Encyclopedia of Database Systems

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

Time Interval

  • Christian S. Jensen
  • Richard T. Snodgrass
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1423

Synonyms

Duration; Span; Time distance; Time period

Definition

  • Definition 1:

    A time interval is a convex subset of the time domain. A time interval may be open or closed (at either end) and can be defined unambiguously by its two delimiting time instants. In a system that models the time domain using granules, an interval may be represented by a set of contiguous granules.

  • Definition 2:

    An interval is a directed duration of time. A duration is an amount of time with known length, but no specific starting or ending instants. For example, the duration “1 week” is known to have a length of 7 days, but can refer to any block of seven consecutive days. An interval is either positive, denoting forward motion of time, or negative, denoting backwards motion in time.

Key Points

Unfortunately, the term “time interval” is being used in the literature with two distinct meanings: as the time between two instants, in the general database research literature and beyond, and as a directed duration of...

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Recommended Reading

  1. 1.
    Bettini C, Dyreson CE, Evans WS, Snodgrass RT, Wang XS. A glossary of time granularity concepts. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice, LNCS 1399. Berlin: Springer; 1998. p. 406–13.CrossRefGoogle Scholar
  2. 2.
    Jensen CS, Dyreson CE, editors. A consensus glossary of temporal database concepts – February 1998 version. In Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice. LNCS 1399. Berlin: Springer; 1998. p. 367–405.Google Scholar
  3. 3.
    Lorentzos NA, Mitsopoulos YG. SQL extension for interval data. IEEE Trans Knowl Data Eng. 1997;9(3):480–99.zbMATHCrossRefGoogle Scholar

Copyright information

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

Authors and Affiliations

  1. 1.Department of Computer ScienceAalborg UniversityAalborgDenmark
  2. 2.Department of Computer ScienceUniversity of ArizonaTucsonUSA
  3. 3.Dataware VenturesTucsonUSA

Section editors and affiliations

  • Richard T. Snodgrass
    • 1
  • Christian S. Jensen
    • 2
  1. 1.University of ArizonaTucsonUSA
  2. 2.Aalborg UniversityAalborg ØstDenmark