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Consider a relation R with more than two attributes. Let A and B are sets of attributes from R and A$\cap$B = $\phi$. Functional dependency A → B holds on R. Which one of the following can be a correct possible situation for R?

  1. A and B contain prime and non-prime attributes respectively and R is in 2NF as highest normal form
  1. A and B contain prime and non-prime attributes respectively and R is in 3NF as highest normal form
  1. A and B contain non-prime and prime attributes respectively and R is in 3NF as highest normal form.
  1. A and B contain prime attributes and R is in BCNF as highest normal form.

The question in from made easy test series.

The answer is option C.

Doubt 1: In the question it is given that functional dependency A → B holds on R, so do we need to assume that all the functional dependencies holding on R are of type A → B such that A$\cap$B = $\phi$?

 

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what it means that A and B contain prime and non-prime attributes respectively. 

1-Does it means that A has only prime attributes? and B contains only non-prime attributes?

2 – Or it means that both A and B have prime and non-prime attributes?

@Chaitanya Kale Plz look at it.

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I think A and B contain prime and non-prime attributes respectively means that A only has prime attributes and B only contains non-prime attributes
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1 Answer

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just hv to think tht in option C,

if RHS is prime attributes so it will be 3NF (in definition of 3NF)

while if we check other options then there is no surity that it’s given normal form is r8 or not .

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Yes the answer is option C but my doubt is different. Please read my doubt.
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