Techniques for managing multiple hierarchies of data from a single native
hierarchy include registering a set of routines for each foreign hierarchy. The
set of routines performs a set of operations on data in the hierarchy associated
with a node. A user request is received, which indicates a particular operation
on particular data that does not correspond to a node of the native hierarchy.
Based on the user request, a first operation on a first set of one or more nodes
of a first hierarchy that is not the native hierarchy is determined. A particular
routine that corresponds to the first operation is selected from a first set of
routines registered for the first hierarchy, and is invoked. These techniques allow
a user to employ a consistent interface with the native hierarchy to reach data
in any of the hierarchies.