Ignore Unrelated Dimensions in a SSAS Cube

Let me re-post a very useful articel by Bryan C. Smith about unrelated dimensions in a cube. The same topic as tackled in a very good SSAS Webcast by Craig Utley. By Bryan C. Smith - http://hccmsbi.blogspot.com/2007/07/ignoreunrelateddimensions.html

Imagine you have a highly simplified Adventure Works cube. In this cube, you have two measure groups, Reseller Sales and Internet Sales. Reseller Sales has relationships with the Geography and Date dimensions and has one measure, Reseller Sales Amount. Internet Sales has a relationship with just the Date dimension and a single measure, Internet Sales Amount. To simplify things even further, imagine the Geography dimension has a single attribute hierarchy, Country, and Date has three attribute hierarchies, Calendar Year, Calendar Quarter, and Date.