Encyclopedia of Database Systems

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

Range Query

  • Mirella M. Moro
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_753

Synonyms

Range search; Range selection

Definition

Consider a relation R with some numeric attribute A taking values over an (ordered) domain D. A range query retrieves all tuples in R whose attribute A has values in the interval [low, high]. That is, low≤R.A≤high. The range interval may be closed as aforementioned, open (e.g., low<R.A<high), or half-open in either side (e.g., low<R.A≤high). A range query can also be one-sided (e.g., low ≤ R.A retrieves all tuples with R.A value greater or equal to low). When low=high, the range query becomes an equality (or membership) query.

Key Points

Range queries involve numeric (or numerical) attributes. These are attributes whose domain is totally ordered and thus a query interval (e.g., [low, high]) can be formed. In contrast, attributes whose domain is not naturally ordered are called categorical (or nominal). Range queries correspond to selections and are thus amenable to indexing. The standard access method for a range query on some...

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Copyright information

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

Authors and Affiliations

  1. 1.Departamento de Ciencia da ComputaçaoUniversidade Federal de Minas Gerais – UFMGBelo HorizonteBrazil

Section editors and affiliations

  • Vassilis J. Tsotras
    • 1
  1. 1.University of California-RiversideRiversideUSA