What is a temporary table and what is it used for?

A temporary table is a special type of data table in relational databases that stores an intermediate set of data for one-time use or during a single session.

It is used for:

• Storing intermediate results of complex queries to avoid re-executing the same calculations.
• Improving query performance by working with a smaller volume of data.
• Simplifying the logic of complex SQL operations by breaking them into smaller steps.
• Working with data specific to the current session or transaction.

After the session or transaction ends, the temporary table and its data are automatically deleted. The creation syntax may vary depending on the database management system (DBMS). For example, in PostgreSQL:

-- Creating a temporary table
CREATE TEMP TABLE my_temp_table (
    id INT,
    name VARCHAR(50)
);

-- Inserting data
INSERT INTO my_temp_table (id, name) VALUES (1, 'Test');

-- Selecting data
SELECT * FROM my_temp_table;