Vol. I · A Postgres Handbook

The Query & the Schema

A reading-room reference for writing PostgreSQL by hand — selects to window functions, with the schema in plain view.

IntermediateBasic SELECT

Using UUIDs

The query

SQL
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

CREATE TABLE devices (
  device_id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  device_name TEXT
);
Tested against PostgreSQL 16

Note

“UUIDs are great for distributed systems to avoid ID collisions. uuid_generate_v4() generates random UUIDs.