|Oracle9i OLAP User's Guide
Release 2 (9.2)
Part Number A95295-01
CWM2_OLAP_HIERARCHY , 2 of 13
A hierarchy is an OLAP metadata entity. This means that it is a logical object, identified by name and owner, within the OLAP 2 Catalog.
Hierarchies are child entities of dimension entities. Hierarchies define parent/child relationships between sets of levels. There can be multiple hierarchies associated with a single dimension, and the same level can be used in multiple hierarchies.