Database restructures may be forced by some aggregate storage database outline changes, including changes to hierarchies. A hierarchy comprises a top member and its descendants.
A dynamic hierarchy includes only one stored level. The Accounts dimension is a dynamic hierarchy.
An attribute dimension is one hierarchy. The generation 1 member is the top member of the hierarchy.
If a standard dimension is not tagged as multiple hierarchies enabled, it is one hierarchy. The generation 1 member is the top member of the hierarchy.
If a standard dimension is tagged as multiple hierarchies enabled, it contains multiple hierarchies. The generation 2 members are the top members of the hierarchies. For example, the Products dimension in ASOsamp.Sample contains two hierarchies. The top members are the generation 2 members All Merchandise and High End Merchandise.