Feedback-ID: ia2694551:Fastmail
Date: Tue, 5 Sep 2023 17:29:56 +0200
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: cataloguing NOT NULL constraints
Message-ID: <202309051529.cbo3eo44kdjh@alvherre.pgsql>
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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)