BLOCKED: PG19 GA follow-up steps to complete PostgreSQL 19 support

[ihalatci]

Status: BLOCKED — do not start until both external gates below are open.

This is the final phase of PostgreSQL 19 support. Phases 1 and 2 are already merged (#383, #386); everything left is gated on PostgreSQL 19 going GA and Citus publishing PG19 packages.

Blocking gates

Both must be true before any step below is executed:

• PostgreSQL 19 GA published on Docker Hub. As of 2026-09-02 library/postgres has only 19beta1, 19beta2, 19beta3 — no GA tag.
• postgresql-19-citus-<ver> published on repos.citusdata.com. As of 2026-09-02 no postgresql-19-citus package exists at any version (PG19 currently has only hll and topn).

⚠️ Hard ordering constraint — read before dispatching update_version.yml

update_docker.py sets latest_postgres_version = postgres_19_version, so the latest and alpine images are generated from whatever postgres_19_version holds in pkgvars.

pkgvars currently reads postgres_19_version=19beta3.

If update_version.yml is dispatched for the Citus 15 release while pkgvars still says 19beta3, citus:latest and citus:alpine will be pinned to a PostgreSQL 19 beta. Step 1 must land before any release dispatch.

Note this is not triggered by merging to master — update_version.yml is workflow_dispatch only, and the publish workflows only build the Dockerfiles as they already exist in the repo.

Steps, in order

• 1. Bump pkgvars — postgres_19_version=19beta3 → the PG19 GA version. Must precede step 5.
• 2. Add postgres_19 to the build matrices in publish_docker_images_on_push.yml, publish_docker_images_cron.yml and publish_docker_images_on_tag.yml.
• 3. Update README.md (line 11) for the new supported-version set.
• 4. Confirm postgres-19/Dockerfile is on the current Citus version. It is currently ARG VERSION=14.1.0 / postgresql-$PG_MAJOR-citus-14.1; regeneration will move it to the release version, so this should be a no-op once step 5 runs.
• 5. Dispatch update_version.yml for the Citus 15 release. This regenerates Dockerfile, alpine/Dockerfile, postgres-17/18/19/Dockerfile and the changelog from the templates in citusdata/tools.

Verified side effects of step 5

Running the v0.8.39 generator against current master produces exactly these changes, which are expected and correct:

• Dockerfile / alpine/Dockerfile — rebased onto postgres_19_version (hence step 1).
• Dockerfile — postgresql-$PG_MAJOR-hll 2.19 → 2.21 and topn 2.7.0 → 2.7.1. This is pre-existing drift: latest currently ships older hll/topn than pg17/pg18. It self-corrects here, so no separate fix is needed.
• postgres-19/Dockerfile — Citus 14.1.0 → release version (step 4).
• postgres-17/Dockerfile — trailing-newline-only change, cosmetic.

Also self-corrects at this point

publish_docker_images_on_manual.yml passes no --image_type, which is an intentional "build all regular images" mode. Its main trigger currently fails because postgres_19 cannot build. Once the gates above are open it works again with no change. It is workflow_dispatch-only, so impact until then is limited.

Context

• Phase 1 — Add PostgreSQL 19 image and pkgvars entry #383, image content (postgres-18/, postgres-19/, pkgvars entries)
• Phase 2 — Switch image matrices to PostgreSQL 17/18 and adopt tools v0.8.39 #386, matrices moved to PG17/18, PG16 retired, tools pinned to v0.8.39
• Tools support landed in Add PostgreSQL 19 support, drop PostgreSQL 16 tools#423, released as v0.8.39