pg_slug_gen

pg_slug_gen : Generate cryptographically secure timestamp-based slugs

Overview

Packages

Source

pig build pkg pg_slug_gen;		# build rpm/deb

Install

Make sure PGDG and PIGSTY repo available:

pig repo add pgsql -u   # add both repo and update cache

Install this extension with pig:

pig install pg_slug_gen;		# install via package name, for the active PG version

pig install pg_slug_gen -v 18;   # install for PG 18
pig install pg_slug_gen -v 17;   # install for PG 17
pig install pg_slug_gen -v 16;   # install for PG 16
pig install pg_slug_gen -v 15;   # install for PG 15

Create this extension with:

CREATE EXTENSION pg_slug_gen;

Usage

Sources: official PGXN release page, official release README, official release SQL, official release metadata

pg_slug_gen generates timestamp-based slugs with cryptographic randomness. The official 1.0.0 release describes it as a secure, URL-friendly short ID generator where the requested length selects the timestamp precision.

CREATE EXTENSION pg_slug_gen;

SELECT gen_random_slug();
SELECT gen_random_slug(13);

Function

• gen_random_slug(slug_length int DEFAULT 16) returns text

The release SQL comment and README document these supported values:

• 10: seconds
• 13: milliseconds
• 16: microseconds, also the default
• 19: nanoseconds

Precision And Format

Each precision maps to a timestamp width and a fixed slug shape:

• 10 digits: 5-5 format, 11 characters total
• 13 digits: 6-7 format, 14 characters total
• 16 digits: 8-8 format, 17 characters total
• 19 digits: 9-10 format, 20 characters total

The README states the collision-free window is bounded by timestamp precision: at most 1 insert per second, millisecond, microsecond, or nanosecond respectively.

Examples

SELECT gen_random_slug();
SELECT gen_random_slug(10);
SELECT gen_random_slug(16);

CREATE TABLE products (
  id serial PRIMARY KEY,
  name text NOT NULL,
  slug text DEFAULT gen_random_slug() UNIQUE
);

How It Works

The official README describes this algorithm:

• take the current timestamp at the chosen precision
• map each digit to a QWERTY-based character bucket
• choose one random character from that bucket with pg_strong_random()
• insert a hyphen at the midpoint

Caveats

• This is a secure short-ID generator, not a text transliteration or title-to-URL slugifier.
• Same-timestamp collisions are still possible; upstream only claims uniqueness when inserts do not exceed one per chosen time unit.
• The official release metadata still points to https://github.com/fernandoolle/pg_slug_gen, but that repo URL currently returns 404.