Analysis of repeated hashing
A performance analysis of an overflow handling method for hash files, here called repeated hashing, is reported. The basic idea of repeated hashing is to rehash the overflow records into a smaller separate storage area; the overflow records from this area are in turn hashed into a still smaller separate storage area, etc. The expected retrieval performance and the storage requirements are analysed, both for initial loading and steady state. The problem of optimally partitioning the total storage area is considered and the optimal solution is given. It is concluded, however, that the usefulness of repeated hashing is in doubt because there are methods having the same performance but requiring less maintenance.
Keywordshashing scatter storage repeated hashing file organisation searching analysis of algorithms
Unable to display preview. Download preview PDF.
- 1.Richard Bellman,Dynamic Programming, Princeton University Press, Princeton, N.J., 1957.Google Scholar
- 2.L. H. Groner, and A. L. Goel,Concurrency in hashed file access, in J. L. Rosenfeld (ed.),Information Processing 74, North-Holland, Amsterdam, 1974, pp. 431–435.Google Scholar
- 3.Gérard Guiho,Organisation des mémoires. Influence d'une structure et étude d'optimisation, (diss). Université Paris VI, Institut de programmation, No I.P. 73.16, 1973.Google Scholar
- 4.D. E. Knuth,The Art of Computer Programming. Vol. 3:Sorting and Searching. Addison-Wesley, Mass., 1973.Google Scholar
- 5.P.-Å. Larson,Analysis of uniform hashing, Reports on computer science and mathematics, Ser. A, no. 1, Åbo Akademi, Åbo, 1978 (to appear in Acta Informatica).Google Scholar
- 6.C. A. Olson,Random access file organisation for indirectly addressed records, Proceedings of the 24th National Conference of ACM, ACM, 1969, pp. 539–549.Google Scholar
- 7.J. A. van der Pool,Optimum storage allocation for a file in steady state, IBM Journal of Research and Development, vol. 17, no. 1, 1973, pp. 27–38.Google Scholar