Encyclopedia of Database Systems

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

Timeslice Operator

  • Christian S. Jensen
  • Richard T. Snodgrass
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1426

Synonyms

Rollback operator; State query

Definition

The valid-timeslice operator may be applied to any temporal relation that captures valid time. Given also a valid-time element as a parameter, it returns the argument relation reduced in the valid-time dimension to just those time(s) specified by the valid-time element. The transaction timeslice operator is defined similarly, with the exception that the argument relation must capture transaction time.

Key Points

Several types of timeslice operators are possible. Some may restrict the time parameter to intervals or instants. Some operators may, given an instant parameter, return a conventional relation or a transaction-time relation when applied to a valid-time or a bitemporal relation, respectively; other operators may always return a result relation of the same type as the argument relation.

Oracle supports timeslicing through its flashback queries. Such queries can retrieve all the versions of a row between two transaction times (a...

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Recommended Reading

  1. 1.
    Jensen CS, Dyreson CE. A consensus glossary of temporal database concepts – February 1998 version. In: Etzion O, Jajodia S, Sripada S, editors.Temporal databases: research and practice. Berlin: Springer-Verlag; 1998. p. 367–405. LNCS 1399.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