Re: cataloguing NOT NULL constraints

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

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-09-05T15:29:56Z
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 2023-Sep-05, Peter Eisentraut wrote:

> The following information schema views are affected by the not-null
> constraint catalog entries:
> 
> 1. CHECK_CONSTRAINTS
> 2. CONSTRAINT_COLUMN_USAGE
> 3. DOMAIN_CONSTRAINTS
> 4. TABLE_CONSTRAINTS
> 
> Note that 1 and 3 also contain domain constraints.  So as long as the domain
> not-null constraints are not similarly catalogued, we can't delete the
> separate not-null union branch.  (3 never had one, so arguably a bit buggy.)
> 
> I think we can fix up 4 by just deleting the not-null union branch.
> 
> For 2, the simple fix is also easy, but there are some other options, as you
> discuss above.
> 
> How do you want to proceed?

I posted as a patch in a separate thread[1].  Let me fix up the
definitions for views 1 and 3 for domains per your comments, and I'll
post in that thread again.

[1] https://postgr.es/m/202309041710.psytrxlsiqex@alvherre.pgsql

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"Ninguna manada de bestias tiene una voz tan horrible como la humana" (Orual)