MCQ ON “Relational Database and Database Schema”

Database Questions & Answers on “Relational Database and Database Schema”

1. A relational database consists of a collection of
a) Tables
b) Fields
c) Records
d) Keys

Answer:a
Explanation:Fields are the column of the relation or tables.Records are each row in relation.Keys are the constraints in a relation .

2. A ________ in a table represents a relationship among a set of values.
a) Column
b) Key
c) Row
d) Entry

Answer:c
Explanation:Column has only one set of values.Keys are constraints and row is one whole set of attributes.Entry is just a piece of data.

3. The term _______ is used to refer to a row.
a) Attribute
b) Tuple
c) Field
d) Instance

Answer:b
Explanation:Tuple is one entry of the relation with several attributes which are fields.

4. The term attribute refers to a ___________ of a table.
a) Record
b) Column
c) Tuple
d) Key

Answer:b
Explanation:Attribute is a specific domain in the relation which has entries of all tuples.

5. For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.
a) Domain
b) Relation
c) Set
d) Schema

Answer:a
Explanation:The values of the attribute should be present in the domain.Domain is a set of values permitted .

6. Database __________ , which is the logical design of the database, and the database _______,which is a snapshot of the data in the database at a given instant in time.
a) Instance, Schema
b) Relation, Schema
c) Relation, Domain
d) Schema, Instance

Answer:d
Explanation:Instance is a instance of time and schema is a representation.

7.Course(course_id,sec_id,semester)
Here the course_id,sec_id and semester are __________ and course is a _________ .
a) Relations, Attribute
b) Attributes, Relation
c) Tuple, Relation
d) Tuple, Attributes

Answer:b
Explanation:The relation course has a set of attributes course_id,sec_id,semester .

8. Department (dept name, building, budget) and Employee (employee_id , name, dept name,salary)
Here the dept_name attribute appears in both the relations .Here using common attributes in relation schema is one way of relating ___________ relations.
a) Attributes of common
b) Tuple of common
c) Tuple of distinct
d) Attributes of distinct

Answer:c
Explanation:Here the relations are connected by the common attributes.

9. A domain is atomic if elements of the domain are considered to be ____________ units.
a) Different
b) Indivisbile
c) Constant
d) Divisible

Answer:b
Explanation:None.

10. The tuples of the relations can be of ________ order.
a) Any
b) Same
c) Sorted
d) Constant

Answer:a
Explanation:The values only count .The order of the tuples does not matter.