DBMS GATE CS and IT previous year questions with answer

Ques 21 Gate 2015 Set-3

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Consider the relation X(P, Q, R, S, T, U) with the following set of functional dependencies

F = {
        {P, R} → {S,T},
        {P, S, U} → {Q, R}
}

Which of the following is the trivial functional dependency in F⁺ is closure of F?

A

{P,R}→{S,T}

B

{P,R}→{R,T}

C

{P,S}→{S}

D

{P,S,U}→{Q}

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Ques 22 Gate 2015 Set-3

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Consider the following relation

Cinema (theater, address, capacity)

Which of the following options will be needed at the end of the SQL query

SELECT P1. address FROM Cinema P1

Such that it always finds the addresses of theaters with maximum capacity?

A

WHERE P1. Capacity> = All (select P2. Capacity from Cinema P2)

B

WHERE P1. Capacity> = Any (select P2. Capacity from Cinema P2)

C

WHERE P1. Capacity > All (select max(P2. Capacity) from Cinema P2)

D

WHERE P1. Capacity > Any (select max (P2. Capacity) from Cinema P2)

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Ques 23 Gate 2015 Set-2

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Consider the following transaction involving two bank accounts x and y.

read(x); x := x – 50; write(x); read(y); y := y + 50; write(y)

The constraint that the sum of the accounts x and y should remain constant is that of

A

Atomicity

B

Consistency

C

Isolation

D

Durability

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Ques 24 Gate 2015 Set-1

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A file is organized so that the ordering of data records is the same as or close to the ordering of data entries in some index. Then that index is called

A

Dense

B

Sparse

C

Clustered

D

Unclustered

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Ques 25 Gate 2015 Set-1

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Select operation in SQL is equivalent to

A

the selection operation in relational algebra

B

the selection operation in relational algebra, except that select in SQL retains duplicates

C

the projection operation in relational algebra

D

the projection operation in relational algebra, except that select in SQL retains duplicates

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