smallint

Learning Focus

Use this lesson to understand PostgreSQL smallint and when it is (and is not) the right choice.

smallint Overview

• Storage: 2 bytes
• Range: -32,768 to 32,767
• Best for: small bounded counters (ratings, small category IDs, short enums represented as integers)

Example

CREATE TABLE product_reviews (
  review_id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  rating smallint NOT NULL CHECK (rating BETWEEN 1 AND 5)
);

Common Pitfalls

Pitfall	Consequence	Prevention
Using smallint for growing IDs	Overflow risk	Use integer or bigint for identifiers

Best Practices

• Use smallint only when you know the value domain is small.
• Enforce the domain with CHECK.

What's Next

• Next: integer
• Section Overview