The Problem Of Multiple Paths In A Database Schema

Some problems concerned with the presence of multiple paths between two entities in a database schema are examined. A notion of equivalent paths is described and used to define a "natural" subschema. The presence of natural subschemata gives rise to an integrity constraint for which simple graph-theoretic results are obtained. These results are also used to suggest path finding methods for high-level query systems in which paths between entities need not be specified.