This Article 
 Bibliographic References 
 Add to: 
An improved Algorithm Based on Subset Closures for Synthesizing a Relational Database Scheme
November 1988 (vol. 14 no. 11)
pp. 1731-1738

An algorithm for synthesizing a better relational database scheme in elementary key normal form (EKNF) is developed. This algorithm eliminates not only extraneous attributes and other redundancies, but also superfluities from a given set of functional dependences (FDs), based primarily on subset closures, Hamiltonian cycles of FDs, and equivalent subsets of attributes. Following this algorithm, a better LR-minimum FD covering is obtained. A more practical and efficient method for designing a relational database scheme in EKNF is then provided. The time complexity of the algorithm is polynomial.

[1] G. Ausielloet al., "Graph algorithms for functional dependency manipulation,"J. ACM, vol. 30. no. 4. pp. 752-766, Oct. 1983.
[2] P. A. Bernstein, "Synthesizing third normal form relations from functional dependencies,"ACM Trans. Database Syst., vol. 1, no. 4, pp. 277-298, Dec. 1976.
[3] R. Fagin, "The decomposition versus the synthetic approach to relational database design," inProc. VLDB III, Tokyo, Japan. 1977, pp. 441-446.
[4] T. W. Ling, F. W. Tompa, and T. Kameda, "An improved third normal form for relational databases,"ACM Trans. Database Syst., vol. 6, no 2, pp. 329-346, June 1981.
[5] D. Maier, "Minimum covers in the relational database,"J. ACM, vol. 27, no. 4, pp. 664-674, Oct. 1980.
[6] D. Maier,The Theory of Relatonal Databases, Potomac, MD: Computer Science Press, 1983.
[7] T. J. Teorey, D. Yang, and J. P. Fry, "A logical design methodology for relational databases using the extended entity-relationship model,"ACM Comput. Surveys, vol. 18, no. 2, pp. 197-222, June 1986.
[8] C. C. Yang,Relational Databases, Englewood Cliffs. NJ, Prentice-Halt, 1986.
[9] C. C. Yang, "Deduction graphs: An algorithm and applications,"IEEE Trans. Software Eng., to be published.
[10] C. Zaniolo, "A new normal form for the design of relational database scheme,"ACM Trans. Database Syst., vol. 7, no. 3, pp. 489-499, Sept. 1982.

Index Terms:
subset closures; relational database scheme; elementary key normal form; functional dependences; subset closures; Hamiltonian cycles; time complexity; computational complexity; database theory; relational databases; set theory
C.-C. Yang, G. Li, P.A.-B. Ng, "An improved Algorithm Based on Subset Closures for Synthesizing a Relational Database Scheme," IEEE Transactions on Software Engineering, vol. 14, no. 11, pp. 1731-1738, Nov. 1988, doi:10.1109/32.9058
Usage of this product signifies your acceptance of the Terms of Use.