Hashing Schemes for Extendible Arrays
- 1 April 1977
- journal article
- Published by Association for Computing Machinery (ACM) in Journal of the ACM
- Vol. 24 (2) , 199-221
- https://doi.org/10.1145/322003.322006
Abstract
The use of hashing schemes for storing extendible arrays is investigated. It is shown that extendible hashing schemes whose worst-case access behavior is close to optimal must utilize storage inefficiently; conversely hashing schemes that utilize storage too conservatively are inevitably poor in expected access time. If requirements for the utilization of storage are relaxed slightly, then one can find rather efficient extendible hashing schemes. Specifically, for any dimensionality of arrays, one can find extendible hashing schemes which at once utilize storage well (fewer than 2 p storage locations need be set aside for storing arrays having p or fewer positions) and enjoy good access characteristics (expected access time is O (1), and worst-case access time is O (log log p ) for p - or fewer-position arrays). Moreover, at the cost of only a modest additive increase in access time, storage demands can be decreased to (1 + δ) p locations for arbitrary δ > 0.Keywords
This publication has 4 references indexed in Scilit:
- On storing ragged arrays by hashingTheory of Computing Systems, 1976
- Managing Storage for Extendible ArraysSIAM Journal on Computing, 1975
- Allocating Storage for Extendible ArraysJournal of the ACM, 1974
- Ordered hash tablesThe Computer Journal, 1974