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  • Question 1
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    Consider the following set of functional dependencies F on the schema S(P, Q, R)

    F = {P → QR, PQ → R, Q → R, P → Q}

    The canonical cover of the above given set is 

  • Question 2
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    Which of the following concurrency control protocol ensures both conflict serializability and free from deadlock?

  • Question 3
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    Let the two-relation schema be R (A, B,) and S (A, B). which of the following is not equivalent to R ∩ S

  • Question 4
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    Consider a relation R(X, Y, Z, W) where X, Y, and Z are attributes and the functional dependencies are X → Y and X → Z.

    What is the number of functional dependencies possible with attribute X?

  • Question 5
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    The following table has two attributes X and Y where X is the primary key and Y is the foreign key referencing X with on-delete cascade.

    X

    Y

    2

    4

    3

    4

    4

    3

    5

    2

    7

    2

    9

    5

    6

    4

     

    The set of all tuples that must be additionally deleted to preserve referential integrity when the tuple (3, 4) is deleted is: 

  • Question 6
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    Given two table R1 (x, y) and R2(y, z) with 50 and 30 number of tuples respectively. Find maximum number of tuples in the output of natural join between tables R1 and R2 i.e. R1 * R2? (* - Natural Join)

  • Question 7
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    Consider a B+ tree in which the minimum number of keys in a node is 23. What is the maximum number of keys in any non-root node?

  • Question 8
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    Assume that there are two transactions T1 and T2 of which T1 started execution before T2. Consider the following schedule involving two transactions T1 and T2

    T1:r(A) T2: r(B)  T2:w(A) T1:w(A)

    Which of the following is true about the following schedule

  • Question 9
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    Given below is an instance of the MENTOR relation:

    MentorID

    Name

    Salary

    Age

    Department

    1001

    Priya

    10000

    23

    English

    1002

    Sheenam

    20000

    25

    Maths

    1003

    Priya

    25000

    X

    Maths

    1004

    Renu

    10000

    25

    Science

    1005

    Renu

    12000

    27

    English

     

    For (Name, Age) to be a key for this instance, the value X should not be equal to_________.

  • Question 10
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    If R(ABC) with FDs = AB → C, AC → B, BC → A, then what is the strongest normal form that is not violated by this relation?

  • Question 11
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    Consider the following query :

    SELECT E.eno, COUNT(*)

    FROM Employees E

    GROUP BY E.eno

    If an index on eno is available, the query can be answered by scanning only the index if

  • Question 12
    2 / -0.33

    Consider the relation R = {ABCDEG} and set of FDs are F = {AB → C, AC → B, AD → E, B →D, BC → A, E → G}, then the decomposition {ABC, ACDE, ADG} is 

  • Question 13
    2 / -0.33

    Consider a relation book (title, price) which contains the titles and prices of different books.

    Assuming that no two books have the same price, what does the following SQL query list ?

    Select title

    from book as B

    where (select count (*)

    from book as T

    where T.price > B.price) < 7

  • Question 14
    2 / -0.33

    In a relational schema R(P, Q, R, S, T, V) with functional dependencies are given below:

    P → RS

    R → SV

    S → Q

    T → P

    What is the number of superkey possible in R?

  • Question 15
    2 / -0.33

    Consider the following relation schema R and S along with their tuple sets.

    R(A, B) = {<a1, b1 >, <a2, b1>, <a3, b1>, <a4, b1), <a1, b2>, <a3, b2>, <a2, b3>, <a3, b3>, <a4, b3>, <a1, b4>, <a2, b4>, <a3, b4>}

    S(A) = {a1, a2, a3}

    What is the value of T ← R/S, where “/” represents the Relational Algebra “division” operation?

  • Question 16
    2 / -0.33

    Consider the following tuple relational calculus:

    {t | Ǝ s ε instructor (t[name] = s[name]

        ᴧ Ǝ u ε department (u[dept_name] = s[dept_name]

             ᴧ u[building] = “Taylor”))}

    What does the given expression perform?

  • Question 17
    2 / -0.33

    Database table name Group_A  and Group_B is given below

    Group_A

    Roll_no

    Student_Name

    Age

    10

    X

    18

    15

    Z

    20

    19

    Y

    17

    22

    Z

    19

    89

    Y

    21

    22

    Y

    20

     

    Group_B

    Roll_no

    Student_Name

    Age

    06

    X

    19

    25

    V

    21

    19

    Y

    18

    2

    Z

    20

    22

    W

    17

     

    How many tuples does the result of the following SQL query contain?

    Select Group_A.Roll_no

    FROM Group_A

    Where Group_A.age > All(SELECT Group_B.Age

     FROM Group_B

    where Group_B.Student_Name = ‘Y’)

  • Question 18
    2 / -0.33

    Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values.

    F={CH→G, A→BC, B→CFH, E→A, F→EG} is a set of functional dependencies (FDs) so that F+ is

    exactly the set of FDs that hold for R.

    The relation R is 

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