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
.