PDF Database Systems multiple choices questions and answers[PDF]
Q.16 In an E-R diagram double lines indicate
(A) Total participation. (B) Multiple participation.
(C) Cardinality N. (D) None of the above.
Ans: (A)
Q.17 The operation which is not considered a basic operation of relational algebra is
(A) Join. (B) Selection.
(C) Union. (D) Cross product.
Ans: (A)
Q.18 Fifth Normal form is concerned with
(A) Functional dependency. (B) Multivalued dependency.
(C) Join dependency. (D) Domain-key.
Ans: (C)
Q.19 Block-interleaved distributed parity is RAID level
(A) 2. (B) 3
(C) 4. (D) 5.
Ans: (D)
Q.20 Immediate database modification technique uses
(A) Both undo and redo. (B) Undo but no redo.
(C) Redo but no undo. (D) Neither undo nor redo.
Ans: (A)
Q.21 In SQL the statement select * from R, S is equivalent to
(A) Select * from R natural join S. (B) Select * from R cross join S.
(C) Select * from R union join S. (D) Select * from R inner join S.
Ans: (B)
Q.22 Which of the following is not a consequence of concurrent operations?
(A) Lost update problem. (B) Update anomaly.
(C) Unrepeatable read. (D) Dirty read.
Ans: (B)
Q.23 As per equivalence rules for query transformation, selection operation distributes over
(A) Union. (B) Intersection.
(C) Set difference. (D) All of the above.
Ans: (D)
Q.24 The metadata is created by the
(A) DML compiler (B) DML pre-processor
(C) DDL interpreter (D) Query interpreter
Ans: (C)
Q.25 When an E-R diagram is mapped to tables, the representation is redundant for
(A) weak entity sets (B) weak relationship sets
(C) strong entity sets (D) strong relationship sets
Ans: (B)
Q.26 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.27 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.28 The default level of consistency in SQL is
(A) repeatable read (B) read committed
(C) read uncommitted (D) serializable
Ans: (D)
Q.29 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.30 Shadow paging has
(A) no redo (B) no undo
(C) redo but no undo (D) neither redo nor undo
Ans: (A)
PDF Database Systems multiple choices questions and answers
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