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Optimizing fragment constraints—A performance evaluation

Ibrahim, H., Gray, William Alexander and Fiddian, Nicholas John 2001. Optimizing fragment constraints—A performance evaluation. International journal of intelligent systems 16 (3) , pp. 285-306. 10.1002/1098-111X(200103)16:3<285::AID-INT1008>3.0.CO;2-S

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A principal problem with integrity constraints' use for monitoring dynamically changing database integrity is evaluation cost. This cost associated with performance of checking mechanisms is the main quantitative measure which must be supervised carefully. Based on literature, evaluating an integrity constraint cost includes these main components: (i) data amount accessed; (ii) data amount transferred across network; and (iii) number of sites involved. In distributed databases, where many networked sites are involved, not only amount of data accessed must be minimized but also amount of data transferred across network and number of sites involved. In [Ibrahim H, Gray WA, Fiddian NJ. SICSDD: Techniques and implementation. In Proceedings of Constraint Databases and Applications, Second International Workshop on Constraint Database Systems (CDB'97), Delphi, Greece, January 1997, pp 187-207], we introduced an integrity constraint subsystem for a relational distributed database. The subsystem consists of several techniques necessary for efficient constraint checking, particularly in a distributed environment where data distribution is transparent to application domain. Here, we show how these techniques effectively reduce constraint checking cost in such a distributed environment. This is done by analyzing and comparing generated simplified forms to respective initial constraints respecting amount of data to be accessed, amount of data transferred across network, and number of sites involved during evaluation of constraints or simplified forms. Generally, our strategy reduces data amount needing to be accessed since only fragments of relations subject to update are evaluated. Data amount transferred across network and number of sites that are involved are minimized by evaluating simplified forms at target site, i.e., site where update is performed.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Computer Science & Informatics
ISSN: 1098-111X
Last Modified: 04 Jun 2017 01:42

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