System Session Variabels - OBIEE 11G

Session variables are similar to dynamic repository variables in that they obtain their values from initialization blocks. Unlike dynamic repository variables, however, the initialization of session variables is not scheduled. When a user begins a session, the Oracle BI Server creates new instances of session variables and initializes them.

Two types of session  variables:

•  System Session Variables
  
• Nonsystem Session Variables
  

Sytem Session Variables : 
System session variables are session variables that the Oracle BI Server and Oracle BI Presentation Services use for specific purposes. System session variables have reserved names that cannot be used for other kinds of variables (such as static or dynamic repository variables and nonsystem session variables).

When you use these variables for Oracle BI Presentation Services, preface their names with NQ_SESSION. For example, to filter a column on the value of the variable LOGLEVEL, set the filter to the variable NQ_SESSION.LOGLEVEL.

 

Variable	Description
USER	Holds the value the user enters as his or her logon name. This variable is typically populated from the LDAP profile of the user.
PROXY	Holds the name of the proxy user. A proxy user is a user that has been authorized to act for another user.
GROUP	Contains the groups to which the user belongs. Exists only for compatibility with previous releases. Legacy groups are mapped to application roles automatically.
WEBGROUPS	Specifies the Catalog groups (Presentation Services groups) to which the user belongs, if any. Note that the recommended practice is to use application roles rather than Catalog groups.
USERGUID	Contains the global unique identifier (GUID) of the user, typically populated from the LDAP profile of the user.
ROLES	Contains the application roles to which the user belongs.
ROLEGUIDS	Contains the global unique identifiers (GUIDs) for the application roles to which the user belongs. GUIDs for application roles are the same as the application role names.
PERMISSIONS	Contains the permissions held by the user, such as oracle.bi.server.impersonateUser or oracle.bi.server.manageRepository.
DISPLAYNAME	Used for Oracle BI Presentation Services. It contains the name that is displayed to the user in the greeting in the Oracle BI Presentation Services user interface. It is also saved as the author field for catalog objects. This variable is typically populated from the LDAP profile of the user.
PORTALPATH	Used for Oracle BI Presentation Services. It identifies the default dashboard the user sees when logging in (the user can override this preference after logged on).
LOGLEVEL	The value of LOGLEVEL (a number between 0 and 5) determines the logging level that the Oracle BI Server uses for user queries. This system session variable overrides a variable defined in the Users object in the Administration Tool. If the administrator user (defined upon install) has a Logging level defined as 4 and the session variable LOGLEVEL defined in the repository has a value of 0 (zero), the value of 0 applies.
REQUESTKEY	Used for Oracle BI Presentation Services. Any users with the same nonblank request key share the same Oracle BI Presentation Services cache entries. This tells Oracle BI Presentation Services that these users have identical content filters and security in the Oracle BI Server. Sharing Oracle BI Presentation Services cache entries is a way to minimize unnecessary communication with the Oracle BI Server.
SKIN	Determines certain elements of the look and feel of the Oracle BI Presentation Services user interface. The user can alter some elements of the user interface by picking a style when logged on to Oracle BI Presentation Services. The SKIN variable points to an Oracle BI Presentation Services folder that contains the nonalterable elements (for example, figures such as GIF files). Such directories begin with sk_. For example, if a folder were called sk_companyx, the SKIN variable would be set to companyx.
DESCRIPTION	Contains a description of the user, typically populated from the LDAP profile of the user.
USERLOCALE	Contains the locale of the user, typically populated from the LDAP profile of the user.
DISABLE_CACHE_HIT	Used to enable or disable Oracle BI Server result cache hits. This variable has a possible value of 0 or 1.
DISABLE_CACHE_SEED	Used to enable or disable Oracle BI Server result cache seeding. This variable has a possible value of 0 or 1.
DISABLE_SUBREQUEST_CACHE	Used to enable or disable Oracle BI Server subrequest cache hits and seeding. This variable has a possible value of 0 or 1.
SELECT_PHYSICAL	Identifies the query as a SELECT_PHYSICAL query..
DISABLE_PLAN_CACHE_HIT	Used to enable or disable Oracle BI Server plan cache hits. This variable has a possible value of 0 or 1.
DISABLE_PLAN_CACHE_SEED	Used to enable or disable Oracle BI Server plan cache seeding. This variable has a possible value of 0 or 1.
TIMEZONE	Contains the time zone of the user, typically populated from the LDAP profile of the user.

The SELECT_PHYSICAL command provides the functionality to directly query objects in the Physical layer of the metadata repository, and to nest such a statement within a query against the Business Model and Mapping layer or the Presentation layer.

Syntax for the SELECT_PHYSICAL Statement

Basic syntax for SELECT_PHYSICAL queries is equivalent to  basic syntax of select statement  with the term

SELECT_PHYSICAL replacing the word SELECT, namely:

SELECT_PHYSICAL [DISTINCT] select_list
FROM from_clause
[WHERE search_condition]
[GROUP BY column {, column}
     [HAVING search_condition]]
[ORDER BY column {, column}] 

 Source:

http://download.oracle.com/docs/cd/E14571_01/bi.1111/e10540/variables.htm#BIEMG3104