Q.1 When R , then the
cost of computing ∩S = φ R >< S is
(A) the same as R × S
(B) greater the R × S
(C) less than R × S
(D) cannot say anything
Ans: (A)
Q.2 In SQL the word
‘natural’ can be used with
(A) inner join
(B) full outer join
(C) right outer join
(D) all of the above
Ans: (A)
Q.3 The default level
of consistency in SQL is
(A) repeatable read
(B) read committed
(C) read uncommitted
(D) serializable
Ans: (D)
Q.4 If a transaction
T has obtained an exclusive lock on item Q, then T can
(A) read Q
(B) write Q
(C) both read and write Q
(D) write Q but not read Q
Ans: (C)
Q.5 Shadow paging has
(A) no redo
(B) no undo
(C) redo but no undo
(D) neither redo nor undo
Ans: (A)
Q.6 If the closure of
an attribute set is the entire relation then the attribute set is a
(A) superkey
(B) candidate key
(C) primary key
(D) not a key
Ans: (A)
Q.7 DROP is a
______________ statement in SQL.
(A) Query
(B) Embedded SQL
(C) DDL
(D) DCL
Ans: (C)
Q.8 If two relations
R and S are joined, then the non matching tuples of both R and S are ignored in
(A) left outer join
(B) right outer join
(C) full outer join
(D) inner join
Ans: (D)
Q.9 The keyword to
eliminate duplicate rows from the query result in SQL is
(A) DISTINCT
(B) NO DUPLICATE
(C) UNIQUE
(D) None of the above
` Ans: (C)
Q.10 In 2NF
(A) No functional dependencies (FDs) exist.
(B) No multivalued dependencies (MVDs) exist.
(C) No partial FDs exist.
(D) No partial MVDs exist.
Ans: (C)
Q.11 Which one is
correct statement? Logical data independence provides following without
changing application programs:
(i) Changes in access methods.
(ii) Adding new entities in database
(iii) Splitting an existing record into two or more records
(iv) Changing storage medium
(A) (i) and (ii)
(B) (iv) only,
(C) (i) and (iv)
(D) (ii) and (iii)
Ans: (D)
Q.12 In an E-R, Y is
the dominant entity and X is a subordinate entity. Then which of the following
is incorrect :
(A) Operationally, if Y is deleted, so is X
(B) existence is dependent on Y.
(C) Operationally, if X is deleted, so is Y.
(D) Operationally, if X is deleted, & remains the same.\
Ans: (C)
Q.13 Relational
Algebra is
(A) Data Definition Language .
(B) Meta Language
(C) Procedural query Language
(D) None of the above
Ans: (C)
Q.14 Which of the
following aggregate functions does not ignore nulls in its results?.
(A) COUNT .
(B) COUNT (*)
(C) MAX
(D) MIN
Ans: (B)
Q.15 R (A,B,C,D) is a
relation. Which of the following does not have a lossless join dependency
preserving BCNF decomposition
(A) AB, BCD
(B) AB, BC, CD .
(C) ABC, CAD
(D) ABCD
Ans: (D)
Q.16 Consider the
join of relation R with a relation S. If R has m tuples and S has n tuples,
then the maximum and minimum size of the join respectively are
(A) m+n and 0
(B) m+n and |m-n|
(C) mn and 0
(D) mn and m+n
Ans: (C)
Q.17 Maximum height
of a B+ tree of order m with n key values is
(A) Logm(n)
(B) (m+n)/2
(C) Logm/2(m+n)
(D) None of these
Ans: (D)
Q.18 Which one is
true statement :
(A) With finer degree of granularity of locking a high degree of concurrency is possible.
(B) Locking prevents non – serializable schedules.
(C) Locking cannot take place at field level.
(D) An exclusive lock on data item X is granted even if a shared lock is already
held on X.
Ans: (A)
Q.19 Which of the
following statement on the view concept in SQL is invalid?
(A) All views are not updateable
(B) The views may be referenced in an SQL statement whenever tables are referenced.
(C) The views are instantiated at the time they are referenced and not when they are defined.
(D) The definition of a view should not have GROUP BY clause in it.
Ans: (D)
Q.20 Which of the
following concurrency control schemes is not based on the serializability
property?
(A) Two – phase locking
(B) Graph-based locking
(C) Time-stamp based locking
(D) None of these .
Ans: (D)
Q.21 Which of the
following is a reason to model data?
(A) Understand each user’s perspective of data
(B) Understand the data itself irrespective of the physical representation
(C) Understand the use of data across application areas
(D) All of the above
Ans: (D)
Q.22 If an entity can
belong to only one lower level entity then the constraint is
(A) disjoint
(B) partial
(C) overlapping
(D) single
Ans: (B)
Q.23 The common
column is eliminated in
(A) theta join
(B) outer join
(C) natural join
(D) composed join
Ans: (C )
Q.24 In SQL, testing
whether a subquery is empty is done using
(A) DISTINCT
(B) UNIQUE
(C) NULL
(D) EXISTS
Ans: (D)
Q.25 Use of UNIQUE
while defining an attribute of a table in SQL means that the attribute values
are
(A) distinct values
(B) cannot have NULL
(C) both (A) & (B)
(D) same as primary key
Ans: (C)
