Abstract
It is very important to use database technology for a large-scale system such as ERP and MIS. A good database design may improve the performance of the system. Some researches show that a γ-acyclic database scheme has many good properties, e.g., each connected join expression is monotonous, which helps to improve query performance of the database system. This what conditions are needed to generate a γ-acyclic database scheme for a given relational scheme? In this paper, the sufficient and necessary condition of the existence of γ-acyclic, join-lossless and dependencies-preserved database schemes meeting 4NF is given.
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This work is supported by Natural Science Foundation of Heilongjiang Province under the project of “Organization of Acyclic Databases”, No.F00-06.
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Zhongxiao, H., Chunlong, Y. The existence condition of γ-acyclic database schemes with MVDs constraints. J. Comput. Sci. & Technol. 17, 517–521 (2002). https://doi.org/10.1007/BF02943293
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DOI: https://doi.org/10.1007/BF02943293