Encyclopedia of Database Systems

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

Nonsequenced Semantics

  • Michael H. BöhlenEmail author
  • Christian S. JensenEmail author
  • Richard T. SnodgrassEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1052


Nontemporal semantics


Nonsequenced semantics guarantees that query language statements can reference and manipulate the timestamps that capture the valid and transaction time of data in temporal databases as regular attribute values, with no built-in temporal semantics being enforced by the query language.

Key Points

A temporal database generalizes a nontemporal database and associates one or more timestamps with database entities. Different authors have suggested temporal query languages that provide advanced support for formulating temporal statements. Results of these efforts include a variety of temporal extensions of SQL, temporal algebras, and temporal logics that simplify the management of temporal data.

Languages with built-in temporal support are attractive because they offer convenient support for formulating a wide range of common temporal statements. The classical example of advanced built-in temporal support is sequenced semantics, which makes it...

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Recommended Reading

  1. 1.
    Abiteboul S, Herr L, Van den Bussche J. Temporal versus first-order logic to query temporal databases. In: Proceedings of the 15th ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems; 1996. p. 49–57.Google Scholar
  2. 2.
    Allen JF. Maintaining knowledge about temporal intervals. Commun ACM. 1983;16(11):832–43.zbMATHCrossRefGoogle Scholar
  3. 3.
    Böhlen MH, Jensen CS, Snodgrass RT. Temporal statement modifiers. ACM Trans Database Syst. 2000;25(4):48.zbMATHCrossRefGoogle Scholar
  4. 4.
    Toman D, Niwiński D. First-order queries over temporal databases inexpressible in temporal logic. In: Advances in Database Technology, Proceedings of the 5th International Conference on Extending Database Technology; 1996. p. 307–24.CrossRefGoogle Scholar

Copyright information

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

Authors and Affiliations

  1. 1.Free University of Bozen-BolzanoBozen-BolzanoItaly
  2. 2.Department of Computer ScienceAalborg UniversityAalborgDenmark
  3. 3.Department of Computer ScienceUniversity of ArizonaTucsonUSA
  4. 4.Dataware VenturesTucsonUSA
  5. 5.University of ZurichZürichSwitzerland

Section editors and affiliations

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