Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Memory Locality

  • Stefan Manegold
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_686

Synonyms

Locality of reference; Locality principle; Principle of locality

Definition

Locality refers to the phenomenon that computer programs – or computational processes in general – do not access all of their data items uniformly and independently, but rather in a clustered and/or dependent/correlated manner. Some data items are accessed more often than others, repeated accesses to the same data item occur in bursts, and related items are usually accessed together, concurrently or within a short time interval.

There are two types of locality:
  1. 1.

    Temporal locality means that accesses to the same data item are grouped in time, i.e., multiple accesses to the same data item occur in rather short time intervals compared to rather long time periods where the same data item is not accessed. Hence, temporal locality is the concept that a data item that is referenced by a program at one point in time will be referenced again sometime in the near future.

     
  2. 2.

    Spatial localitymeans that data...

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Recommended Reading

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    Ailamaki AG, DeWitt DJ, Hill MD, Skounakis M. Weaving relations for cache performance. In: Proceedings of the 27th International Conference on Very Large Data Bases; 2001. p. 169–180.Google Scholar
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    Denning PJ. The working set model for program behaviour. Commun ACM. 1968;11(5):323–33.MathSciNetzbMATHCrossRefGoogle Scholar
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    Denning PJ. The locality principle. Commun ACM. 2005;48(7):19–24.CrossRefGoogle Scholar
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    Manegold S, Boncz PA, Kersten ML. Optimizing main-memory join on modern hardware. IEEE Trans Knowl Data Eng. July 2002;14(4):709–30.CrossRefGoogle Scholar
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    Shatdal A, Kant C, Naughton J. Cache conscious algorithms for relational query processing. In: Proceedings of the 20th International Conference on Very Large Data Bases; 1994. p. 510–12.Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.CWIAmsterdamThe Netherlands