csce520-lect6 - A is a trivial FD if X A is a nontrivial FD...

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Farkas CSCE 520  2 Third Normal Form Modifies BCNF conditions so no need to  decompose in this problem situation An attribute is prime if it is member of any  key  A violates 3NF if and only if X is not a  superkey and also A is not a prime.
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Farkas CSCE 520  3 3NF Conditions A relation is in 3NF if for all FDs X   A in  S +  over R at least one of the followings  hold:
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Unformatted text preview: A is a trivial FD if X A is a nontrivial FD then X is a superkey for schema R Each attribute B in A-X is contained in a candidate key for R Farkas CSCE 520 4 3NF and BCNF BCNF gives Lossless-join No-redundancy Dependency preservation not always possible 3NF gives Lossless-join Dependency preservation May have null values...
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csce520-lect6 - A is a trivial FD if X A is a nontrivial FD...

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