Two-File Hierarchical Filing System by Ron Dell’Aquila (Technical Note 90-205; April 1990) (hereinafter “TN 90-205”) introduced the classic two-file recursive relationship. This type of relationship is ideal for tracking things like the following:
• Computer file structures
• Genealogical information
• Computer help data
• Bills of materials
• Multi-level marketing systems
This technote extends the concepts covered in TN 90-205 by defining a module of procedures which work on such a structure.
Like any recursive solution, this type of structure works at unlimited levels of depth. Whereas the depth of the relational structure of an invoicing system is known at the time the system is designed, some structures defy such a static definition.