Avoid diamond-shape relationships not covered by hierarchies

This rule analyzes dimensions to determine whether they contain diamond-shaped attribute relationships that are not covered by hierarchies.

Best Practices Recommendations

For best performance, you should typically avoid creating diamond-shaped attribute relationships.

A diamond-shaped relationship is a chain of attribute relationships that splits and rejoins but that contains no redundant relationships. For example, Day->Month->Year and Day->Quarter->Year have the same start and end points, but do not have any common relationships. The presence of multiple paths can create ambiguity when Analysis Services decides which path to aggregate along. If preserving the multiple paths is important, we strongly recommend that you resolve the ambiguity by creating user hierarchies that contain all the paths. This will ensure that data is aggregated along all the relationship paths. 

Note

When a user-defined hierarchy covers the first relationship that originates from the point of divergence, the rest of the chain is considered to be covered also.

For More Information

For more information, see Defining Attribute Relationships in SQL Server Books Online.