Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps  (TLS1.3) tls
 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
	(Exim 4.94.2)
	(envelope-from <pgsql-bugs-owner+archive@lists.postgresql.org>)
	id 1sZ5v5-00GNhA-SU
	for pgsql-bugs@arkaria.postgresql.org; Wed, 31 Jul 2024 09:46:56 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.94.2)
	(envelope-from <pgsql-bugs-owner+archive@lists.postgresql.org>)
	id 1sZ5v4-004Qxc-9k
	for pgsql-bugs@arkaria.postgresql.org; Wed, 31 Jul 2024 09:46:54 +0000
Received: from makus.postgresql.org ([2001:4800:3e1:1::229])
	by malur.postgresql.org with esmtps  (TLS1.3) tls
 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
	(Exim 4.94.2)
	(envelope-from <depesz@depesz.com>)
	id 1sZ5v3-004QvG-V3
	for pgsql-bugs@lists.postgresql.org; Wed, 31 Jul 2024 09:46:54 +0000
Received: from lana.depesz.com ([88.198.49.178] helo=depesz.com)
	by makus.postgresql.org with esmtps  (TLS1.3) tls
 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
	(Exim 4.94.2)
	(envelope-from <depesz@depesz.com>)
	id 1sZ5v1-002M4N-3s
	for pgsql-bugs@lists.postgresql.org; Wed, 31 Jul 2024 09:46:52 +0000
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=depesz.com;
	s=20170201; h=In-Reply-To:Content-Type:MIME-Version:References:Reply-To:
	Message-ID:Subject:To:Sender:From:Date:Cc:Content-Transfer-Encoding:
	Content-ID:Content-Description;
	bh=INVhXT2l5hWCAA7jdQvd2bUOqnACJ7xjx3jhLU6bH48=; b=FMn+Tl3jOL0LCnjT/l3dXk3iZj
	r0GOW8yCiStuPiqqcERqVY0MTr5KVlfGXZmHSrTfXCk914hVPZMRYKYVhLi6zsrsjQMnSa6Q3Cdjz
	Dj1RkFMFGfm4iABjp82ww0jn+8D9CYmMkpKi3IaSVYBO8Jx1kMF9RESYzf0Lo9ljQF5k=;
Received: from depesz by depesz.com with local (Exim 4.96)
	(envelope-from <depesz@depesz.com>)
	id 1sZ5ux-005yZU-01;
	Wed, 31 Jul 2024 11:46:47 +0200
Date: Wed, 31 Jul 2024 11:46:46 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: ammmkilo@163.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18560: Inconsistent Behavior of PostgreSQL 'LIKE' Operator
Message-ID: <ZqoIBlVvEsntf9Eu@depesz.com>
Reply-To: depesz@depesz.com
References: <18560-c6c21c3b8d5c3f9b@postgresql.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <18560-c6c21c3b8d5c3f9b@postgresql.org>
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/ZqoIBlVvEsntf9Eu%40depesz.com>
Precedence: bulk

On Wed, Jul 31, 2024 at 04:47:23AM +0000, PG Bug reporting form wrote:
> CREATE TABLE t0(c0 INT NOT NULL, c1 CHAR(1) UNIQUE);

I bet the thing is simply one more edge case that proves that one
shouldn't be using char(n) datatype:
https://wiki.postgresql.org/wiki/Don't_Do_This#Don.27t_use_char.28n.29

Best regards,

depesz