The structure of the relational database model
The structure of the relational database model
On semantic issues connected with keys in relational databases permitting null values
Journal of Information Processing and Cybernetics
Boyce-Codd normal form and object normal forms
Information Processing Letters
The design of relational databases
The design of relational databases
The number of keys in relational and nested relational databases
Discrete Applied Mathematics - Special issue on combinatorial problems in databases
Relational database theory
A note on relation schemes which are in 3NF but not in BCNF
Information Processing Letters
Asymptotic properties of keys and functional dependencies in random databases
Theoretical Computer Science - Special issue: database theory
The entity-relationship model—toward a unified view of data
ACM Transactions on Database Systems (TODS) - Special issue: papers from the international conference on very large data bases: September 22–24, 1975, Framingham, MA
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Entity-Relationship Modeling: Foundations of Database Technology
Entity-Relationship Modeling: Foundations of Database Technology
Information Systems
Reducing inference control to access control for normalized database schemas
Information Processing Letters
EDBT '08 Proceedings of the 11th international conference on Extending database technology: Advances in database technology
On Keys and Functional Dependencies as First-Class Citizens in Description Logics
Journal of Automated Reasoning
Efficient reasoning about a robust XML key fragment
ACM Transactions on Database Systems (TODS)
Towards a Theory of Conceptual Modelling
ER '09 Proceedings of the ER 2009 Workshops (CoMoL, ETheCoM, FP-UML, MOST-ONISW, QoIS, RIGiM, SeCoGIS) on Advances in Conceptual Modeling - Challenging Perspectives
On Codd Families of Keys over Incomplete Relations
The Computer Journal
| Hi-index | 0.00 |
Relational database schemes comprise semantic constraints to formally capture at least part of the "real-world" semantics of an application. Functional dependencies constitute a basic and widely studied class of such constraints. Accordingly, many properties of this class are known, including the insight that the number of minimal keys --- as determined by a declared set of functional dependencies --- might vary extensively, from just one to exponentially many (in the number of the underlying attributes). The case of just one minimal key is known to be characterized by the set of extremal attributes forming a minimal key. Starting from this result, the present work studies schemes having only a few minimal keys. In particular, we consider the cases of schemes having two and three minimal keys, and then suggest some research for dealing with the more general case of n minimal keys. Furthermore we study the impact of additionally requiring the schemes to be in Boyce-Codd normal form or Third normal form.