View vs Materialised Views in PostgreSQL

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This is the most commonly asked interview question. In this article, I will cover all the possible questions that may be asked in a SQL Developer Interview.

What is a View?

A view in a database is a virtual table that is based on the result set of an SQL query. Views are used to simplify complex queries, enhance security, and present data in a specific format.

We have two tables: Orders and Returns

orders

returns

create view vw_orders as
SELECT o.*, r.return_date FROM orders o left join 
returns r on o.order_id = r.order_id

Output From The View

--Insert one row:
INSERT INTO orders values(12,'2023–01–21','Laptop', 15000000)