Encyclopedia of Database Systems

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

Absolute Time

  • Christian S. Jensen
  • Richard T. Snodgrass
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1407

Definition

A temporal database contains time-referenced, or timestamped, facts. A time reference in such a database is absolute if its value is independent of the context, including the current time, now.

Key Points

An example is “Mary’s salary was raised on March 30, 2007.” The fact here is that Mary’s salary was raised. The absolute time reference is March 30, 2007, which is a time instant at the granularity of day.

Another example is “Mary’s monthly salary was $15,000 from January 1, 2006 to November 30, 2007.” In this example, the absolute time reference is the time period [January 1, 2006–November 30, 2007].

Absolute time can be contrasted with relative time.

Cross-References

Recommended Reading

  1. 1.
    Bettini C, Dyreson CE, Evans WS, Snodgrass RT, Wang XS. The glossary of time granularity concepts. In: Jajodia S, Etzion O, Sripada S, editors. Temporal databases: research and practice. LNCS, vol. 1399. Berlin: Springer; 1998, p. 406–413.Google Scholar
  2. 2.
    Jensen CS, Dyreson CE, editors. The consensus glossary of temporal database concepts – February 1998 version. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice. LNCS, vol. 1399. Berlin: Springer; 1998. p. 367–405.Google 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