema name Proxy with DN : Oracle Internet Directory DN of the client Proxy with certificate: certificate DN of the client Proxy with username: database user name if client is a local database user; nickname if client is an enterprise user SYSDBA/SYSOPER using Password File: login name SYSDBA/SYSOPER using OS authentication: operating system user name
AUTHENTICATION_DATA	Data being used to authenticate the login user. For X.503 certificate authenticated sessions, this field returns the context of the certificate in HEX2 format. Note: You can change the return value of the   AUTHENTICATION_DATA attribute using the length parameter of the syntax. Values of up to 4000 are accepted. This is the only attribute of USERENV for which Oracle implements such a change.
AUTHENTICATION_METHOD	Returns the method of authentication. In the list that follows, the type of user is followed by the method returned. Password-authenticated enterprise user, local database user, or SYSDBA/SYSOPER using Password File; proxy with username using password: PASSWORD Kerberos-authenticated enterprise or external user: KERBEROS SSL-authenticated enterprise or external user: SSL Radius-authenticated external user: RADIUS OS-authenticated external user or SYSDBA/SYSOPER: OS DCE-authenticated external user: DCE Proxy with certificate, DN, or username without using password: NONE
BG_JOB_ID	Job ID of the current session if it was established by an Oracle background process. Null if the session was not established by a background process.
CLIENT_IDENTIFIER	Returns an identifier that is set by the application through the DBMS_SESSION.SET_IDENTIFIER procedure, the OCI attribute OCI_ATTR_CLIENT_IDENTIFIER, or the Java class Oracle.jdbc.OracleConnection.setClientIdentifier. This attribute is used by various database components to identify lightweight application users who authenticate as the same user.
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 user session information that can be stored by an application using the DBMS_APPLICATION_INFO package.
SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual; exec dbms_application_info.set_client_info('TEST'); SELECT sys_context('USERENV', 'CLIENT_INFO') FROM dual;
CURRENT_BIND	The bind variables for fine-grained auditing
CURRENT_EDITION_ID	The numeric identifier of the current edition
SELECT sys_context('USERENV', 'CURRENT_EDITION_ID') FROM dual;
CURRENT_EDITION_NAME	The name of the current edition
SELECT sys_context('USERENV', 'CURRENT_EDITION_NAME') FROM dual;
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.
SELECT sys_context('USERENV', 'CURRENT_SCHEMA') FROM dual;
CURRENT_SCHEMAID	Identifier of the default schema being used in the current session.
SELECT sys_context('USERENV', 'CURRENT_SCHEMAID') FROM dual; 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.
CURRENT_SQLn	CURRENT_SQLn attributes return subsequent 4K-byte increments, where n can be an integer from 1 to 7, inclusive. CURRENT_SQL1 returns bytes 4K to 8K; CURRENT_SQL2 returns bytes 8K to 12K, and so forth. You can specify these attributes only inside the event handler for the fine-grained auditing feature.
CURRENT_SQL_LENGTH	The length of the current SQL statement that triggers fine-grained audit or row-level security (RLS) policy functions or event handlers. Valid only inside the function or event handler.
CURRENT_USER	The name of the database user whose privileges are currently active.
SELECT sys_context('USERENV', 'CURRENT_USER') FROM dual;
CURRENT_USERID	The identifier of the database user whose privileges are currently active
SELECT sys_context('USERENV', 'CURRENT_USERID') FROM dual;
DATABASE_ROLE (new 11.2)	The database role is one of the following: PRIMARY, PHYSICAL STANDBY, LOGICAL STANDBY, SNAPSHOT STANDBY
SELECT sys_context('USERENV', 'DATABASE_ROLE') FROM dual;
DB_DOMAIN	Domain of the database as specified in the DB_DOMAIN initialization parameter.
SELECT sys_context('USERENV', 'DB_DOMAIN') FROM dual;
DB_NAME	Name of the database as specified in the DB_NAME initialization parameter.
SELECT sys_context('USERENV', 'DB_NAME') FROM dual; SELECT name, value FROM gv$parameter where name LIKE 'db%name';
DB_UNIQUE NAME	Name of the database as specified in the DB_UNIQUE_NAME initialization parameter.
SELECT sys_context('USERENV', 'DB_UNIQUE_NAME') FROM dual; SELECT name, value FROM gv$parameter where name LIKE 'db%name';
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.
ENTERPRISE_IDENTITY	Returns the user's enterprise-wide identity: For enterprise users: the Oracle Internet Directory DN. For external users: the external identity (Kerberos principal name, Radius and DCE schema names, OS user name, Certificate DN). For local users and SYSDBA/SYSOPER logins: NULL. The value of the attribute differs by proxy method: For a proxy with DN: the Oracle Internet Directory DN of the client For a proxy with certificate: the certificate DN of the client for external users; the Oracle Internet Directory DN for global users For a proxy with username: the Oracle Internet Directory DN if the client is an enterprise users; NULL if the client is a local database user.
FG_JOB_ID	Job ID of the current session if it was established by a client foreground process. Null if the session was not established by a foreground process.
GLOBAL_CONTEXT_MEMORY	The number used in the System Global Area by the globally accessed context.
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) logins; returns null for all other logins.
HOST	Name of the host machine from which the client has connected.
SELECT sys_context('USERENV', 'HOST') FROM dual;
IDENTIFICATION_TYPE	Returns the way the user's schema was created in the database. Specifically, it reflects the IDENTIFIED clause in the CREATE/ALTER USER syntax. In the list that follows, the syntax used during schema creation is followed by the identification type returned: IDENTIFIED BY password: LOCAL IDENTIFIED EXTERNALLY: EXTERNAL IDENTIFIED GLOBALLY: GLOBAL SHARED IDENTIFIED GLOBALLY AS DN: GLOBAL PRIVATE
SELECT sys_context('USERENV', 'IDENTIFICATION_TYPE') FROM dual;
INSTANCE	The instance identification number of the current instance.
SELECT sys_context('USERENV', 'INSTANCE') FROM dual;
INSTANCE_NAME	The name of the instance.
SELECT sys_context('USERENV', 'INSTANCE_NAME') FROM dual;
IP_ADDRESS	IP address of the machine from which the client is connected.
ISDBA	TRUE if the session is SYS
SELECT sys_context('USERENV', 'ISDBA') FROM dual;
LANG	The ISO abbreviation for the language name, a shorter form than the existing 'LANGUAGE' parameter.
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.
SELECT sys_context('USERENV', 'LANGUAGE') FROM dual;
MODULE	The application name (module) set through the DBMS_APPLICATION_INFO package or OCI.
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.
NLS_CALENDAR	The current calendar of the current session.
SELECT sys_context('USERENV', 'NLS_CALENDAR') FROM dual;
NLS_CURRENCY	The currency of the current session.
SELECT sys_context('USERENV', 'NLS_CURRENCY') FROM dual;
NLS_DATE_FORMAT	The date format for the session.
SELECT sys_context('USERENV', 'NLS_DATE_FORMAT') FROM dual;
NLS_DATE_LANGUAGE	The language used for expressing dates.
SELECT sys_context('USERENV', 'NLS_DATE_LANGUAGE') FROM dual;
NLS_SORT	BINARY or the linguistic sort basis.
SELECT sys_context('USERENV', 'NLS_SORT') FROM dual;
NLS_TERRITORY	The territory of the current session.
SELECT sys_context('USERENV', 'NLS_TERRITORY') FROM dual;
OS_USER	Operating system username of the client process that initiated the database session.
SELECT sys_context('USERENV', 'OS_USER') FROM dual;
POLICY_INVOKER	The invoker of row-level security (RLS) policy functions.
PROXY_ENTERPRISE_IDENTITY	Returns the Oracle Internet Directory DN when the proxy user is an enterprise user.
PROXY_GLOBAL_UID	Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) proxy users; returns NULL for all other proxy users.
PROXY_USER	Name of the database user who opened the current session on behalf of SESSION_USER.
PROXY_USERID	Identifier of the database user who opened the current session on behalf of SESSION_USER.
SERVER_HOST	The host name of the machine on which the instance is running.
SELECT sys_context('USERENV', 'SERVER_HOST') FROM dual;
SERVICE_NAME	The name of the service to which a given session is connected.
SELECT sys_context('USERENV', 'SERVICE_NAME') FROM dual;
SESSION_EDITION_NAME	The name of the current edition in the session
SELECT sys_context('USERENV', 'SESSION_EDITION_NAME') FROM dual;
SESSION_USER	Database user name by which the current user is authenticated. This value remains the same throughout the duration of the session.
SELECT sys_context('USERENV', 'SESSION_USER') FROM dual;
SESSION_USERID	Identifier of the database user name by which the current user is authenticated.
SELECT sys_context('USERENV', 'SESSION_USERID') FROM dual;
SESSIONID	The auditing session identifier. You cannot use this option in distributed SQL statements. This is the equivalent to the AUDSID column in gv$session.
SELECT sys_context('USERENV', 'SESSIONID') FROM dual;
SID	The session number (different from the session ID).
SELECT sys_context('USERENV', 'SID') FROM dual;
STATEMENTID	The auditing statement identifier. STATEMENTID represents the number of SQL statements audited in a given session.
TERMINAL	The operating system identifier for the client of the current session. In distributed SQL statements, this option returns the identifier for your local session. In a distributed environment, this is supported only for remote SELECT statements, not for remote INSERT, UPDATE, or DELETE operations. (The return length of this parameter may vary by operating system.)
SELECT sys_context('USERENV', 'TERMINAL') FROM dual;
Context Demo
User Created Contexts	CREATE OR REPLACE CONTEXT App_Ctx using My_pkg ACCESSED GLOBALLY; CREATE OR REPLACE PACKAGE my_pkg AUTHID DEFINER IS PROCEDURE set_session_id(p_session_id NUMBER); PROCEDURE set_ctx(p_name VARCHAR2, p_value VARCHAR2); PROCEDURE close_session(p_session_id NUMBER); END; / CREATE OR REPLACE PACKAGE BODY my_pkg IS  g_session_id NUMBER;  PROCEDURE set_session_id(p_session_id NUMBER) IS BEGIN   g_session_id := p_session_id;   dbms_session.set_identifier(p_session_id); end set_session_id; --=============================================== PROCEDURE set_ctx(p_name VARCHAR2, p_value VARCHAR2) IS BEGIN   dbms_session.set_context('App_Ctx',p_name,p_value,USER,g_session_id); END set_ctx; --=============================================== PROCEDURE close_session(p_session_id NUMBER) IS BEGIN   dbms_session.set_identifier(p_session_id);   dbms_session.clear_identifier; END close_session; --=============================================== END; / col var1 format a10 col var2 format a10 exec my_pkg.set_session_id(1234); exec my_pkg.set_ctx('Var1', 'Val1'); exec my_pkg.set_ctx('Var2', 'Val2'); SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual; -- Now we'll log out/log in -- At first, the context is empty-but we rejoin the session & there it is disconnect connect uwclass/uwclass SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual; exec my_pkg.set_session_id(1234); SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual; -- Now we'll show that this context is tied to our user (we specified -- USER above, if we used null anyone can join this session). grant execute on my_pkg to scott; conn scott/tiger exec uwclass.my_pkg.set_session_id(1234); SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual; -- Return to the set context again and clear it conn uwclass/uwclass exec my_pkg.set_session_id(1234); SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual; exec my_pkg.close_session(1234); SELECT sys_context('app_ctx', 'var1') var1, sys_context('app_ctx', 'var2') var2 FROM dual;
Another Demo	CREATE TABLE all_objs AS SELECT object_name FROM dba_objects; CREATE VIEW all_objs_view AS SELECT COUNT(*) obj_count FROM all_objs WHERE object_name = sys_context('UW_NAMESPACE', 'UW_PARAMETER'); CREATE OR REPLACE PROCEDURE set_param(valin IN VARCHAR2) AUTHID CURRENT_USER IS BEGIN   dbms_session.set_context('UW_NAMESPACE', 'UW_PARAMETER', valin); END; / CREATE CONTEXT uw_namespace USING set_param; exec SET_PARAM(valin => 'DBMS_SQL'); SELECT * FROM all_objs_view; exec set_param(valin => 'ZZZ'); SELECT * FROM all_objs_view;

  (From:http://www.morganslibrary.org/reference/sys_context.html)