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I know how to calculate a minimal cover-- ensure each functional dependency only has one attribute on the RHS, remove extraneous/redundant LHS attributes by calculating the closure of each, examining all FD's, seeing if any can be removed (again by calculating a closure).

Is 'canonical' cover just another word for the same thing?

philipxy
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Mitch
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4 Answers4

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A canonical cover is "allowed" to have more than one attribute on the right hand side. A minimal cover cannot. As an example, the canonical cover may be "A -> BC" where the minimal cover would be "A -> B, A -> C". That is the only difference.

user3282136
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These are the same.

The goal in calculating the canonical is to provide a minimum, in matters of redundancy.

Canonical

philipxy
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sealz
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A canonical cover is the minimal FDs from the closure set. The main reason for a canonical closure is to ensure that there are no redundant dependencies in our database.

philipxy
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divya
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canonical cover and minimal cover both are very close to each other basic difference is in canonical cover you can have more than one attribute at right hand side but in minimal cover you can have only one,rest everything is same aim of both cover is to have remove redundant dependencies from our database.

Raja Rishabh Singh
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