Contents

• pg_uuidv7: Use the new v7 UUIDs in Postgres
  • Background
  • Quickstart
  • Build
    • Build locally
    • Build using Docker
  • Test
  • Contributing

pg_uuidv7: Use the new v7 UUIDs in Postgres

A tiny Postgres extension to create valid version 7 UUIDs in Postgres.

These are regular Postgres UUIDs, so they can be used as primary keys, converted to and from strings, included in indexes, etc:

SELECT uuid_generate_v7();

           uuid_generate_v7           
--------------------------------------
 018570bb-4a7d-7c7e-8df4-6d47afd8c8fc
(1 row)

The timestamp component of these UUIDs can be extracted:

SELECT uuid_v7_to_timestamptz('018570bb-4a7d-7c7e-8df4-6d47afd8c8fc');
   uuid_v7_to_timestamptz
----------------------------
 2023-01-02 04:26:40.637+00
(1 row)

Timestamps can be converted to v7 UUIDs:

SELECT uuid_timestamptz_to_v7('2023-01-02 04:26:40.637+00');
        uuid_timestamptz_to_v7
--------------------------------------
 018570bb-4a7d-7630-a5c4-89b795024c5d
(1 row)

-- for date range queries set the second argument to true to zero the random bits
SELECT uuid_timestamptz_to_v7('2023-01-02 04:26:40.637+00', true);
        uuid_timestamptz_to_v7
--------------------------------------
 018570bb-4a7d-7000-8000-000000000000
(1 row)

uuid_generate_v7() is nearly as fast as the native gen_random_uuid() function. See the benchmarks for more details.

Background

Version 7 UUIDs have a few advantages. They include a 48-bit Unix timestamp with millisecond accuracy and will overflow far in the future (10899 AD). They also include 74 random bits which means billions can be created every second without collisions. Because of their structure they are globally sortable and can be created in parallel in a distributed system.

Quickstart

These instructions are for x86_64 Linux. On other architectures follow the build instructions instead.

1. Download the latest .tar.gz release and extract it to a temporary directory
2. Copy pg_uuidv7.so for your Postgres version into the Postgres module directory
3. Copy pg_uuidv7--1.5.sql and pg_uuidv7.control into the Postgres extension directory
4. Enable the extension in the database using CREATE EXTENSION pg_uuidv7;

# example shell script to install pg_uuidv7
cd "$(mktemp -d)"
curl -LO "https://github.com/fboulnois/pg_uuidv7/releases/download/v1.5.0/{pg_uuidv7.tar.gz,SHA256SUMS}"
tar xf pg_uuidv7.tar.gz
sha256sum -c SHA256SUMS
PG_MAJOR=$(pg_config --version | sed 's/^.* \([0-9]\{1,\}\).*$/\1/')
cp "$PG_MAJOR/pg_uuidv7.so" "$(pg_config --pkglibdir)"
cp pg_uuidv7--1.5.sql pg_uuidv7.control "$(pg_config --sharedir)/extension"
psql -c "CREATE EXTENSION pg_uuidv7;"

Build

Build locally

pg_uuidv7 only requires the libpq headers and Postgres extension tools to build the code. On Debian, these headers are included in the libpq-dev and postgresql-server-dev-all packages.

To build the code run make. To install the extension locally run make install.

Build using Docker

A Dockerfile is available to build the code using the official Postgres Docker image:

docker build . --tag pg_uuidv7

A prebuilt x86_64 version of this image is on GitHub:

docker pull ghcr.io/fboulnois/pg_uuidv7:1.5.0

The prebuilt image is similar to a vanilla Postgres instance so the extension needs to be enabled manually or with an initialization script with CREATE EXTENSION pg_uuidv7;.

Test

A separate Dockerfile is available to build the extension against a specific version of Postgres and run the regression tests:

docker build . --file test/Dockerfile --tag pgxn-test
docker run --rm -it pgxn-test /bin/sh
# once in container
pg-start 16
pg-build-test

Contributing

See the CONTRIBUTING.md file for more details. In short, follow the style guidelines, agree to the Developer Certificate of Origin, and submit a PR.