West Bengal Institute of Technology (WBIT) 2008 M.C.A 201 Data Communication & Computer Networks - Question Paper
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CS/MCA/MM-3/MCA-304/M O
ENGINEERING & MANAGEMENT EXAMINATIONS, JUNE - 2008 DATABASE MANAGEMENT SYSTEM > I SEMESTER-2
Time: 3 Hours] [ Full Marks : 70
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GROUP- A
(Multiple Choice Type Questions)
1. Choose the correct alternatives for any ten of the following: ' . 10x1 = 10
i) The set of permitted values for each attribute is called its a) attribute set b) attribute range
c) domain d) group. -
ii) The operation on certain relation X, produces Y such that Y contains only selected attributes of X, such an operation is
a) projection b) selection
c) union d) difference.
iii) A table can be logically connected to another table by defining a a) a hyperlink b) common field
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c) primary key d) foreign key.
iv) DDL stands for a) data-dictionary language b) dictionary defined language
c) data defined language d) data definition language.
v) What Is the cardinality of a table with 000 rows & 10 columns ? a), 10 b) 100
c) 1000 d) 10000.
vi) What operator performs pattern matching in SQL ?
a) except b) intersect *
c) like d) all of these.
vtt) Given relations R (w, x) and $ (y* a). The jresult of 5 ,
SELECT DISTINCT w, x FROM R, S
* is guaranteed to be same as R, If
a) R has no duplicates and S is non-empty
b) R and S have no duplicates '
c) S has no duplicates andT? is ndn-empty
d) R and S have same number of tuples.
viii) R * (A, B, C)
F = {A B
B Q . ,
R is in BCNF
a) True b) False.
ix) . R = (J, K, L)
F = {JK L
L K}
The candidate keys are ...... ,
a) J and K b) JK
c) Only J d) JKandJL.
x) Additional schema for relationship set is essential for
a) many-to-many relationship b) many-to-one relationship
c) one-to-many relationship d) none of these.
xi) An attribute of one table matching the primary key of another table is called as
a) secondary key b) foreign key
c) candidate key d) surrogate key.
xii) Truncate is
a) DDL command b) DML command
c) DCL command d) not at all SQL command.
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3 x5 = 15
GROUP-B (Short Answer Type Questions )
Answer any three of the following.
What la FD ?
1
a)
2.
What is the highest NF of each of the following relations ?
1) R1 (A, B, C) with FDs are A B, A C, C B
j 1 ta
ii) R2 CA, B. C. D) with FDs are A BC, CD B.
b)
4
Define : Super key, candidate key, primary key, foreign key and alternate key.
3.
,
4.
5.
Define entity Integrity and referential Integrity. Explain the difference between them
2 + 3
through example.
rind out closure of attribute set (AG) (AO)* In the relational schema R and set o(
' functional dependencies F as given below :
R (A. B, C, G, H, I)
F- (AB
A C .
CG * H
CG I *
B HJ
. 5
Is (AG) a super key of R ?
Consider the relation given below :
6.
SCHEDULE {Stdld, ClassNo. StdName, StdMajor. ClassTlme, ClassRoom, Instructor)
' Following are functional dependencies of SCHEDULE :
Stdld - StdName - ,
Stdld - StdMajor
ClassNo -ClassTlme ClassNo ClassRoom ClassNo * Instructor
What is the highest normal form of this relation ?
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GROUP-C
(Long Answer Type Questions)
. Answer any three of the following questions. " 3x15 = 45
7. a) Consider a university database for the scheduling of classrooms for final exams.
This database could be modeled as the single entity set exam, with attributes
. course_name, scctlon numbcr, room number and time. Alternatively, one or
more additional entity sets could be defined, along with relationship sets to
replace some of the attributes of the exam entity set, as f *
I) course with attributes name, department and cnumber . "
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II) section with attributes snumber and enrollment and dependent as a week entity set on course. ' ' '
t ill) room with attributes r_number, capacity and building.
Draw an E-R diagram for the above problem.
Reduce the E-R diagram into relational schema by defining all the constraints and assumptions.
b) Explain with example the concept of reducing to relational schema in case . specialization and generalization. - 10 + 5
8. Consider the following relational schema :
EMP (EmpNo, EmpName, City, Sal, DeptNo)
DEPT (DeptNo, DeptName) .
Write down the following queries in SQL ; .5x3
i) Find the names and cities of all employees working for the "Research" department
11) Display the number of employees in each department ,
ill) Display the names of all employees in department number 20 . ,
iv) Find the names of employees who have the second highest salary
v) Find the names of employees whose salary is greater than anyone's salary of department 10.
7MCA/BMM/MCM04/M
9. a) What is the difference between primary and secondary storage ?
b) How does multilevel indexing Improve the efficiency of searching an Index file ?
( I
c) How does B-tree differ from a B+tree ? *
d) Why is a B+tree usually preferred as an access structure to a data file ?
3 + 3 +-5 + 4
10. Consider the following relational schema :
STUDENT (Id, Name)
ENROLLEDIN (Id. Code)
SUBJECT (Code, Lecturer) .
3x5
Write down the following query expressions :
1) Display the names of students enrolled In the subjects having codes cp 1500 or cp 3010. ( Relational Algebra )
U) Display the names of all the students .enrolled In the subjects having codes cp 1500. ( Tuple Relational Calculus )
111) Display the names of students who are taking a subject not taught by Roger-I Relational'Algebra ) .
11. a) What Is a schedule ?
b) What is the difference between conflict equivalence and view equivalence 1
c) Describe the growing phase and shrinking phase with example of the two phase
locking protocol. ' . . t
d) Describe the walt-die and wound-wait protocols for deadlock prevention.
2 + 4 + 4 +5
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