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: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers@lists.postgresql.org
Date: 2023-07-24T17:17:33Z
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

Hello,

While discussing the matter of multiple constraints with Vik Fearing, I
noticed that we were throwing an unnecessary error if you used

CREATE TABLE foo (a int NOT NULL NOT NULL);

That would die with "redundant NOT NULL declarations", but current
master doesn't do that; and we don't do it for UNIQUE UNIQUE either.
So I modified the patch to make it ignore the dupe and create a single
constraint.  This (and rebasing to current master) are the only changes
in v15.

I have not changed the psql presentation, but I'll do as soon as we have
rough consensus on what to do.  To reiterate, the options are:

1. Don't show the constraint names.  This is what the current patch does

2. Show the constraint name in \d+ in the "nullable" column.
   I did this early on, to much booing.

3. Show the constraint name in \d++ (a new command) tabular output

4. Show the constraint name in the footer of \d+
   I also did this at some point; there are some +1s and some -1s.

5. Show the constraint name in the footer of \d++


Many thanks, Dean, for the discussion so far.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
Bob [Floyd] used to say that he was planning to get a Ph.D. by the "green
stamp method," namely by saving envelopes addressed to him as 'Dr. Floyd'.
After collecting 500 such letters, he mused, a university somewhere in
Arizona would probably grant him a degree.              (Don Knuth)