Encyclopedia of Database Systems

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

Active Database Coupling Modes

  • Mikael BerndtssonEmail author
  • Jonas Mellin
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_503


Coupling modes specify execution points for ECA rule conditions and ECA rule actions with respect to the triggering event and the transaction model.

Historical Background

Coupling modes for ECA rules were first suggested in the HiPAC project [2, 3].


Coupling modes are specified for event-condition couplings and for condition-action couplings. In detail, the event-condition coupling specifies when the condition should be evaluated with respect to the triggering event, and the condition-action coupling specifies when the rule action should be executed with respect to the evaluated rule condition (if condition is evaluated to true).

The three most common coupling modes are immediate, deferred, and decoupled. The immediate coupling mode preempts the execution of the transaction and immediately initiates condition evaluation and action execution. In the deferred coupling mode, condition evaluation and action execution is deferred to the end of the transaction (before...

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Recommended Reading

  1. 1.
    Branding H, Buchmann A, Kudrass T, Zimmermann J. Rules in an open system: the REACH rule system. In: Proceedings of the 1st International Workshop on Rules in Database Systems, Workshops in Computing; 1994. p. 111–26.Google Scholar
  2. 2.
    Dayal U, Blaustein BA, Buchmann SC, et al. The HiPAC project: combining active databases and timing constraints. ACM SIGMOD Rec. 1988a;17(1):51–70.CrossRefGoogle Scholar
  3. 3.
    Dayal U, Blaustein B, Buchmann A, Chakravarthy S, et al. HiPAC: a research project in active, time-constrained database management. Technical report. CCA-88-02. Cambridge: Xerox Advanced Information Technology; 1988b.Google Scholar

Copyright information

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

Authors and Affiliations

  1. 1.University of Skövde, The Informatics Research CentreSkövdeSweden
  2. 2.University of Skövde, School of InformaticsSkövdeSweden

Section editors and affiliations

  • M. Tamer Özsu
    • 1
  1. 1.Cheriton School of Computer ScienceUniversity of WaterlooWaterlooCanada