From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Paquier <michael@paquier.xyz>
Cc: Richard Guo <guofenglinux@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: ERROR: no NOT NULL constraint found to drop
Date: Mon, 10 Apr 2023 09:46:59 -0400
Message-ID: <4031605.1681134419@sss.pgh.pa.us> (raw)
In-Reply-To: <ZDPA8BJ4YgZymdoY@paquier.xyz>
References: <CAMbWs48astPDb3K+L89wb8Yju0jM_Czm8svmU=Uzd+WM61Cr6Q@mail.gmail.com>
<ZDPA8BJ4YgZymdoY@paquier.xyz>
Michael Paquier <michael@paquier.xyz> writes:
> On Mon, Apr 10, 2023 at 03:16:06PM +0800, Richard Guo wrote:
>> I run into error $subject with the query below:
>> # create table t1 (c int primary key null unique);
>> CREATE TABLE
>> # create table t2 (like t1);
>> CREATE TABLE
>> # alter table t2 alter c drop not null;
>> ERROR: no NOT NULL constraint found to drop
> Thanks for the report. This is not the only issue that has been
> pointed out with this patch, so it is going to be reverted if you look
> around here:
It's still good to know about it for next time. The issue I guess is
that LIKE with no options propagates column attnotnull bits, but not
constraints, so we now have an inconsistency: t2.c has attnotnull set
but there is nothing in pg_constraint to justify it. It seems to me
we're going to have to think about what we want to happen in this
case. In a green field we'd probably not propagate NOT NULL unless
told to copy constraints ... but is it okay to break functional
compatibility with the old behavior?
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-bugs@postgresql.org
Cc: tgl@sss.pgh.pa.us, michael@paquier.xyz, guofenglinux@gmail.com, alvherre@alvh.no-ip.org, pgsql-bugs@lists.postgresql.org
Subject: Re: ERROR: no NOT NULL constraint found to drop
In-Reply-To: <4031605.1681134419@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox