Hierarchical databases were standard thirty years ago, but have been completely supplanted by relational databases since, in spite of hierarchy remaining the most common way in which we organize information in other spheres. The goal of this research project is to re-evaluate hierarchical databases in the light of the progress made in database technology. The thesis is that relational databases supplanted hierarchical databases not because flat relations provided a superior organization of the data, but rather on account of other crucial benefits relational technology provided, namely the separation of data organization from application logic and the notion of a declarative query language. The approach in this project is to begin with LDAP (Lightweight Directory Access Protocol) as a rudimentary hierarchical database, and to extend it to provide full-fledged database functionality. The results of this project will demonstrate the feasibility and value of building a hierarchical database as a far more flexible and scalable structure than the relational databases that are prevalent today. www.eecs.umich.edu/~jag/
