Horton

Re: BUG #19393: pg_upgrade fails with duplicate key violation when CHECK constraint named *_not_null exists

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: huseyin.d3r@gmail.com, pgsql-bugs@lists.postgresql.org
Date: 2026-02-06T07:23:33Z
Lists: pgsql-bugs, pgsql-hackers 
On Thu, Feb 5, 2026 at 10:22 PM Laurenz Albe <laurenz.albe@cybertec.at> wrote:
>
> On Thu, 2026-02-05 at 15:58 +0100, I wrote:
> > The bug is actually not in pg_upgrade, but in CREATE TABLE.  The attached patch
> > fixes the problem for me by avoiding given constraint names when generating
> > the names for NOT NULL constraints.
>
> ... and here is v2, including a regression test.

The fix LGTM. However I have one question, have you considered
validating the name selection logic for other constraint types as
well? I’m specifically thinking about AddRelationNewConstraints().
While I don't have a specific test case yet, is it possible for the
AddRelationNewConstraints to choose a name that is already in use when
adding a new column with a constraint?

-- 
Regards,
Dilip Kumar
Google

Commits

  1. Update .abi-compliance-history for AddRelationNotNullConstraints().

  2. Avoid name collision with NOT NULL constraints