Defining Analysis Services Dimensions - SQL Server Analysis Services 2012 Cube Development - page 43

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Analysis Services creates a relationship from the key attribute to each non-key at-
tribute by default because the key attribute must uniquely identify each non-key at-
tribute. But note that English Promotion Category and English Promotion Type
appear to the right of Promotion Name (key attribute), whereas all other non-key
attributes appear under Promotion Name . This is because you included the pro-
motion category and promotion type levels in a user-defined hierarchy. Right-click
on the English Promotion Type attribute and choose New Attribute Relationship .
Doing so brings up the Create Attribute Relationship dialog. Set the related at-
tribute as English Promotion Category and leave the relationship type as Flexible
(may change over time) as shown in the following screenshot; then click on OK .
Attribute relationships are always one-to-many; in this example, each category could
have many promotion types. A relationship type can be flexible or rigid. Rigid rela-
tionships are rare; they indicate that each member of the related attribute will always
be associated with the same member of the source attribute. For example, Janu-
ary 21, 2013 will always be associated with the month January 2013; similarly, each
calendar month will always be associated with the corresponding year. The classi-
fication of each promotion type can change over time; hence, we should leave the
relationship type at the default value of flexible . Relationship types make an import-