unlimited-tier hierarchy

A table relationship which is used for more flexible, dynamic queries than tables in a strict hierarchy. Unlimited-tier hierarchies provide an interactive way of assigning elements, like rooms, costs, and tasks, to a hierarchy that may be many levels deep.

For example, an unlimited-tier hierarchy can allow account codes to summarize to other account codes. Fields from this hierarchical table validate on inventory tables to be categorized. You could have the Accounts table’s Account Code as a hierarchical foreign key field in the Work Requests table so you could summarize work requests to different levels of accounts.