How the Dimensionality of an Expression is Determined

An expression is dimensioned by a union of the dimensions of all of the variables, dimensions, relations, formulas, qualified data references, and functions in the expression:

• Variables, relations, and formulas are dimensioned by the dimensions listed in the definition of the object.

  Example 1: When the price variable is dimensioned by month and product, then the expression price * 1.2 is also dimensioned by month and product.

  Example 2: When the units variable is dimensioned by month, product, and district, then the expression units * price is dimensioned by month, product, and district (even though the dimensions of the price variable are month and product only).

• Qualified data references (QDRs) are dimensioned by all of the dimensions of the associated object, except for the dimensions being qualified. (For more information about qualified data references, see "Limiting a Dimension to a Single Value Without Changing Status".)

• The return values of most OLAP DML functions are, in most cases, dimensioned by the union of the dimensions of the input arguments. However, some functions (such as aggregation functions) have fewer dimensions than the input arguments. In these cases, the dimensionality of the return value is documented in the topic for the function in OLAP DML Functions: A - K.

  
  

  Note: Unless otherwise noted, when you specify breakout dimensions or relations in an aggregation function, you change the dimensionality of the expression. The first dimension that you specify as a breakout dimension is the slowest varying and the last dimension that you specify is the fastest varying.