What is an Application Context?
- Name. Refers to the name of the attribute set that is associated with the value. For example, if the empno_ctx application context retrieves an employee ID from the HR.EMPLOYEES table, it could have a name such as employee_id.
- Value. Refers to a value set by the attribute. For example, for the empno_ctx application context, if you wanted to retrieve an employee ID from the HR.EMPLOYEES table, you could create a value called emp_id that sets the value for this ID.
Types of Application Contexts
- Database session-based application contexts. This type retrieves data that is stored in the database user session (that is, the UGA) cache. There are three categories of database session-based application contexts:
- Initialized locally. Initializes the application context locally, to the session of the user.
- Initialized externally. Initializes the application context from an Oracle Call Interface (OCI) application, a job queue process, or a connected user database link.
- Initialized globally. Uses attributes and values from a centralized location, such as an LDAP directory.
- Global application contexts. This type retrieves data that is stored in the System Global Area (SGA) so that it can be used for applications that use a sessionless model, such as middle-tier applications in a three-tiered architecture. A global application context is useful if the session context must be shared across sessions, for example, through connection pool implementations.
- Client session-based application contexts. This type uses Oracle Call Interface functions on the client side to set the user session data, and then to perform the necessary security checks to restrict user access.
Database Session-Based Application Contexts
- If the value of the parameter in the namespace already has been set, then SET_CONTEXT overwrites this value.
- Be aware that any changes in the context value are reflected immediately and subsequent calls to access the value through the SYS_CONTEXT function will return the most recent value
Using SYS_CONTEXT with Database Links
Using DBMS_SESSION.SET_CONTEXT to Set Session Information
Identifies the position in the module (application name) and is set through the DBMS_APPLICATION_INFO package or OCI.
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, then Oracle Database always returns NULL.
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
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 Database implements such a change.
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 Background process (job queue slave process): JOB You can use IDENTIFICATION_TYPE to distinguish between external and enterprise users when the authentication method is Password, Kerberos, or SSL.
Job ID of the current session if it was established by an Oracle Database background process. Null if the session was not established by a background process.
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 database user.
Returns up to 64 bytes of user session information that can be stored by an application using the DBMS_APPLICATION_INFO package.
The bind variables for fine-grained auditing.
The identifier of the current edition.
The name of the current edition.
The name of the currently active default schema. This value may change during the duration of a session through use of an ALTER SESSION SET CURRENT_SCHEMA statement. This may also change during the duration of a session to reflect the owner of any active definer's rights object. When used directly in the body of a view definition, this returns the default schema used when executing the cursor that is using the view; it does not respect views used in the cursor as being definer's rights.
Note: Oracle recommends against issuing the SQL statement ALTER SESSION SET CURRENT_SCHEMA from within a stored PL/SQL unit.
Identifier of the currently active default schema.
CURRENT_SQL returns the first 4K bytes of the current SQL that triggered the fine-grained auditing event. The 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.
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.
The name of the database user whose privileges are currently active. This may change during the duration of a session to reflect the owner of any active definer's rights object. When no definer's rights object is active, CURRENT_USER returns the same value as SESSION_USER. When used directly in the body of a view definition, this returns the user that is executing the cursor that is using the view; it does not respect views used in the cursor as being definer's rights.
The identifier of the database user whose privileges are currently active.
The database role using the SYS_CONTEXT function with the USERENV namespace. The role is one of the following: PRIMARY, PHYSICAL STANDBY, LOGICAL STANDBY, SNAPSHOT STANDBY.
Domain of the database as specified in the DB_DOMAIN initialization parameter.
Name of the database as specified in the DB_NAME initialization parameter.
Name of the database as specified in the DB_UNIQUE_NAME initialization parameter.
The current audit entry number. The audit entryid sequence is shared between fine-grained audit records and regular audit records. You cannot use this attribute in distributed SQL statements. The correct auditing entry identifier can be seen only through an audit handler for standard or fine-grained audit.
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.
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.
Returns the number being used in the System Global Area by the globally accessed context.
Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) logins; returns null for all other logins.
Name of the host machine from which the client has connected.
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
The instance identification number of the current instance.
The name of the instance.
IP address of the machine from which the client is connected. If the client and server are on the same machine and the connection uses IPv6 addressing, then ::1 is returned.
Returns TRUE if the user has been authenticated as having DBA privileges either through the operating system or through a password file.
The abbreviated name for the language, a shorter form than the existing 'LANGUAGE' parameter.
The language and territory currently used by your session, along with the database character set, in this form:
The application name (module) set through the DBMS_APPLICATION_INFO package or OCI.
Network protocol being used for communication, as specified in the 'PROTOCOL=protocol' portion of the connect string.
The current calendar of the current session.
The currency of the current session.
The date format for the session.
The language used for expressing dates.
BINARY or the linguistic sort basis.
The territory of the current session.
Operating system user name of the client process that initiated the database session.
The invoker of row-level security (RLS) policy functions.
Returns the Oracle Internet Directory DN when the proxy user is an enterprise user.
Returns the global user ID from Oracle Internet Directory for Enterprise User Security (EUS) proxy users; returns NULL for all other proxy users.
Name of the database user who opened the current session on behalf of SESSION_USER.
Identifier of the database user who opened the current session on behalf of SESSION_USER.
The host name of the machine on which the instance is running.
The name of the service to which a given session is connected.
The identifier of the session edition.
The name of the session edition.
The name of the database user at logon. For enterprise users, returns the schema. For other users, returns the database user name. This value remains the same throughout the duration of the session.
The identifier of the database user at logon.
The auditing session identifier. You cannot use this attribute in distributed SQL statements.
The session ID.
The auditing statement identifier. STATEMENTID represents the number of SQL statements audited in a given session. You cannot use this attribute in distributed SQL statements. The correct auditing statement identifier can be seen only through an audit handler for standard or fine-grained audit.
The operating system identifier for the client of the current session. In distributed SQL statements, this attribute 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.)
Describes all context namespaces in the current session for which attributes and values were specified using the DBMS_SESSION.SET_CONTEXT procedure. It lists the namespace and its associated schema and PL/SQL package.
Describes the driving contexts defined for the synonyms, tables, and views accessible to the current user. (A driving context is a context used in a Virtual Private Database policy.)
Provides all context namespace information in the database. Its columns are the same as those in the ALL_CONTEXT view, except that it includes the TYPE column. The TYPE column describes how the application context is accessed or initialized.
Describes all driving contexts in the database that were added by the DBMS_RLS.ADD_POLICY_CONTEXT procedure. Its columns are the same as those in ALL_POLICY_CONTEXTS.
Describes the context attributes and their values set for the current session.
Describes the driving contexts defined for the synonyms, tables, and views owned by the current user. Its columns (except for OBJECT_OWNER) are the same as those in ALL_POLICY_CONTEXTS.
Lists set attributes in the current session. Users do not have access to this view unless you grant the user the SELECT privilege on it.
Lists detailed information about each current session. Users do not have access to this view unless you grant the user the SELECT privilege on it