Re: cataloguing NOT NULL constraints

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-09-20T10:51:09Z
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 →
  1. Revert structural changes to not-null constraints

  2. Fix inconsistencies in error messages

  3. Disallow direct change of NO INHERIT of not-null constraints

  4. Disallow NO INHERIT not-null constraints on partitioned tables

  5. Better handle indirect constraint drops

  6. Don't try to assign smart names to constraints

  7. Fix restore of not-null constraints with inheritance

  8. ATTACH PARTITION: Don't match a PK with a UNIQUE constraint

  9. Fix propagating attnotnull in multiple inheritance

  10. Check stack depth in new recursive functions

  11. Move privilege check to the right place

  12. Update information_schema definition for not-null constraints

  13. Fix not-null constraint test

  14. Disallow changing NO INHERIT status of a not-null constraint

  15. Catalog not-null constraints

  16. parallel_schedule: add comment on event_trigger test dependency

  17. Revert "Catalog NOT NULL constraints" and fallout

  18. Adjust contrib/sepgsql regression test expected outputs.

  19. Fix table name clash in recently introduced test

  20. Catalog NOT NULL constraints

  21. Change the rules for inherited CHECK constraints to be essentially the same

On 2022-Sep-19, Robert Haas wrote:

> On Wed, Aug 17, 2022 at 2:12 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

> > 55489 16devel 1776237=# \d tab
> >                     Tabla «public.tab»
> >  Columna │  Tipo   │ Ordenamiento │ Nulable  │ Por omisión
> > ─────────┼─────────┼──────────────┼──────────┼─────────────
> >  a       │ integer │              │ not null │
> > Restricciones CHECK:
> >     "tab_a_not_null" CHECK (a IS NOT NULL)
> 
> In a table with many columns, most of which are NOT NULL, this is
> going to produce a ton of clutter. I don't like that.
> 
> I'm not sure what a good alternative would be, though.

Perhaps that can be solved by displaying the constraint name in the
table:

 55489 16devel 1776237=# \d tab
                     Tabla «public.tab»
  Columna │  Tipo   │ Ordenamiento │     Nulable    │ Por omisión
 ─────────┼─────────┼──────────────┼────────────────┼─────────────
  a       │ integer │              │ tab_a_not_null │ 

(Perhaps we can change the column title also, not sure.)

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"The Gord often wonders why people threaten never to come back after they've
been told never to return" (www.actsofgord.com)