Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps
 (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <pgsql-bugs-owner+archive@lists.postgresql.org>)
	id 1p5qC8-0006vD-84
	for pgsql-bugs@arkaria.postgresql.org; Thu, 15 Dec 2022 15:30:48 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.92)
	(envelope-from <pgsql-bugs-owner+archive@lists.postgresql.org>)
	id 1p5qC5-0002iR-9q
	for pgsql-bugs@arkaria.postgresql.org; Thu, 15 Dec 2022 15:30:45 +0000
Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29])
	by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <vik@postgresfriends.org>)
	id 1p5qC5-0002gy-1g
	for pgsql-bugs@lists.postgresql.org; Thu, 15 Dec 2022 15:30:45 +0000
Received: from relay1-d.mail.gandi.net ([217.70.183.193])
	by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.92)
	(envelope-from <vik@postgresfriends.org>)
	id 1p5qC2-0006to-TM
	for pgsql-bugs@lists.postgresql.org; Thu, 15 Dec 2022 15:30:44 +0000
Received: (Authenticated sender: vik@postgresfriends.org)
	by mail.gandi.net (Postfix) with ESMTPSA id 81AAB24000D;
	Thu, 15 Dec 2022 15:30:37 +0000 (UTC)
Message-ID: <9344998b-e9aa-fdd8-9a7e-3f17811599fa@postgresfriends.org>
Date: Thu, 15 Dec 2022 16:30:36 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.4.2
Subject: Re: BUG #17720: pg_dump creates a dump with primary key that cannot
 be restored, when specifying 'using index ...'
Content-Language: en-US
To: Daniel Gustafsson <daniel@yesql.se>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
 "David G. Johnston" <david.g.johnston@gmail.com>,
 "zedaardv@drizzle.com" <zedaardv@drizzle.com>,
 "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
References: <17720-dab8ee0fa85d316d@postgresql.org>
 <CAKFQuwam=1NoSNH=EJRUnuuD8JE_jM8tq22-SYqO1nxzoXFwzg@mail.gmail.com>
 <9C039DE3-EFBD-4D65-B4CF-90D8148B7B4C@yesql.se>
 <2684951.1671032222@sss.pgh.pa.us>
 <20CD10FD-A9C2-47D0-9A75-B86532BC058E@yesql.se>
 <3039077.1671060472@sss.pgh.pa.us>
 <9566C00C-6A3B-4CC7-8C7C-1A0477A5C752@yesql.se>
From: Vik Fearing <vik@postgresfriends.org>
In-Reply-To: <9566C00C-6A3B-4CC7-8C7C-1A0477A5C752@yesql.se>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
List-Id: <pgsql-bugs.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-bugs@lists.postgresql.org>
List-Owner: <mailto:pgsql-bugs-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-bugs>
Archived-At: 
 <https://www.postgresql.org/message-id/9344998b-e9aa-fdd8-9a7e-3f17811599fa%40postgresfriends.org>
Precedence: bulk

On 12/15/22 14:18, Daniel Gustafsson wrote:
>> On 15 Dec 2022, at 00:27, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>
>> Daniel Gustafsson <daniel@yesql.se> writes:
>>> The attached prohibits the use of NULLS NOT DISTINCT for backing primary key
>>> constraints but allow them for unique constraints.  Is this along the lines of
>>> what you had in mind?
>>
>> Needs more than zero comments in the code, and why bother testing
>> is_alter_table in index_check_primary_key?  We're disallowing
>> this case across-the-board, no matter how you get to it.
> 
> That was an, admittedly poor, attempt at self-documenting code.  Removed and
> comments added in the attached.

[reviewing patch...]

If the point in adding a primary key USING INDEX is to avoid building an 
index, then this restriction defeats that purpose.  We have no ALTER 
INDEX command to switch or drop the <unique null treatment>.

Since the primary key can't have any nulls anyway, I think we should 
just flip this, perhaps with a NOTICE like the rename does.
-- 
Vik Fearing