Sr No.	Intension Database	Extension Database
1.	.The intension corresponds to what is specified in the relational schema. The intension thus defines all permissible extensions.	The extension of a given relation is the set of tuples appearing in that relationship at any given instance
2.	The intension of a given relation is independent of time. It is the permanent part of the relationship.	The intension of a given relation is independent of time. It is the permanent part of the relationship.
3.	The intension is a combination of two things: a structure and a set of integrity constraints.	It changes as tuples are created, destroyed, and updated.

Example of Intension Database

Employee (Reg  No.(5) Not NULL, Name Char(20), Age Number (2), Company Char(20))

This is the intension of employee relation.

Example of Extension Database

Relation: Extension of employees at time t₁ when 2 tuples are added-

Reg No.	Name	Age	Company
22501	Sonakshi Sahni	27	Yagesh Export Ltd.
22502	Sneha Sarin	30	Smile Crafters Dental Cooperates

Relation: Extension of employees at time t₂ when 2 more tuples are added and one is updated-

Reg No.	Name	Age	Company
22501	Sonakshi Sahni	27	Yagesh Export Ltd.
22502	Sneha Arora	30	Smile Crafters Dental Cooperates
22504	Rajat Mishra	29	RTF Bank
22509	Varun Kakkar	24	HSM Management