Database Systems MCQ

 Q.1 Which of the following is correct:
(A) a SQL query automatically eliminates duplicates.
(B) SQL permits attribute names to be repeated in the same relation.
(C) a SQL query will not work if there are no indexes on the relations
(D) None of these
Ans: D

Q.2 It is better to use files than a DBMS when there are
(A) Stringent real-time requirements.
(B) Multiple users wish to access the data.
(C) Complex relationships among data.
(D) All of the above.
Ans: B

Q.3 The conceptual model is
(A) dependent on hardware.
(B) dependent on software.
(C) dependent on both hardware and software .
(D) independent of both hardware and software.
Ans: D

Q.4 What is a relationship called when it is maintained between two entities?
(A) Unary
(B) Binary
(C) Ternary
(D) Quaternary
Ans: B

Q.5 Which of the following operation is used if we are interested in only certain columns of a table?
(A) PROJECTION
(B) SELECTION
(C) UNION
(D) JOIN
Ans: A

Q.6 Which of the following is a valid SQL type?
(A) CHARACTER
(B) NUMERIC
(C) FLOAT
(D) All of the above
Ans: D

Q.7 The RDBMS terminology for a row is
(A) tuple.
(B) relation.
(C) attribute.
(D) degree.
Ans: A

Q.8 Which of the following operations need the participating relations to be union compatible?
(A) UNION
(B) INTERSECTION
(C) DIFFERENCE
(D) All of the above
Ans: D

Q.9 The full form of DDL is
(A Dynamic Data Language
(B) Detailed Data Language
(C) Data Definition Language
(D) Data Derivation Language
Ans: C

Q.10 Which of the following is an advantage of view?
(A) Data security
(B) Derived columns
(C) Hiding of complex queries
(D) All of the above
Ans: D

Q.11 Which of the following is a legal expression in SQL?
(A) SELECT NULL FROM EMPLOYEE;
(B) SELECT NAME FROM EMPLOYEE;
(C) SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL;
(D) None of the above
Ans: B

Q.12 The users who use easy-to-use menu are called
(A) Sophisticated end users.
(B) Naïve users.
(C) Stand-alone users.
(D) Casual end users.
Ans: B

Q.13 Which database level is closest to the users?
(A) External
(B) Internal
(C) Physical
(D) Conceptual
Ans: A

Q.14 Which are the two ways in which entities can participate in a relationship?
(A) Passive and active
(B) Total and partial
(C) Simple and Complex
(D) All of the above
Ans: B

Q.15 The result of the UNION operation between R1 and R2 is a relation that includes
(A) all the tuples of R1
(B) all the tuples of R2
(C) all the tuples of R1 and R2
(D) all the tuples of R1 and R2 which have common columns
Ans: D

Q.16 Which of the following is a comparison operator in SQL?
(A) =
(B) LIKE
(C) BETWEEN
(D) All of the above
Ans: D

Q.17 A set of possible data values is called
(A) attribute.
(B) degree.
(C) tuple.
(D) domain.
Ans: D

Q.18 Which of the operations constitute a basic set of operations for manipulating relational data?
(A) Predicate calculus
(B) Relational calculus
(C) Relational algebra
(D) None of the above
Ans:C

Q.19 Which of the following is another name for weak entity?
(A) Child
(B) Owner
(C) Dominant
(D) All of the above
Ans: A

Q.20 Which of the following database object does not physically exist?
(A) base table
(B) index
(C) view
(D) none of the above
Ans: C

Q.21 NULL is
(A) the same as 0 for integer
(B) the same as blank for character
(C) the same as 0 for integer and blank for character
(D) not a value
Ans: D

Q.22 Which of the following is record based logical model?
(A) Network Model
(B) Object oriented model
(C) E-R Model
(D) None of these
Ans: A

Q.23 A data dictionary is a special file that contains:
(A) The name of all fields in all files.
(B) The width of all fields in all files.
(C) The data type of all fields in all files.
(D) All of the above.
Ans: D

Q.24 A file manipulation command that extracts some of the records from a file is called
(A) SELECT
(B) PROJECT
(C) JOIN
(D) PRODUCT
Ans: A

Software Engineering

1. Software Engineering primarily aims on
a. Reliable software
b. Cost effective software
c. Reliable and cost effective software
d. Non of the above

2. A good specification should be
a. Unambiguous
b. Distinctly specific
c. Functional
d. None of the above

3. Which of the following is a tool in design phase?
a. Abstraction
b. Refinement
c. Information hiding
d. None of the above

4. In object oriented design of software, which of the following is not true?
a. Objects inherit the properties of the class
b. Classes are defined based on the attributes of objects
c. An object can belong to two classes
d. Classes are always different

5. Information hiding is to hide from user, details
a. That are relevant to him
b. That are irrelevant to him
c. That may be maliciously handled by him
d. That are confidential

6. Design phase includes
a. Data, architectural and procedural designs only
b. Architectural, procedural and interface designs only
c. Data, architectural and interface designs only
d. Data, architectural, interface and procedural designs

7. Data structure suitable for the application is discussed in
a. Data design
b. Architectural design
c. Procedural design
d. Interface design

8. Design phase will usually be
a. Top-down
b. Bottom-up
c. Random
d. Centre fringing

9. Assertions are conditions which are true at the point of execution
a. Always
b. Sometimes
c. Many times
d. No time

10. Assuming the existence of a start and end nodes for a program graph (PG), the total number of paths is equivalent to ________________ set of test data required to test software.
a. Minimum
b. Maximum
c. Optimum
d. Supremum

11. In a program graph (PG), if X is a if-then-else node and the number of paths from if part to end node is y and for else part is Z with the number of paths from strat node to end node is x, the total number of paths through X is
a. xy+z
b. xz+y
c. x+y+z
d. x(y+z)

12. If X is a case statement in a program graph (PG) with n cases instead of an if-then-else statement in the previous question with each case leading to only one path to end node, total number of paths through X is
a. x+n
b. x**n
c. x*log(n)
d. x*n

13. Structured programming codes include
a. Sequencing
b. Alteration
d. Multiple exit from loops

14. Which of the following is a desirable property of module?
a. Independency
b. Low cohesiveness
c. High coupling
d. Multifunctional

15. Which of the following types of maintenance takes the maximum chunk of the total maintenance effort in a typical commercial application environment?
a. Adaptive maintenance
b. Corrective maintenance
c. Preventive maintenance
d. Perfective maintenance

16. An important aspect in coding is
a. Readability
b. Productivity
c. To use as small memory space as possible
d. Brevity

17. One way to improve readability in coding is to
a. Avoid goto statement
b. Name variables and functions according to their use
c. Modularize the program
d. None of the above

18. The data flow model of an application mainly shows
a. The underlying data and the relationship among them
b. Processing requirements and he flow of the data
c. Decision and control information
d. Communication network structure

19. According to Brooks, if n is the number of programmers in a project team then the number of communication path is
a. n*(n-1)/2
b. n*log(n)
c. n
d. n*(n+1)/2

20. The extent to which the software can continue to operate correctly despite the introduction of invalid input is called as
a. Reliability
b. Robustness
c. Fault-tolerance
d. Portability

21. Which of the following statements is not true?
a. Content coupling in a module is desirable
b. Logical cohesion in a module is desirable
c. Stamp coupling is preferred over functional coupling
d. None of the above

22. Configuration management is not concerned with
a. Controlling changes to the source code
b. Choice of hardware configuration for an application
c. Controlling documentation changes
d. Maintaining versions of software

23. The railway reservation system currently operational in India can be classified as a
a. Batch processing system
b. Real-time system
c. Online system
d. Expert system

24. Data flow diagram, regular expression and transition table can be combined to provide __________________ for functional specification OS system software
a. Decision table
b. Finite state automata
c. Event table
d. None of the above

25. A program P calls two subprograms P1 and P2. P1 can fail 50% times and P2 40% times P can fail
a. 50%
b. 60%
c. 10%
d. 70%

26. Which of the following graph theoretic concept will be useful in software testing?
a. Cyclomatic number
b. Hamiltonian circuit
c. Eularian cycle
d. None of the above

27. In a decision table if there are 3 variables and 3 rules, implies
a. Specification may not be complete
b. Design could be faulty
c. Coding will be incorrect
d. All of the above

28. In unit testing of a module, it is found for a set of test data, at the maximum 90% of the code alone were tested with the probability of success 0.9. the reliability of the module is
a. Atleast greater than 0.9
b. Equal to 0.9
c. Atmost 0.81
d. Atleast 1/0.81

29. Which of the following testing methods is normally used as the acceptance test for a software system?
a. Regression testing
b. Integration testing
c. Unit testing
d. Functional testing

30. A computer program can often be a very satisfactory __________________ of a physical system such as road traffic conditions
a. Solution
b. Replacement
c. Stimulation
d. Model

31. On an average, the programmer months is given by 3.6*(KDSI)**1.2. If so, a project requiring one thousand source instruction will require
a. 3.6 PM
b. 0.36PM
c. 0.0036PM
d. 7.23PM

32. Considering a program graph(PG) with statement as vertices and control as edges, which of the following is not true for any program graph
a. PG is always acyclic
b. PG is always a directed graph
c. There won’t be any self loops
d. PG is always a connected graph

33. In object-oriented design of software, objects have
a. Attributes and name only
b. Operations and name only
c. Attributes, name and operations
d. None of the above
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