Encyclopedia of Database Systems

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


  • George KarabatisEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_732


A polytransaction T+ is a transitive closure of a transaction T submitted to an Interdependent Data Management System (a type of a multidatabase system which enforces dependencies among related data objects). The transitive closure is computed with respect to an Interdatabase Dependency Schema (IDS) consisting of a collection of data dependency descriptors (D3s), which specify the dependencies between data objects.

Key Points

Data objects in multiple (possibly distributed and/or heterogeneous) systems which form dependencies among them are called interdependent data. These dependencies are identified through data dependency descriptors (D3s). A D3 specifies the relationships between source and target objects including how much inconsistency can be tolerated between them before it is necessary to restore it, and the actions to take to maintain consistency when it reaches intolerable levels. All these D3s together form an Interdatabase Dependency Schema (IDS) [3].

When a...

This is a preview of subscription content, log in to check access.

Recommended Reading

  1. 1.
    Karabatis G, Rusinkiewicz M, Sheth A. Correctness and enforcement of multidatabase interdependencies. In: Advanced database systems LNCS, vol 759. London: Springer; 1993. p. 337–58.Google Scholar
  2. 2.
    Karabatis G, Rusinkiewicz M, Sheth A. Interdependent database systems. In: Elmagarmid A, Rusinkieuicz M, Sheth A, editors. Management of heterogeneous and autonomous database systems. San Francisco: Morgan-Kaufmann; 1999. p. 217–52.Google Scholar
  3. 3.
    Rusinkiewicz M, Sheth A, Karabatis G. Specifying interdatabase dependencies in a multidatabase environment. IEEE Comput. 1991;24(12):46–53.CrossRefGoogle Scholar

Copyright information

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

Authors and Affiliations

  1. 1.University of Maryland, Baltimore Country (UMBC)BaltimoreUSA

Section editors and affiliations

  • Panos K. Chrysanthis
    • 1
  1. 1.Dept. of Computer ScienceUniv. of PittsburghPittsburghUSA