Database Systems MCQ

 Q.1 The cost of reading and writing temporary files while evaluating a query can be reduced by

(A) building indices 

(B) pipelining

(C) join ordering 

(D) none of the above

Ans: (B)

Q.2 A transaction is in __________ state after the final statement has been executed.

(A) partially committed 

(B) active

(C) committed 

(D) none of the above

Ans: (C)

Q.3 In multiple granularity of locks SIX lock is compatible with

(A) IX 

(B) IS

(C) S 

(D) SIX

Ans: (B)

Q.4 The statement that is executed automatically by the system as a side effect of the modification of the database is

(A) backup 

(B) assertion

(C) recovery 

(D) trigger

Ans: (D)

Q.5 The normal form that is not necessarily dependency preserving is

(A) 2NF 

(B) 3NF

(C) BCNF 

(D) 4NF

Ans: (A)

Q.6 A functional dependency of the form x -> y is trivial if

(A) y Í x 

(B) y Ì x

(C) x Í y 

(D) x Ì y

Ans: (A)

Q.7 The normalization was first proposed by ______________.

(A) Code 

(B) Codd

(C) Boyce Codd 

(D) Boyce

Ans: (B)

Q.8 The division operator divides a dividend A of degree m+n by a divisor relation B of

degree n and produces a result of degree

(A) m – 1 

(B) m + 1

(C) m * m 

(D) m

Ans: (D)

Q.9 Which of the following is not a characteristic of a relational database model?

(A) Table 

(B) Tree like structure

(C) Complex logical relationship 

(D) Records

Ans: (B)

Q.10 Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R.

(A) It will result in a deadlock situation.

(B) It will immediately be rejected.

(C) It will immediately be granted.

(D) It will be granted as soon as it is released by A .

Ans: (C)

Q.11 In E-R Diagram total participation is represented by

(A) double lines 

(B) Dashed lines

(C) single line 

(D) Triangle

Ans: (A)

Q.12 The FD A -> B , DB -> C implies

(A) DA -> C 

(B) A -> C

(C) B -> A 

(D) DB -> A

Ans: (A)

Q.13 The graphical representation of a query is ________.

(A) B-Tree 

(B) graph

(C) Query Tree 

(D) directed graph

Ans: (C)

Q.14 Union operator is a :

(A) Unary Operator 

(B) Ternary Operator

(C) Binary Operator 

(D) Not an operator

Ans: (C)

Q.15 Relations produced from an E-R model will always be

(A) First normal form. 

(B) Second normal form.

(C) Third normal form. 

(D) Fourth normal form.

Ans: (A)

Q.16 Manager salary details are hidden from the employee .This is

(A) Conceptual level data hiding.

(B) External level data hiding.

(C) Physical level data hiding.

(D) None of these.

Ans: (A)

Q.17 Which of the following is true for network structure?

(A) It is a physical representation of the data.

(B) It allows many to many relationship.

(C) It is conceptually simple.

(D) It will be the dominant database of the future.

Ans: (A)

Q.18 Which two files are used during operation of the DBMS?

(A) Query languages and utilities

(B) DML and query language

(C) Data dictionary and transaction log

(D) Data dictionary and query language

Ans: (C )

Q.19 A list consists of last names, first names, addresses and pin codes. If all people in the list have the same last name and same pin code a useful key would be

(A) the pin code

(B) the last name

(C) the compound key first name and last name

(D) Tr from next page

Ans: (C )

Q.20 In b-tree the number of keys in each node is ____ than the number of its children.

(A) one less 

(B) same

(C) one more 

(D) half

Ans: (A)

Q.21 The drawback of shadow paging technique are

(A) Commit overhead 

(B) Data fragmentation

(C) Garbage collection 

(D) All of these

Ans: (D)

Q.22 Which normal form is considered adequate for normal relational database design?

(A) 2NF 

(B) 5NF

(C) 4NF 

(D) 3NF

Ans: (D)

Q.23 Which of the following addressing modes permits relocation without any change over in the code?

(A) Indirect addressing 

(B) Indexed addressing

(C) PC relative addressing 

(D) Base register addressing

Ans: (B)

Q.24 In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by

(A) jamming 

(B) password

(C) documentation 

(D) record lock

Ans: (D)

Q.25 The values of the attribute describes a particular_____________

(A) Entity set 

(B) File

(C) Entity instance 

(D) Organization

Ans: (C)