Re: NOT ENFORCED constraint feature

amul sul <sulamul@gmail.com>

From: Amul Sul <sulamul@gmail.com>

To: Álvaro Herrera <alvherre@alvh.no-ip.org>

Cc: Peter Eisentraut <peter@eisentraut.org>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, jian he <jian.universality@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Joel Jacobson <joel@compiler.org>, Alexandra Wang <alexandra.wang.oss@gmail.com>, Suraj Kharage <suraj.kharage@enterprisedb.com>

Date: 2025-03-27T04:48:46Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add support for NOT ENFORCED in foreign key constraints
- eec0040c4bcd 18.0 landed
Expand test a bit
- 5d5f415816a6 18.0 landed
refactor: Pass relation OID instead of Relation to createForeignKeyCheckTriggers()
- ef7a5af77d44 18.0 landed
refactor: Split ATExecAlterConstraintInternal()
- 639238b978fe 18.0 landed
refactor: Move some code that updates pg_constraint to a separate function
- a3280e2a494f 18.0 landed
Move RemoveInheritedConstraint() call slightly earlier
- dabccf45139a 18.0 landed
refactor: Split tryAttachPartitionForeignKey()
- 1d26c2d2c4b8 18.0 landed
refactor: re-add ATExecAlterChildConstr()
- 64224a834ce4 18.0 landed
Add ATAlterConstraint struct for ALTER .. CONSTRAINT
- 80d7f990496b 18.0 landed
refactor: split ATExecAlterConstrRecurse()
- 7a947ed25b54 18.0 landed
Add support for NOT ENFORCED in CHECK constraints
- ca87c415e2fc 18.0 landed

On Wed, Mar 26, 2025 at 12:29 PM Álvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>
> On 2025-Mar-26, Amul Sul wrote:
>
> > The reason for the change is to revert to the behavior before commit
> > #80d7f990496b1c, where recursion occurred regardless of the
> > changed flags. This is also described in the header comment for
> > ATExecAlterConstrDeferrability() (earlier it was for
> > ATExecAlterConstraintInternal):
> >
> >  * Note that we must recurse even when the values are correct, in case
> >  * indirect descendants have had their constraints altered locally.
> >  * (This could be avoided if we forbade altering constraints in partitions
> >  * but existing releases don't do that.)
>
> Umm, why?  Surely we should not allow a partition tree to become
> inconsistent.
>

I just checked, and we are not allowed to alter a constraint on the
child table alone, nor can we merge it when attaching to the parent
constraint if the deferrability is different. Therefore, I think we
should remove this comment as it seems outdated now.

Regards,
Amul