Subject: pgsql: Avoid name collision with NOT NULL constraints

From: Álvaro Herrera <[email-masked]>
Date: Sat, 21 Feb 2026 11:25:23 +0000

Avoid name collision with NOT NULL constraints

If a CREATE TABLE statement defined a constraint whose name is identical
to the name generated for a NOT NULL constraint, we'd throw an
(unnecessary) unique key violation error on
pg_constraint_conrelid_contypid_conname_index: this can easily be
avoided by choosing a different name for the NOT NULL constraint.

Fix by passing the constraint names already created by
AddRelationNewConstraints() to AddRelationNotNullConstraints(), so that
the latter can avoid name collisions with them.

Bug: #19393
Author: Laurenz Albe <[email-masked]>
Reported-by: Hüseyin Demir <[email-masked]>
Backpatch-through: 18
Discussion: https://postgr.es/m/[email-masked]

Branch
------
REL_18_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/8d9a97e0bb6d820dac553848f0d5d8cc3f3e219d

Modified Files
--------------
src/backend/catalog/heap.c                 |  8 +++++---
src/backend/commands/tablecmds.c           | 18 ++++++++++++++----
src/include/catalog/heap.h                 |  3 ++-
src/test/regress/expected/create_table.out |  6 ++++++
src/test/regress/sql/create_table.sql      |  7 +++++++
5 files changed, 34 insertions(+), 8 deletions(-)