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Optimal covers in the relational database model

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Abstract

The problem of finding an optimal cover which has possible fewest attributes is NP-complete. It is shown here that an optimal cover can be found, using the notion of mini cover. The minimum Boolean expression of the first Delobel–Casey transform of a set of functional dependencies can be converted into corresponding mini cover, refining classic canonical cover. The relationship between optimal cover and Boolean expression minimization is built, and all theory of Boolean expression minimization can be used to find an optimal cover.

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Acknowledgments

The authors would like to thank David Maier for improving the notion of mini cover.

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Correspondence to Zhijun Xiao.

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This work is supported by the constructing program of the key discipline in Huaihua University.

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Peng, X., Xiao, Z. Optimal covers in the relational database model. Acta Informatica 53, 459–468 (2016). https://doi.org/10.1007/s00236-015-0247-9

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  • DOI: https://doi.org/10.1007/s00236-015-0247-9

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