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Author McCune, William W. ♦ Henschen, Lawrence J.
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Copyright Year ©1989
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Abstract If a relational database is required to satisfy a set of integrity constraints, then when the database is updated, one must ensure that it continues to satisfy the constraints. It is desirable not to have to evaluate each constraint after each update. A method is described that takes a constraint $\textit{C}$ and a class of updates, and either proves that an update in the class cannot violate $\textit{C},$ or produces a formula $\textit{C'}$ (a complete test) that is satisfied before the update if and only if $\textit{C}$ would continue to be satisfied were the update to occur. $\textit{C'}$ is frequently much easier to evaluate than $\textit{C}.$ In addition, a formula $\textit{D}$ (a sufficient test) is sometimes produced such that if $\textit{D}$ is satisfied before the update, then $\textit{C}$ would continue to be satisfied were the update to occur. The method is proved correct. The method is substantially more general than other reported techniques for this problem. The method has been implemented, and a number of experiments with the implementation are presented.
ISSN 00045411
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1989-01-01
Publisher Place New York
e-ISSN 1557735X
Journal Journal of the ACM (JACM)
Volume Number 36
Issue Number 1
Page Count 23
Starting Page 46
Ending Page 68


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Source: ACM Digital Library