An improved third normal form for relational databases

In this paper, we show that some Codd third normal form relations may contain “superfluous” attributes because the definitions of transitive dependency and prime attribute are inadequate when applied to sets of relations. To correct this, an improved third normal form is defined and an algorithm is given to construct a set of relations from a given set of functional dependencies in such a way that the superfluous attributes are guaranteed to be removed. This new normal form is compared with other existing definitions of third normal form, and the deletion normalization method proposed is shown to subsume the decomposition method of normalization.

[1]  Jorma Rissanen,et al.  Independent components of relations , 1977, TODS.

[2]  E. F. Codd,et al.  Recent Investigations in Relational Data Base Systems , 1974, ACM Pacific.

[3]  FaginRonald.  Multivalued dependencies and a new normal form for relational databases , 1977 .

[4]  Claudio L. Lucchesi,et al.  Candidate Keys for Relations , 1978, J. Comput. Syst. Sci..

[5]  Philip A. Bernstein,et al.  Comment on "Decomposition of a Data Base and the Theory of Boolean Switching Functions" , 1977, IBM J. Res. Dev..

[6]  Philip A. Bernstein,et al.  Synthesizing third normal form relations from functional dependencies , 1976, TODS.

[7]  János Demetrovics.  On the Number of Candidate Keys , 1978, Inf. Process. Lett..

[8]  E. F. Codd,et al.  A relational model of data for large shared data banks , 1970, CACM.

[9]  Ronald Fagin,et al.  Multivalued dependencies and a new normal form for relational databases , 1977, TODS.

[10]  Claude Delobel,et al.  Normalization and hierarchical dependencies in the relational data model , 1978, TODS.

[11]  E. F. Codd,et al.  A Relational Model for Large Shared Data Banks , 1970 .

[12]  Christos H. Papadimitriou.  Efficient Search for Rationals , 1979, Inf. Process. Lett..

[13]  Joachim Biskup,et al.  Synthesizing independent database schemas , 1979, SIGMOD '79.

[14]  David Maier.  Minimum Covers in Relational Database Model , 1980, JACM.

[15]  Sylvia Louise Osborn.  Normal forms for relational data bases. , 1978 .

[16]  Ronald Fagin,et al.  Functional Dependencies in a Relational Data Base and Propositional Logic , 1977, IBM J. Res. Dev..

[17]  Sylvia L. Osborn.  Testing for Existence of a Covering Boyce-Codd normal Form , 1979, Inf. Process. Lett..

[18]  Catriel Beeri,et al.  A Sophisticate's Introduction to Database Normalization Theory , 1978, VLDB.

[19]  Tok-Wang Ling.  Improving data base integrity based on functional dependencies. , 1978 .

[20]  Alfred V. Aho,et al.  The theory of joins in relational data bases , 1977, 18th Annual Symposium on Foundations of Computer Science (sfcs 1977).

[21]  E. F. Codd,et al.  Further Normalization of the Data Base Relational Model , 1971, Research Report / RJ / IBM / San Jose, California.

[22]  David Maier.  Minimum covers in the relational database model (Extended Abstract) , 1979, STOC '79.

[23]  A BernsteinPhilip,et al.  Computational problems related to the design of normal form relational schemas , 1979 .

[24]  Clement T. Yu,et al.  On the Complexity of Finding the Set of Candidate Keys for a Given Set of Functional Dependencies , 1976, Inf. Process. Lett..

[25]  W. W. Armstrong,et al.  Dependency Structures of Data Base Relationships , 1974, IFIP Congress.