This Oracle tutorial explains how to use the Oracle/PLSQL SYS_CONTEXT function.
The Oracle/PLSQL SYS_CONTEXT function can be used to retrieve information about the Oracle environment.
The syntax for the Oracle/PLSQL SYS_CONTEXT function is:
SYS_CONTEXT( namespace, parameter, [ length ] )
namespace is an Oracle namespace. If the namespace of 'USERENV' is used, attributes describing the current Oracle session can be returned.
parameter is an attribute set with the DBMS_SESSION.set_context procedure.
length is optional. It is the length of the return value in bytes. Default to 256 bytes.
The valid parameters for the namespace called 'USERENV' are as follows:
| Parameter | Explanation |
|---|---|
| ACTION | Position in the module |
| AUDITED_CURSORID | Cursor ID of the SQL that triggered the audit |
| AUTHENTICATED_IDENTITY | Identity used in authentication |
| AUTHENTICATION_DATA | Authentication data |
| AUTHENTICATION_METHOD | method of authentication |
| AUTHENTICATION_TYPE | Describes how the user was authenticated:Database, OS, Network, or Proxy |
| 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. |
| CLIENT_IDENTIFIER | Returns the client identifier (global context) |
| CLIENT_INFO | User session information |
| CURRENT_BIND | Bind variables for fine-grained auditing |
| CURRENT_SCHEMA | Returns the default schema used in the current schema |
| CURRENT_SCHEMAID | Returns the identifier of the default schema used in the current schema |
| CURRENT_SQL | Returns the SQL that triggered the audit event |
| CURRENT_SQL_LENGTH | Returns the length of the current SQL statement that triggered the audit event |
| CURRENT_USER | Name of the current user |
| CURRENT_USERID | Userid of the current user |
| DB_DOMAIN | Domain of the database from the DB_DOMAIN initialization parameter |
| DB_NAME | Name of the database from the DB_NAME initialization parameter |
| DB_UNIQUE_NAME | Name of the database from the DB_UNIQUE_NAME initialization parameter |
| ENTRYID | Auditing entry identifier |
| ENTERPRISE_IDENTITY | User's enterprise-wide identity |
| EXTERNAL_NAME | External of the database user |
| FG_JOB_ID | Return the Job ID, if the session was established by a client foreground process. Otherwise, it will return NULL. |
| GLOBAL_CONTEXT_MEMORY | The number used in the System Global Area by the globally accessed context |
| GLOBAL_UID | Global user ID from Oracle Internet Directory for enterprise security logins. Returns NULL for all other logins. |
| HOST | Name of the host machine from which the client has connected |
| IDENTIFICATION_TYPE | The way the user's schema was created |
| INSTANCE | The identifier number of the current instance |
| INSTANCE_NAME | The name of the current instance |
| IP_ADDRESS | IP address of the machine from which the client has connected |
| ISDBA | Returns TRUE if the user has DBA privileges. Otherwise, it will return FALSE. |
| LANG | The ISO abbreviate for the language |
| LANGUAGE | The language, territory, and character of the session. In the following format: language_territory.characterset |
| MODULE | Returns the appplication name set through DBMS_APPLICATION_INFO package or OCI |
| NETWORK_PROTOCOL | Network protocol used |
| NLS_CALENDAR | The calendar of the current session |
| NLS_CURRENCY | The currency of the current session |
| NLS_DATE_FORMAT | The date format for the current session |
| NLS_DATE_LANGUAGE | The language used for dates |
| NLS_SORT | BINARY or the linguistic sort basis |
| NLS_TERRITORY | The territory of the current session |
| OS_USER | The OS username for the user logged in |
| POLICY_INVOKER | The invoker of row-level security policy functions |
| PROXY_ENTERPRISE_IDENTITY | The Oracle Internet Directory DN when the proxy user is an enterprise user |
| PROXY_GLOBAL_UID | The global user ID from Oracle Internet Directory for enterprise user security proxy users. Returns NULL for all other proxy users. |
| PROXY_USER | The name of the user who opened the current session on behalf of SESSION_USER |
| PROXY_USERID | The identifier of the user who opened the current session on behalf of SESSION_USER |
| SERVER_HOST | The host name of the machine where the instance is running |
| SERVICE_NAME | The name of the service that the session is connected to |
| SESSION_USER | The database user name of the user logged in |
| SESSION_USERID | The database identifier of the user logged in |
| SESSIONID | The identifier of the auditing session |
| SID | Session number |
| STATEMENTID | The auditing statement identifier |
| TERMINAL | The OS identifier of the current session |
SYS_CONTEXT('USERENV', 'NLS_DATE_FORMAT') ---------------------------------------- 'RR-MM-DD' SYS_CONTEXT('USERENV', 'NLS_SORT') --------------------------------- 'BINARY'