Entity-relationship diagrams and their extensions play a fundamental role for relational databases, and they are widely accepted by the database design community as standard tools for the first stages of development. However, there are a number of issues closely connected with design, including the need for more complete semantics for data domains and sophisticated constraints; the demand for easier ways to expand and evolve an existing database; and the usability of database models for both management and query planning.

Being a listing of relation names and attribute names, a database schema suggests the adoption of a two-dimensional structure as a basis for modelling a new or existing database. This work introduces a representation of this type called the design matrix, with at least the same expressive power as that of an enhanced entity-relationship (EER) diagram, and capable of addressing some of the shortcomings pointed out by recent literature.