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Support for ragged and unbalanced hierarchies


Besides balanced hierarchies, IBM Alphablox cubes support dimensions that are ragged or unbalanced. The following descriptions include issues you should be aware of.

Ragged Hierarchies

In a ragged hierarchy, null values can appear in any of the level columns. Null column values between member names are skipped, so a parent can have a child member multiple levels below the parent level. The children of USA shown in the example below are CA and Washington DC . The levels provide a meaningful context to its members in the ragged hierarchies. Thus, while Washington DC is a child of USA , it is included at the City level with San Francisco and Los Angeles.

Country

State

City

USA

CA

San Francisco

USA

CA

Los Angeles

USA

<NULL>

Washington DC

Vatican City

<NULL>

Vatican City

Unbalanced Hierarchies

In an unbalanced hierarchy, null values can appear on the lower levels of the hierarchy. A parent member's children will always be in the level below that of the parent. In this hierarchy, the levels do not provide a meaningful context to its members - Washington DC is at the same level as CA in this example. A better example of an unbalanced hierarchy might be an organizational chart.

Level 1

Level 2

Level 3

USA

CA

San Francisco

USA

CA

Los Angeles

USA

Washington DC

<NULL>

Vatican City

Vatican City

<NULL>

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