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Author Graham, Marc H. ♦ Wang, Ke
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Copyright Year ©1990
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Abstract The question “Is a given join dependency equivalent to some set of multivalued dependencies?” led to the development of acyclicity theory [1]. The central question of this paper is: “Is a given equality-generating dependency equivalent to a set of functional dependencies?” An algorithm is presented that answers that question in polynomial time without using the chase process and, in the case of a “yes” answer, can be used to find (a cover of) the set of functional dependencies involved. This question is also related to the similar question about join dependencies and multivalued dependencies by proving a result about the hypergraph representation of an egd. It is interesting to note that a minimal representation of an egd must be β-acyclic for the egd to be equivalent to a set of fd's, in contrast to the jd/mvd case, in which only α-acyclicity is needed. The β-acyclicity of an egd not necessarily minimal is always sufficient for the egd to be equivalent to a set of fd's as shown. Finally, the algorithm is extended for a single egd to answer the question whether a set of egd's with the same right-hand-side column is equivalent to a set of fd's.
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 1990-07-01
Publisher Place New York
e-ISSN 1557735X
Journal Journal of the ACM (JACM)
Volume Number 37
Issue Number 3
Page Count 17
Starting Page 474
Ending Page 490


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Source: ACM Digital Library