Information Modeling and Relational Databases, 2nd Edition

ORM Glossary

This glossary lists key terms and symbols used in Object-Role Modeling (ORM), and briefly explains their meaning. A concise explanation of other technical terms may be found in the chapter summaries. Further details on technical terms may be accessed by using the Index.

Alethic constraint:

Constraint that holds necessarily for all states of the model.

Arity:

Number of roles in a relationship (unary = 1, binary = 2, ternary = 3, etc.).

Asserted fact:

Fact that is simply asserted, rather than being derived from others; also called a primitive fact or base fact.

Asserted subtype:

Subtype that is simply asserted (not defined by a subtype definition).

Association:

Relationship type, usually involving at least two roles.

Atomic ...