Engineering Questions with Answers - Multiple Choice Questions
Database MCQ – Relational Database and Database Schema
A relational database consists of a collection of
Explanation: Fields are the column of the relation or tables. Records are each row in a relation. Keys are the constraints in a relation.
A ________ in a table represents a relationship among a set of values.
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.
The term _______ is used to refer to a row.
Explanation: Tuple is one entry of the relation with several attributes which are fields.
The term attribute refers to a ___________ of a table.
Explanation: Attribute is a specific domain in the relation which has entries of all tuples.
For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.
Explanation: The values of the attribute should be present in the domain. Domain is a set of values permitted.
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
Explanation: Instance is an instance of time and schema is a representation.
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
Explanation: The relation course has a set of attributes course_id,sec_id,semester .
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
Explanation: Here the relations are connected by the common attributes.
A domain is atomic if elements of the domain are considered to be ____________ units.
The tuples of the relations can be of ________ order.
Explanation: The values only count. The order of the tuples does not matter.