MDX Function and Operator Reference - Professional SQL Server Analysis Services 2005 with MDX - page 1129

This function returns the username of the user executing the function.
The name is returned in Domain\Name format. For example, if user Lisa
in the domain ITCMAIN invokes a calculation that uses this function, it
will return "ITCMAIN\Lisa."

See also: CustomData

V

ValidMeasure ( tuple ) Returns: tuple Extension: AS2005, AS2000

This function returns the value of the measure specified by the tuple
where the measure has been projected to a meaningful intersection in a
virtual cube. When a virtual cube joins two or more regular cubes that
have different dimensionality, all base data values in the virtual cube are
found at the ALL levels of each dimension that is not shared by all cubes.
You can always reference these base data cells by explicitly qualifying
the measure reference to the ALL level of each dimension (for example,
([Measures].[Employee Count], [Product].[All Products], [Customer].[All
Customers])). This function is a convenience because you do not need to
explicitly reference all of the dimensions that are not relevant to the
measure.

The tuple may contain members from any dimensions of the virtual cube
(and it does not need to have a measure in it). Any members for non-
common dimensions for the measure are projected to the ALL member.
Any members for dimensions that are in common are used to locate the
value returned. The function can be used with regular cubes, but in that
case it does nothing to change the location of reference for the measure.

Note that you need an extra set of parentheses to define the tuple if it
contains more than one member
ValidMeasure ( ([Measures].[Qty Purchased],
[Time].PrevMember) )

instead of
ValidMeasure ( [Measures].[Qty Purchased],
[Time].PrevMember )