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In this paper, we show that some Codd third normal form relations may contain "superfluous" attributes because the definitions of transitive dependency and prime attribute are inadequate when applied to ... To correct this, an improved third normal form is defined and an algorithm is given to construct a set of relations from a given set of functional dependencies in such a way that the superfluous attributes ... ACKNOWLEDGMENTS The authors wish to acknowledge the many useful comments and suggestions they received on previous versions of this paper, and they give special thanks to David Maier and the referees. ...doi:10.1145/319566.319583 fatcat:fwdcuh2xtrahbg7kbtcmogfjb4
Lecture Notes in Computer Science
Hence, the Boyce-Codd-Heath normal form is not suitable for SQL databases. ... In the relational model of data the Boyce-Codd-Heath normal form, commonly just known as Boyce-Codd normal form, guarantees the elimination of data redundancy in terms of functional dependencies. ... The second author is supported by a research grant of the Alfried Krupp von Bohlen and Halbach foundation, administered by the German Scholars organization. ...doi:10.1007/978-3-642-20920-8_14 fatcat:eufykl7uojcn7jvrkuayhu46xu
A new type of dependency, which includes the well-known functional dependencies as a special case, is defined for relational databases. ... This fourth normal form is strictly stronger than Codd's "improved third normal form" (or "Boyce-Codd normal form"). ... The original schema T" is in third normal form and even in the stronger "Boyce-Codd normal form"  since it is "all key" (that is, no proper subset of the four column names form a key for T*). ...doi:10.1145/320557.320571 fatcat:hl44dkis7fbtrkdwsqgkn4s4yq
Ginsburg, Seymour (1-SCA); Hull, Richard (1-SCA) Characterizations for functional dependency and Boyce-Codd normal form families. Theoret. Comput. Sci. 26 (1983), no. 3, 243-286. ... A Boyce-Codd normal form family (BCNF family) is defined as a set of instances, all satisfying a given set of functional dependencies and all being in the well-known Boyce-Codd normal form. ...
In this paper, based on equivalence classes of attributes there are formulated necessary and sufficient conditions that constraint a database schema to be in the second, third or Boyce-Codd normal forms ... These conditions offer a polynomial complexity for the testing algorithms of the normalizations level. ... The normal forms based on functional dependencies are first normal form (1NF), second normal form (2NF), third normal form (3NF) and Boyce-Codd normal form (BCNF). ...doaj:e56db9e3cf194c0cae0cdca420e38eb0 fatcat:lc354jvr4ve27fkq73bqfz5f7i
We define a syntactic Boyce-Codd-Heath Normal Form condition, and show that the condition characterizes schemata that will never have any redundant data value occurrences in their instances. ... Over bags, keys and functional dependencies interact differently from how they interact over relations. ... Acknowledgements We would like to thank David Maier for informing us about the problem of the interaction of keys and FDs under bag semantics. ...doi:10.1016/j.ipl.2010.06.002 fatcat:oeiu3446uzclniyisjbsxxndni
Particular attention is paid to the analysis of the semilattice of closed sets, the lattice of all closure operations on a given set and to a new characterization of normal form relation schemes. ... Libkin and LB. Muchnik, Functional dependencies in relational databases: A lattice point of view, Discrete Applied Mathematics 40 (1992) 1555185. ... FD stands for functional dependency, SL for semilattice, SSL for subsemilattice, 2NF, 3NF, BCNF for the second, third and Boyce-Codd normal forms respectively. ...doi:10.1016/0166-218x(92)90028-9 fatcat:hvgqqtv5qjd75ou3gw4wqqsvla
For the problems testing third and Boyce-Codd normal forms, which are known to be NP-complete for relation schemes, this new charac- terization helps establish polynomial algorithms if the input is a relation ... Summary: “A new characterization of relational database schemes in normal forms is given. This characterization is based on the properties of the semilattice of closed sets of attributes. ...
Relational Database Designing and Normalization approach is an essential work for the designing of relation up to higher normal form in the field of Database designer. ... Database Relation stored information into two dimensional matrix form i.e. rows and column. ... A relation must be in INF and 2NF then it can further process for third normal form and there should not be transitive dependency on the key attribute. Boyce-Codd normal form is stricter than 3NF. ...doi:10.5120/ijca2017915626 fatcat:dzqn6fpnbbd4ves2we2j2nzlia
Variants of the classical syntactic Boyce-Codd and Third Normal Forms are established. ... A design theory is developed for functional dependencies with degrees of certainty, including efficient axiomatic and algorithmic characterizations of their implication problem. ... a better chance of obtaining a dependencypreserving, lossless Boyce-Codd normal form than the Boyce-Codd normal form decomposition approach does. ...doi:10.1145/2983323.2983801 dblp:conf/cikm/LinkP16 fatcat:fozo7fjjuzfonipdikczuccrhi
It comprises a synthesis of the most common inference models of functional dependencies, deals with the problems of building covers for sets of functional dependencies, makes a synthesizes of normal forms ... , presents trends regarding normalization algorithms and provides a temporal complexity of those. ... A stricter definition than 3FN was proposed by Codd and Boyce  and is known under the name Boyce-Codd Normal Form (BCNF). ...doaj:231f95af35284c8882fa9c201cad6222 fatcat:cx27kxsukzedzpuymjq524tsua
When the only constraints are functional dependencies (FDs), this new normal form is proved to be stronger than the third normal form (3NF) yet weaker than BCNF. ... It is shown that either Boyce-Codd normal form (BCNF) or 4NF are the exact conditions needed to ensure most of the design goals. ...
We also show how tractability can be improved in several special cases (one involves a novel application of Boyce-Codd normal form) and present a practical hybrid query evaluation method.” 2004e:68024 ... The results pre- pare the grounds for normal forms in object-oriented data models and subsequently for computer aided object-oriented database de- sign, following the decomposition approach for the relational ...
Axiomatic and linear-time algorithmic characterizations of the associated implication problem are established. These foundations enable us to propose a Boyce-Codd normal form for SQL. ... Unlike the relational case, there are SQL schemata that cannot be converted into Boyce-Codd normal form. ... The original techniques for this (de-)normalization framework are based on the fundamental notions of functional dependency, data redundancy, and Boyce-Codd normal form. ...doi:10.1145/2882903.2915239 dblp:conf/sigmod/KohlerL16 fatcat:ppj6crvwlvdtvikwceanei6lau
It is shown that a necessary and sufficient condition for the absence of any of these types of replacement anomalies is that the scheme be in Boyce-Codd normal form.” ... High-order objects are formally defined and characterized for database schemes with functional, inclusion, and exclusion de- pendencies. ...
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