MDX - What is Set?

A Set is a collection of tuples which defined using same dimensions, both type and number. Set is enclosed within curly braces { and }. following is the example of set based on Adventure Works sample cube.

Tuples ([Customer].[Country].[India]) and ([Customer].[Country].[France]) are from exact same dimension. So collection of such tuples are valid Set.

{ ([Customer].[Country].[India]), ([Customer].[Country].[France]) }

A set can contain zero, one more tuples. A Zero Tuple Set is called as empty set. An enpty set is represented as

{ }