Relative information capacity of simple relational database schemata
SIAM Journal on Computing
IEEE Transactions on Software Engineering
Elements of relational database theory
Handbook of theoretical computer science (vol. B)
Elements of information theory
Elements of information theory
An improved third normal form for relational databases
ACM Transactions on Database Systems (TODS)
A normal form for relational databases that is based on domains and keys
ACM Transactions on Database Systems (TODS)
A new normal form for the design of relational database schemata
ACM Transactions on Database Systems (TODS)
Synthesizing third normal form relations from functional dependencies
ACM Transactions on Database Systems (TODS)
Equivalence of keyed relational schemas by conjunctive queries
Journal of Computer and System Sciences
PODS '00 Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
A Web Odyssey: from Codd to XML
PODS '01 Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
A Guided Tour of Relational Databases and Beyond
A Guided Tour of Relational Databases and Beyond
Normal forms and relational database operators
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
Justification for Inclusion Dependency Normal Form
IEEE Transactions on Knowledge and Data Engineering
The Theory of Probabilistic Databases
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
Achievements of Relational Database Schema Design Theory Revisited
Selected Papers from a Workshop on Semantics in Databases
Developing XML Documents with Guaranteed ``Good'' Properties
ER '01 Proceedings of the 20th International Conference on Conceptual Modeling: Conceptual Modeling
Why is the snowflake schema a good data warehouse design?
Information Systems
A normal form for XML documents
ACM Transactions on Database Systems (TODS)
Database Systems: An Application Oriented Approach, Complete Version (2nd Edition)
Database Systems: An Application Oriented Approach, Complete Version (2nd Edition)
An information-theoretic approach to normal forms for relational and XML data
Journal of the ACM (JACM)
A sophisticate's introduction to database normalization theory
VLDB '78 Proceedings of the fourth international conference on Very Large Data Bases - Volume 4
Dependency-preserving normalization of relational and XML data
DBPL'05 Proceedings of the 10th international conference on Database Programming Languages
ACM SIGMOD Record
Dependency-preserving normalization of relational and XML data
Journal of Computer and System Sciences
XML design for relational storage
Proceedings of the 16th international conference on World Wide Web
On approximating optimum repairs for functional dependency violations
Proceedings of the 12th International Conference on Database Theory
Boolean Constraints for XML Modeling
Proceedings of the 2009 conference on Information Modelling and Knowledge Bases XX
An information-theoretic analysis of worst-case redundancy in database design
ACM Transactions on Database Systems (TODS)
Encoding databases satisfying a given set of dependencies
FoIKS'12 Proceedings of the 7th international conference on Foundations of Information and Knowledge Systems
XSym'07 Proceedings of the 5th international conference on Database and XML Technologies
Formal Framework of XML Document Schema Design
International Journal of Information Retrieval Research
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A recently introduced information-theoretic approach to analyzing redundancies in database design was used to justify normal forms like BCNF that completely eliminate redundancies. The main notion is that of an information content of each datum in an instance (which is a number in [0,1]): the closer to 1, the less redundancy it carries. In practice, however, one usually settles for 3NF which, unlike BCNF, may not eliminate all redundancies but always guarantees dependency preservation.In this paper we use the information-theoretic approach to prove that 3NF is the best normal form if one needs to achieve dependency preservation. For each dependency-preserving normal form, we define the price of dependency preservation as an information-theoretic measure of redundancy that gets introduced to compensate for dependency preservation. This is a number in the [0,1] range: the smaller it is, the less redundancy a normal form guarantees. We prove that for every dependency-preserving normal form, the price of dependency preservation is at least 1/2, and it is precisely 1/2 for 3NF. Hence, 3NF has the least amount of redundancy among all dependency-preserving normal forms. We also show that, information-theoretically, unnormalized schemas have at least twice the amount of redundancy than schemas in 3NF.