MCQ On Database Design With Answer Set-1

This set of MCQ questions includes objective type questions on database design along with answer of each. It includes MCQ questions about data integrity, entity integrity, types of entity, join and natural join.

1) What is a data integrity?
A. It is the data contained in the database that is non-redundant.
B. It is the data contained in the database that is accurate and consistent.
C. It is the data contained in the database that is secured.
D. It is the data contained in the database that is shared.

2) As per equivalence rules for query transformation, selection operation distributes over
A. Union
B. Intersection
C. Set difference
D. All of the above

3) 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

4) Which of the following relational algebraic operations is not from set theory?
A. Union
B. Intersection
C. Cartesian Product
D. Select

5) An entity set that does not have sufficient attributes to form a primary key is a
A. strong entity set
B. weak entity set
C. simple entity set
D. primary entity set

6) In the case of entity integrity, the primary key may be
A. not Null
B. Null
C. both Null and not Null
D. any value

7) A logical schema
A. is the entire database.
B. is a standard way of organizing information into accessible parts.
C. describes how data is actually stored on disk
D. both A and C

8) 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

9) Which of the following is another name for the weak entity?
A. Child
B. Owner
C. Dominant
D. All of the above

10) Which of the following is a record based logical model?
A. Network Model
B. Object-oriented model
C. E-R model
D. None of the above

11) A file manipulation command that extracts some of the records from a file is called
A. SELECT
B. PROJECT
C. JOIN
D. PRODUCT

12) In E-R Diagram derived attribute is represented by
A. Ellipse
B. Dashed ellipse
C. Rectangle
D. Triangle

13) The natural join is equal to
A. Cartesian Product
B. Combination of Union and Cartesian product
C. Combination of selection and Cartesian product
D. Combination of projection and Cartesian product

14) In E-R diagram relationship type is represented by
A. Ellipse
B. Dashed ellipse
C. Rectangle
D. Diamond

15) In E-R diagram generalization is represented by
A. Ellipse
B. Dashed ellipse
C. Rectangle
D. Triangle

16) A table joined with itself is called
A. Join
B. Self Join
C. Outer Join
D. Equi Join

17) ……….. means multiple copies of the same data items.
A. Data reduction
B. Data integrity
C. Data consistency
D. Data redundancy

18) Different values for the same data item is referred to as …….
A. data consistency
B. data inconsistency
C. data integrity
D. data duplication

19) The ………. returns row after combining two tables based on common values.
A. difference
B. product
C. join
D. union

20) The ………. can be used to ensure database integrity.
A. entity integrity
B. database constraints
C. referential integrity
D. cardinality

Answers:

1) B. It is the data contained in the database that is accurate and consistent.
2) All of the above
3) A. inner join
4) D. Select
5) B. weak entity set
6) A. not Null
7) A. is the entire database.
8) C. Relational algebra
9) Child
10) A. Network Model
11) A. SELECT
12) B. Dashed ellipse
13) D. Combination of projection and Cartesian product
14) D. Diamond
15) D. Triangle
16) B. Self Join
17) D. Data redundancy
18) B. data inconsistency
19) C. join
20) B. database constraints