bytea and uuid

Learning Focus

Use this lesson to understand PostgreSQL binary storage (bytea) and practical UUID patterns.

bytea Overview

bytea stores binary data.

CREATE TABLE file_blobs (
  file_id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  content bytea NOT NULL
);

Prefer object storage for large files; keep bytea for small blobs.

uuid Overview

uuid is a native type for globally unique identifiers.

Generation options:

• gen_random_uuid() via pgcrypto
• uuid_generate_v4() via uuid-ossp

Example:

CREATE EXTENSION IF NOT EXISTS pgcrypto;

CREATE TABLE api_keys (
  api_key_id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  owner_email text NOT NULL
);

What's Next

• Continue to Date and Time Data Types
• Or return to String Data Types Overview