Category Archives: RDBMS Interview Questions

What is 5NF? | RDBMS Questions

A Relation schema R is said to be 5NF if for every join dependency {R1, R2, …, Rn} that holds R, one the following is true ? Ri = R for some i. ? The join dependency is implied by … Continue reading

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What is 4NF? | RDBMS Questions

A relation schema R is said to be in 4NF if for every Multivalued dependency X Y that holds over R, one of following is true ? X is subset or equal to (or) XY = R. ? X is … Continue reading

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What is BCNF (Boyce-Codd Normal Form)? | RDBMS Questions

A relation schema R is in BCNF if it is in 3NF and satisfies an additional constraint that for every FD X A, X must be a candidate key.

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What is 3NF? | RDBMS Questions

A relation schema R is in 3NF if it is in 2NF and for every FD X A either of the following is true ? X is a Super-key of R. ? A is a prime attribute of R. In … Continue reading

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What is 2NF? | RDBMS Questions

A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key.

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What is Fully Functional dependency? | RDBMS Questions

It is based on concept of full functional dependency. A functional dependency X Y is full functional dependency if removal of any attribute A from X means that the dependency does not hold any more.

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What is 1 NF (Normal Form)? | RDBMS Questions

The domain of attribute must include only atomic (simple, indivisible) values.

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What is Lossless join property? | RDBMS Questions

It guarantees that the spurious tuple generation does not occur with respect to relation schemas after decomposition.

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What is Multivalued dependency? | RDBMS Questions

Multivalued dependency denoted by X Y specified on relation schema R, where X and Y are both subsets of R, specifies the following constraint on any relation r of R: if two tuples t1 and t2 exist in r such … Continue reading

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When is a functional dependency F said to be minimal? | RDBMS Questions

? Every dependency in F has a single attribute for its right hand side. ? We cannot replace any dependency X A in F with a dependency Y A where Y is a proper subset of X and still have … Continue reading

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