Encyclopedia of Database Systems

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

Explicit Event

  • Jonas MellinEmail author
  • Mikael Berndtsson
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_515


In active databases, an explicit event is explicitly specified in the ECA rule definition.

Key Points

ECA rules were developed as an optimization of condition action rules. The performance of rule evaluation was improved by allowing, or even requiring, explicit definition of when rules should be triggered in the form of events. For example, (ONupdateAfollowed_byupdateBIFA = 5∧ B = 3 DO action) is a rule specification that is triggered by the explicit event updateAfollowed_byupdateB (i.e., a sequence of updates).


Copyright information

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

Authors and Affiliations

  1. 1.University of SkövdeThe Informatics Research CentreSkövdeSweden
  2. 2.University of SkövdeSchool of InformaticsSkövdeSweden

Section editors and affiliations

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