UUID

Use uuid with gen_random_uuid()

uuid16 bytesRecommended

Primary keys in distributed systems, public-facing IDs, merge-safe keys.

Range

128-bit UUID

Performance

Compact 16 bytes (vs 36-char text). Supports btree and hash indexes natively.

Comparison

uuid vs text: uuid type is 16 bytes vs 36+ bytes for text. It validates format on insert and is faster to compare. Use gen_random_uuid() (built-in since PG 13) for v4 UUIDs.

SQL Example

CREATE TABLE accounts (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name text NOT NULL
);