Made Easy Test Series: Database-Normalization

Question

Consider the relation $R\left ( A,B,C,D,E \right )$ with functional dependencies

$F=${

$A\rightarrow B$

$BC\rightarrow E$

$ED\rightarrow A$

}

Number of additional relation required to convert it into lossless , dependency preserving $3NF$ decomposition is _____________

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What is meaning of additional relation (Here no table mentioned previously)??

Comments

total number of extra table will be zero.it is already in 3NF

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agreed.

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Each and every attribute is prime attribute. so we can say directly the relation is in 3NF.

Answer 1

First, let's have a look at the candidate keys. 

In this case the candidate keys are $\rightarrow$ $CDA$, $CDB$, $CDE$.

Now, in this case, each attribute is a prime attribute. So, this realtion is already in 3NF and there is no point in decomposing this further.

Therefore, no additional relations are required.

So, the correct answer to this question will be 0.

Answer 2

4 table are required.

Comments

how this decomposition is lossless?

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@abhishekmehta4u

ans given 2 tables

Are u sure??

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how does A->B is a voilation of 3NF as B is a prime attribute ?

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Here every attribute is prime so every FD in given table is satisfying X> Y where X is a super key or  Y is prime attribute so is not in 3nf already?