Horton

Re: cataloguing NOT NULL constraints

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

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2023-08-09T11:10:29Z
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-Aug-09, Peter Eisentraut wrote:

> I wonder whether the root of these problems is that we mix together primary
> key constraints and not-null constraints.  I understand that right now, with
> the proposed patch, when a table inherits from a parent table with a primary
> key constraint, we generate not-null constraints on the child, in order to
> enforce the not-nullness.  What if we did something like this instead: In
> the child table, we don't generate a not-null constraint, but instead a
> primary key constraint entry.  But we mark the primary key constraint
> somehow to say, this is just for the purpose of inheritance, don't enforce
> uniqueness, but enforce not-nullness.  Would that work?

Hmm.  One table can have many parents, and many of them can have primary
keys.  If we tried to model it the way you suggest, the child table
would need to have several primary keys.  I don't think this would work.

But I think I just need to stare at the dependency graph a little while
longer.  Maybe I just need to add some extra edges to make it work
correctly.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/