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

On Sat, 2026-02-21 at 12:56 +0100, Álvaro Herrera 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.
>
> Thanks for this! I have pushed it now to 18 and master (right before
> the embargo for next week's release -- not really apologizing about
> that, since this is clearly something that's going to bite users as they
> move up to 18).

Thank you, and thanks for the code improvements.

> 1. this will cause an ABI break report for AddRelationNotNullConstraints
> in branch 18. I considered the idea of adding a shim function
> preserving the original API, but I think this is not a function likely
> to be used by third-party code. So I'll address this by adding an entry
> to .abi-compliance-history instead.

I decided not to worry about changing the signature of that global function,
because it is only used in a single place and - like you - I deem it unlikely
to be useful elsewhere.

Yours,
Laurenz Albe