(57) ABSTRACT A hierarchy may be explicitly or implicitly reflected in existing data
maintained external to hierarchy structures. Such hierarchies are referred to herein as a “pre-
existing hierarchies”. Techniques are described herein for capturing a pre-existing hierarchy
in hierarchy structures. After a pre-existing hierarchy has been captured, there exist two
independent sets of data that reflect the hierarchy: the external hierarchy definition and the
internal hierarchy defi nition. Changing either hierarchy definition changes the hierarchy …

A hierarchy may be explicitly or implicitly reflected in existing data maintained external to
hierarchy structures. Such hierarchies are referred to herein as a “pre-existing hierarchies”.
Techniques are described herein for capturing a pre-existing hierarchy in hierarchy
structures. After a pre-existing hierarchy has been captured, there exist two independent
sets of data that reflect the hierarchy: the external hierarchy definition and the internal
hierarchy definition. Changing either hierarchy definition changes the hierarchy. Therefore …