UUID Functions

This page provides reference information for the UUID-related functions in Databend. These functions generate and work with Universally Unique Identifiers (UUIDs).

UUID Generation Functions

Function	Description	Example
GEN_RANDOM_UUID	Generates a random UUID (version 7 from v1.2.658, version 4 before)	GEN_RANDOM_UUID() → '01890a5d-ac96-7cc6-8128-01d71ab8b93e'
UUID	Alias for GEN_RANDOM_UUID	UUID() → '01890a5d-ac96-7cc6-8128-01d71ab8b93e'

Usage Examples

Generating Primary Keys

-- Create a table with UUID primary key
CREATE TABLE users (
  id UUID DEFAULT GEN_RANDOM_UUID(),
  username VARCHAR,
  email VARCHAR,
  PRIMARY KEY(id)
);

-- Insert data without specifying UUID
INSERT INTO users (username, email) 
VALUES ('johndoe', 'john@example.com');

-- Query to see the auto-generated UUID
SELECT * FROM users;

Creating Unique Identifiers for Distributed Systems

-- Generate multiple UUIDs for distributed event tracking
SELECT 
  GEN_RANDOM_UUID() AS event_id,
  'user_login' AS event_type,
  NOW() AS event_time
FROM numbers(5);

UUID Version Information

Databend's UUID implementation has evolved:

• Version 1.2.658 and later: Uses UUID version 7, which includes timestamp information for chronological sorting
• Prior to version 1.2.658: Used UUID version 4, which was purely random