Add PostgreSQL 19 support to Citus

[ihalatci]

Umbrella issue for PostgreSQL 19 support and compatibility in Citus.

Goal

Support PostgreSQL 19 alongside PG17 and PG18 with clean builds, runtime correctness, regression parity, upgrade coverage, and working CI/packaging.

All support work lands on pg19-support. The branch merges to main only after the supported compatibility matrix is green.

Scope boundary

This issue tracks only:

• build and source compatibility;
• runtime correctness and crash/data-loss prevention;
• regression/expected-output compatibility;
• upgrade and downgrade paths;
• CI images, packaging, and test infrastructure required to validate PG19.

PG19 feature adoption and feature-integration work is out of scope here and is being moved to a separate umbrella. Feature issues are not sub-issues of #8597.

Beta 1 — complete

• PG19: build foundation (source-level compat, scaffold ruleutils_19.c, CI image bump) #8601 — build foundation and source compatibility
• PG19: port ruleutils into Citus as ruleutils_19.c #8602 — PG19 ruleutils port
• PG19: enable PG19beta1 test matrices in CI #8616 — PG19 CI matrices and upgrade coverage
• PG19: fix runtime bugs hit outside the regression suite #8617 — runtime fixes outside regression tests
• columnar: serialize CREATE INDEX on columnar tables for PG19 #8618 — serialize columnar CREATE INDEX
• columnar: re-implement parallel/index-only-scan suppression on PG19 #8619 — restore columnar scan suppression hooks
• PG19: migrate get_relation_info_hook to build_simple_rel_hook #8622 — migrate planner hook handling
• normalize.sed: add PG19 cosmetic-difference rules #8660 — PG19 output normalization
• Thread real LWLock tranche names through on PG19 #8623 — PG19 LWLock tranche names
• Dispatch and discriminate REPACK/CLUSTER (T_RepackStmt) on PG19 (#8613) #8624 — REPACK/CLUSTER dispatch compatibility

Beta 2 — complete

Merged compatibility work includes:

• pg19 - Stabilize clock and pg17 regression tests #8674, PG19: make partition foreign key checks deterministic #8675, Stabilize PG19 ORDER BY pushdown regression plan #8680, pg19 - Restore tdigest aggregate test plan intent #8681 — regression stabilization
• PG19: handle property graph dependency object classes #8733, PG19: stabilize columnar regression outputs #8734, PG19: fix follower cluster status replies #8738, PG19: stabilize remaining planner and shard-size outputs #8739 — property-graph, columnar, follower, and planner compatibility
• Fix PG19 CDC catalog access #8740 — CDC catalog access during logical decoding
• PG19: fix backend crash on ALTER PUBLICATION ... SET ALL TABLES EXCEPT and restore EXCEPT membership across Citus conversions #8741, Fix partition publication reconstruction #8743 — publication exclusions and partition-root reconstruction
• Fix REASSIGN OWNED with keyword target roles #8746, Normalize PG19 unnamed insert-select subquery #8748 — REASSIGN OWNED crash and unnamed-subquery normalization
• main merged into pg19-support; canonical upgrade graph from Add 13.x/14.x upgrade paths for citus_internal.distribute_object to main #8686 included
• Combined PG17/18/19 Build & Test passed after one known unrelated flake rerun: https://github.com/citusdata/citus/actions/runs/31370969880

Beta 3 — current status

Images and branch update — complete

• the-process image workflow succeeded: https://github.com/citusdata/the-process/actions/runs/31887872700
• Published image suffix: -dev-c4dad8f
• PG19 pin updated to 19beta3; upgrade image tail updated to 19beta3
• PG19 test clusters allow the proven output plugins:
  • CDC: pgoutput, wal2json, citus
  • regression shard-split coverage: pgoutput, citus
• Removed the Beta3-reverted Query.groupByAll access from the copied PG19 ruleutils
• Ported PostgreSQL security fix a3832a757101 / CVE-2026-15741 for safe EXTRACT field deparsing
• Current Beta3 compatibility/security tip: 866ab1b8951fe44f34513c1ee68ad1c9a08333d2

Beta 3 validation

Build & Test baseline:
https://github.com/citusdata/citus/actions/runs/31892579383

Integration PR run with the same head:
https://github.com/citusdata/citus/actions/runs/31892362655

The remaining functional failures are caused by PostgreSQL Beta3 psql commit d6ab88d374ab, which now drains inline COPY FROM STDIN input through the next \. after an early COPY failure. Existing Citus tests assumed the earlier psql behavior.

Open Beta 3 support blockers

Issue	PR / implementation	Current status	Remaining action
#8780	#8784	PG19-only client gate corrected; Beta3/Beta2 check-failure 38/38 and PG16–18 compatibility green	Let PR CI complete, review, merge
#8781	#8785	PG19-only alternatives; Beta3/Beta2 schedules green; packaged-client suffix correction and final matrix in progress	Finish correction validation, update PR head, review, merge
#8774	packaging#1203; the-process#222	Beta3 test images published; packaging images remain missing/incomplete	Review/merge #1203, publish images, rerun four packaging cells or explicitly exclude them
Integration	#8753	Open pg19-support → main PR; current red tests are #8780/#8781 Beta3 COPY compatibility plus packaging	Land #8780/#8781, refresh CI, resolve/separate packaging, merge

These are compatibility/test-infrastructure items, not feature adoption.

Integration gate

• Merge PG19 Beta3: adapt COPY failure tests to psql input draining #8784 and PG19 Beta3: adapt COPY regressions to psql input draining #8785
• Resolve or explicitly separate packaging blocker PG19: packaging images still missing or lack PG19 (follow-up to #8731) #8774
• Rerun Build & Test on the final pg19-support tip
• Confirm PG17, PG18, and PG19 Beta3 compatibility matrices are green
• Refresh PR Pg19 support #8753 and merge pg19-support to main

Verification rule

New failures are added here only after source inspection or runtime reproduction establishes a concrete PG19 compatibility, correctness, CI, upgrade, or packaging gap. Feature-adoption proposals belong in the separate feature-integration umbrella #8782.