Re: cataloguing NOT NULL constraints

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

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Michael Paquier <michael@paquier.xyz>
Cc: Alexander Lakhin <exclusion@gmail.com>, Dean Rasheed <dean.a.rasheed@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-02-05T09:50:56Z
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

Attachments

On 2024-Feb-05, Alvaro Herrera wrote:

> Hmm, let me have a look, I can probably get this one fixed today before
> embarking on a larger fix elsewhere in the same feature.

You know what -- this missing CCI has a much more visible impact, which
is that the attnotnull marker that a primary key imposes on a partition
is propagated early.  So this regression test no longer fails:

create table cnn2_parted(a int primary key) partition by list (a);
create table cnn2_part1(a int);
alter table cnn2_parted attach partition cnn2_part1 for values in (1);

Here, in the existing code the ALTER TABLE ATTACH fails with the error
message that
  ERROR:  primary key column "a" is not marked NOT NULL
but with the patch, this no longer occurs.

I'm not sure that this behavior change is desirable ... I have vague
memories of people complaining that this sort of error was not very
welcome ... but on the other hand it seems now pretty clear that if it
*is* desirable, then its implementation is no good, because a single
added CCI breaks it.

I'm leaning towards accepting the behavior change, but I'd like to
investigate a little bit more first, but what do others think?

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/