To evaluate a dynamic hierarchy, Essbase calculates, rather than aggregates, the members and formulas. The order in which members and formulas are evaluated is defined by the solve order property. See Calculation Order.
At the time of retrieval, Essbase calculates the required member combinations and calculates any required outline member formulas. Because dynamic hierarchies are calculated, the data retrieval time may be longer than for data retrieved from stored hierarchies. However, when you design your database, dynamic hierarchies provide the following advantages:
To specify a dynamic hierarchy, tag the top member of the hierarchy as top of a dynamic hierarchy using a tool:
The following members can be tagged as top of a dynamic hierarchy:
A dimension member (generation 1). If a dimension member is tagged as top of a dynamic hierarchy, the entire dimension is considered a single dynamic hierarchy, and no other member in the dimension can be tagged as top of a dynamic hierarchy or top of a stored hierarchy.
The children of the dimension member (generation 2). If a generation 2 member is tagged as top of a dynamic hierarchy, all generation 2 members in the dimension must also be tagged as either top of a dynamic hierarchy or top of a stored hierarchy. The first hierarchy in the dimension must be a stored hierarchy.
If a member has the no-consolidation operator (~) on all its children, the member must be tagged label only. |
The dimension tagged accounts is automatically considered a dynamic hierarchy. You cannot specify the accounts dimension as a stored hierarchy.
Essbase cannot select dynamic hierarchy members for an aggregate view. See Aggregating an Aggregate Storage Database.