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Oracle/PLSQL: SYS_CONTEXT Function

Learn how to use the Oracle/PLSQL SYS_CONTEXT function with syntax and examples.

Description

The Oracle/PLSQL SYS_CONTEXT function can be used to retrieve information about the Oracle environment.

Syntax

The syntax for the Oracle/PLSQL SYS_CONTEXT function is:

SYS_CONTEXT( namespace, parameter, [ length ] )

Parameters or Arguments

namespace is an Oracle namespace that has already been created. If the namespace of 'USERENV' is used, attributes describing the current Oracle session can be returned.

parameter is a valid attribute that has been set using the DBMS_SESSION.set_context procedure.

length is optional. It is the length of the return value in bytes. If this parameter is omitted or if an invalid entry is provided, the sys_context function will default to 256 bytes.

Note

The valid parameters for the namespace called 'USERENV' are as follows: (Note that not all parameters are valid in all versions of Oracle)

Parameter Explanation Oracle 9i Oracle 10g Oracle 11g
ACTION Returns the position in the module No Yes Yes
AUDITED_CURSORID Returns the cursor ID of the SQL that triggered the audit Yes Yes Yes
AUTHENTICATED_IDENTITY Returns the identity used in authentication No Yes Yes
AUTHENTICATION_DATA Authentication data Yes Yes Yes
AUTHENTICATION_METHOD Returns the method of authentication No Yes Yes
AUTHENTICATION_TYPE Describes how the user was authenticated. Can be one of the following values: Database, OS, Network, or Proxy Yes No No
BG_JOB_ID If the session was established by an Oracle background process, this parameter will return the Job ID. Otherwise, it will return NULL. Yes Yes Yes
CLIENT_IDENTIFIER Returns the client identifier (global context) Yes Yes Yes
CLIENT_INFO User session information Yes Yes Yes
CURRENT_BIND Bind variables for fine-grained auditing No Yes Yes
CURRENT_SCHEMA Returns the default schema used in the current schema Yes Yes Yes
CURRENT_SCHEMAID Returns the identifier of the default schema used in the current schema Yes Yes Yes
CURRENT_SQL Returns the SQL that triggered the audit event Yes Yes Yes
CURRENT_SQL_LENGTH Returns the length of the current SQL statement that triggered the audit event No Yes Yes
CURRENT_USER Name of the current user Yes No No
CURRENT_USERID Userid of the current user Yes No No
DB_DOMAIN Domain of the database from the DB_DOMAIN initialization parameter Yes Yes Yes
DB_NAME Name of the database from the DB_NAME initialization parameter Yes Yes Yes
DB_UNIQUE_NAME Name of the database from the DB_UNIQUE_NAME initialization parameter No Yes Yes
ENTRYID Available auditing entry identifier Yes Yes Yes
ENTERPRISE_IDENTITY Returns the user's enterprise-wide identity No Yes Yes
EXTERNAL_NAME External of the database user Yes No No
FG_JOB_ID If the session was established by a client foreground process, this parameter will return the Job ID. Otherwise, it will return NULL. Yes Yes Yes
GLOBAL_CONTEXT_MEMORY The number used in the System Global Area by the globally accessed context Yes Yes Yes
GLOBAL_UID The global user ID from Oracle Internet Directory for enterprise security logins. Returns NULL for all other logins. No No Yes
HOST Name of the host machine from which the client has connected Yes Yes Yes
IDENTIFICATION_TYPE Returns the way the user's schema was created No Yes Yes
INSTANCE The identifier number of the current instance Yes Yes Yes
INSTANCE_NAME The name of the current instance No Yes Yes
IP_ADDRESS IP address of the machine from which the client has connected Yes Yes Yes
ISDBA Returns TRUE if the user has DBA privileges. Otherwise, it will return FALSE. Yes Yes Yes
LANG The ISO abbreviate for the language Yes Yes Yes
LANGUAGE The language, territory, and character of the session. In the following format:
language_territory.characterset
Yes Yes Yes
MODULE Returns the appplication name set through DBMS_APPLICATION_INFO package or OCI No Yes Yes
NETWORK_PROTOCOL Network protocol used Yes Yes Yes
NLS_CALENDAR The calendar of the current session Yes Yes Yes
NLS_CURRENCY The currency of the current session Yes Yes Yes
NLS_DATE_FORMAT The date format for the current session Yes Yes Yes
NLS_DATE_LANGUAGE The language used for dates Yes Yes Yes
NLS_SORT BINARY or the linguistic sort basis Yes Yes Yes
NLS_TERRITORY The territory of the current session Yes Yes Yes
OS_USER The OS username for the user logged in Yes Yes Yes
POLICY_INVOKER The invoker of row-level security policy functions No Yes Yes
PROXY_ENTERPRISE_IDENTITY The Oracle Internet Directory DN when the proxy user is an enterprise user No Yes Yes
PROXY_GLOBAL_UID The global user ID from Oracle Internet Directory for enterprise user security proxy users. Returns NULL for all other proxy users. No Yes Yes
PROXY_USER The name of the user who opened the current session on behalf of SESSION_USER Yes Yes Yes
PROXY_USERID The identifier of the user who opened the current session on behalf of SESSION_USER Yes Yes Yes
SERVER_HOST The host name of the machine where the instance is running No Yes Yes
SERVICE_NAME The name of the service that the session is connected to No Yes Yes
SESSION_USER The database user name of the user logged in Yes Yes Yes
SESSION_USERID The database identifier of the user logged in Yes Yes Yes
SESSIONID The identifier of the auditing session Yes Yes Yes
SID Session number No Yes Yes
STATEMENTID The auditing statement identifier No Yes Yes
TERMINAL The OS identifier of the current session Yes Yes Yes

Applies To

The SYS_CONTEXT function can be used in the following versions of Oracle/PLSQL:

  • Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i

Example

Let's look at some Oracle SYS_CONTEXT function examples and explore how to use the SYS_CONTEXT function in Oracle/PLSQL.

For example:

SYS_CONTEXT('USERENV', 'NLS_DATE_FORMAT')
Result: 'RR-MM-DD'

SYS_CONTEXT('USERENV', 'NLS_SORT')
Result: 'BINARY'