So exactly what is a request variable? Well, PUT succinctly:

A request variable is a variable that is used to temporarily override the value of a session variable.

And, with a little more precision, a request variable is:

A variable that is defined within the Presentation Services;

A variable whose scope (page or dashboard) is that of the associated dashboard prompt that defines the request variable and its value;

A variable whose name should not match that of a repository variable or a security SYSTEM session variable; and

A variable that overrides the value of the corresponding session variable (should it exist) for the purpose of BI Server request parsing and physical SQL construction for all requests that are ISSUED from dashboard pages that fall within the scope of the variable’s DEFINITION.

Note, USING a request variable does not change the actual value of a session variable – neither temporarily nor permanently. It simply appears to change the value for certain purposes during the execution of a request.

So exactly what is a request variable? Well, put succinctly:

A request variable is a variable that is used to temporarily override the value of a session variable.

And, with a little more precision, a request variable is:

A variable that is defined within the Presentation Services;

A variable whose scope (page or dashboard) is that of the associated dashboard prompt that defines the request variable and its value;

A variable whose name should not match that of a repository variable or a security system session variable; and

A variable that overrides the value of the corresponding session variable (should it exist) for the purpose of BI Server request parsing and physical SQL construction for all requests that are issued from dashboard pages that fall within the scope of the variable’s definition.

Note, using a request variable does not change the actual value of a session variable – neither temporarily nor permanently. It simply appears to change the value for certain purposes during the execution of a request.