A relational model of data for large shared data banks
Communications of the ACM
An Introduction to Database Systems
An Introduction to Database Systems
A relation-based language interpreter for a content addressable file store
ACM Transactions on Database Systems (TODS)
Joined normal form: a storage encoding for relational databasess
ACM Transactions on Database Systems (TODS)
Update-by-dialogue: an interactive approach to database modification
SIGMOD '77 Proceedings of the 1977 ACM SIGMOD international conference on Management of data
A model and a method for logical data base design
VLDB '78 Proceedings of the fourth international conference on Very Large Data Bases - Volume 4
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The concept of normalisation and the definition of third normal form occupy a central place in the relational model of database. Normalisation has been described as an analytic process in which an initially unconstrained collection of relations is successively decomposed into a collection of smaller relations satisfying the constraints of the three normal forms. Normalised relations constitute the basis on which data manipulation languages - relational algebra, relational calculus and others - have been defined. As yet, however, there is no generally recognised data definition language for the relational model. A pre-requisite for this would be a constructive definition of third normal form, that is, a definition in terms of rules for building normalised relations from simple domains. This paper considers how such a definition may be achieved by applying two ideas derived from the study of programming languages; the notion of data type, and the notion of a selector as used in formal language definition. The result is an abstract syntax of relations. This is compared with the standard definition of normalisation and its completeness is critically examined.