Hash Tables:Historical Notes

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Historical Notes

In this section we present some of the history of hash tables. The idea of hashing seems to have been discovered simultaneously by two groups of researchers. Knuth [37] cites an internal IBM memorandum in January 1953 by H. P. Luhn that suggested the use of hashing with chaining. Building on Luhn’s work, A. D. Linh suggested a method of open addressing that assigns the probe sequence x0, lx0/10J, lx0/100J, lx0/1000J,... to the element x.

At approximately the same time, another group of researchers at IBM: G. M. Amdahl, E. M. Boehme, N. Rochester and A. L. Samuel implemented hashing in an assembly program for the IBM 701 computer. Amdahl is credited with the idea of open addressing with linear probing.

The first published work on hash tables was by A. I. Dumey [24], who described hashing with chaining and discussed the idea of using remainder modulo a prime as a hash function.

Ershov [25], working in Russia and independently of Amdahl, described open addressing with linear probing.

Peterson [51] wrote the first major article discussing the problem of searching in large files and coined the term “open addressing.” Buchholz [7] also gave a survey of the searching problem with a very good discussion of hashing techniques at the time. Theoretical analyses of linear probing were first presented by Konheim and Weiss [39] and Podderjugin. Another, very influential, survey of hashing was given by Morris [47]. Morris’ survey is the first published use of the word “hashing” although it was already in common use by practitioners at that time.

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