Hierarchies

In OLAP metadata, a hierarchy is a logical structure that uses ordered levels as a means of organizing data. A hierarchy can be used to define data aggregation; for example, in a Time dimension, a hierarchy might be used to aggregate data from the “Month” level to the “Quarter” level to the “Year” level.

An MDHierarchy represents a hierarchy in the MetadataManager. MDHierarchy extends MDFolder. MDHierarchy objects contain MDLevel objects, which represent levels in the hierarchy. For example, an MDLevel might represent the Year level in a Time hierarchy.

MDHierarchy objects are contained by the MDDimension objects for which they are defined. To find the hierarchies that are defined for a dimension, call MDDimension.getHierarchies. To find the default hierarchy for a dimension, call MDDimension.getDefaultHierarchy.