Extraneous Tuples

Question

1) What steps should be followed to remove all extraneous tuples?

If there any good link for this or any book contain good information about it

Comments

no I donot want  lossy, lossless join

Suppose

$A\rightarrow B$

$AB\rightarrow C$

how to eliminate extronious attribute here?

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What i said above is extraneous tuples.

Extraneous Attributes:- Whenever we find Minimal cover of given FD set we remvoe extraneous step(It is one of the step to get minimal cover)

Two types of extraneous attibutes:-

1. $ AB -> C  ,  A-> B $ ,Here B is extraneous attribute in $AB -> C$ ,so remove B from  $AB->C$,we can remove B and rewrite FD's as, $ A->C,A->B $

2. $ AB -> C,  A-> C $ ,Here B is extraneous attribute ,so remove B fom $AB->C$,we can remove B ans rewrite FD's as, $ A->C $

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Other links :- Sanchit Jain sir Techtud