Encyclopedia of Database Systems

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


  • Christian S. JensenEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1416


Existence time; Temporal domain


The lifespan of a database object is the time during which the corresponding real-world object exists in the modeled reality.

Key Points

Some temporal data models, e.g., conceptual models, provide built-in support for the capture of lifespans, while other models do not. It may be observed that lifespans can be reduced to valid times, in the sense that the lifespan of an object o is the valid time of the fact “o exists.”

In the general case, the lifespan of an object is an arbitrary subset of the time domain and is naturally captured by a temporal element timestamp.

The synonym “existence time” is also used for this concept.


Recommended Reading

  1. 1.
    Jensen CS, Dyreson CE, editors. Böhlen M, Clifford J, Elmasri R, Gadia SK, Grandi F, Hayes P, Jajodia S, Käfer W, Kline N, Lorentzos N, Mitsopoulos Y, Montanari A, Nonen D, Peressi E, Pernici B, Roddick JF, Sarda NL, Scalas MR, Segev A, Snodgrass RT, Soo MD, Tansel A, Tiberio R, Wiederhold G. A 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

Section editors and affiliations

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