Question

Calculate the degree and cardinality of the given relation below: 

ID	Name	Email	Address	Phone No.
001	Ajay	ajay@abc.com	A1-Shakti Nagar, Bangalore	55218936
002	Amit	amit@abc.com	C32-Indira Nagar, Lucknow	45321789
003	Ashu	ashu@abc.com	117/82 Patel Nagar, Delhi	98567894
004	Ashok	ashok@abc.com	249-250, Motinagar, Gujrat	97698541

• A. Degree = 4, Cardinality = 5
• B. Degree = 5, Cardinality = 4
• C. Degree = 5, Cardinality = 1
• D. Degree = 4, Cardinality = 1

Hint:

Easy mnemonic:
Degree = Number of Columns (Attributes).
Cardinality = Number of Rows (Tuples).
Do not count the header row in cardinality!

Answer 1

The Correct Option is B

Concept:
In relational database terminology:
- The Degree of a table (relation) is the total number of attributes (columns) present in that relation.
- The Cardinality of a relation is the total number of tuples (rows or records) stored in the relation, excluding the attribute header row.

Step 1: Calculating the Degree:
Count the vertical columns defined in the table:
1. ID
2. Name
3. Email
4. Address
5. Phone No.
Total number of attributes = 5.
Therefore, \(\text{Degree} = 5\).

Step 2: Calculating the Cardinality:
Count the distinct data rows (tuples) present:
1. Record of Ajay (ID 001)
2. Record of Amit (ID 002)
3. Record of Ashu (ID 003)
4. Record of Ashok (ID 004)
Total number of tuples = 4.
Therefore, \(\text{Cardinality} = 4\).
Final Answer:
The relation has a Degree of 5 and a Cardinality of 4. This matches option (B).