3NF分解过程 3NF如何分解 (伪代码)

2019-05-25 09:44:52 浏览数 (1)

3NF 分解过程 (伪代码)

  • let Fc be the canonical cover(最小函数依赖集) for F, i = 0
  • for each FD α → β Fc do
    • if (none of Rj , j = 1, 2, . . . , i contains αβ) then
      • i
      • Ri = αβ
  • if (none of Rj , j = 1, 2, . . . , i contains a candidate key for R) then
    • i
    • Ri = any candidate key for R
  • return (R1, R2, . . . , Ri)

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