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Disaggregations in databases

Published:01 January 1985Publication History
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Abstract

An algebraic foundation of database schema design is presented. A new database operator, namely, disaggregation, is introduced. Beginning with “free” families, repeated applications of disaggregation and three other operators (matching function, Cartesian product, and selection) yield families of increasingly elaborate structure. In particular, families defined by one join dependency and several “embedded” functional dependencies can be obtained in this manner.

References

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        Robert J. Tufts

        The primary purpose of this moderately sized paper is to show that an algebraic approach can be used to study extensions to the relational database model and to database schema design. To do this, the paper presents a rigorous treatment of relational algebra fundamentals and then extends these into aggregations, disaggregations, matching functions, partition mappings, and constraint-free schemas. The paper concludes with a strong discussion of a bottom-up approach to schema design. The paper itself is well written and highly mathematical. It has a minimum of typographical errors (I found two), and they do not detract from the discussion. The references are few but include some classical papers on relational algebra theory. The authors do succeed in presenting a theoretic foundation for a constructive database design. The main drawback of the paper is a result of its technical rigor: It is not easily understood by the casual reader. In fact, even seasoned database professionals are advised to brush up on relational database design algorithms before tackling it (one possible reference is shown below [1]). As such, I would recommend the paper only to those pursuing theoretical algebraic extensions to the relational model.

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        • Published in

          cover image Journal of the ACM
          Journal of the ACM  Volume 32, Issue 1
          Jan. 1985
          246 pages
          ISSN:0004-5411
          EISSN:1557-735X
          DOI:10.1145/2455
          Issue’s Table of Contents

          Copyright © 1985 ACM

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          Association for Computing Machinery

          New York, NY, United States

          Publication History

          • Published: 1 January 1985
          Published in jacm Volume 32, Issue 1

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