Received: from malur.postgresql.org ([217.196.149.56])
 by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from
 <pgsql-hackers-owner+M234315=pgsql-hackers-arkari@postgresql.org>)
 id 1VORJr-0004dv-83
 for pgsql-hackers@arkaria.postgresql.org; Tue, 24 Sep 2013 12:02:19 +0000
Received: from localhost ([127.0.0.1] helo=postgresql.org)
 by malur.postgresql.org with smtp (Exim 4.80) (envelope-from
 <pgsql-hackers-owner+M234315=pgsql-hackers-arkari@postgresql.org>)
 id 1VORJq-0002CY-NU
 for pgsql-hackers@arkaria.postgresql.org; Tue, 24 Sep 2013 12:02:18 +0000
Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29])
 by malur.postgresql.org with esmtp (Exim 4.80)
 (envelope-from <maumau307@gmail.com>) id 1VORJo-0002CP-Pp
 for pgsql-hackers@postgresql.org; Tue, 24 Sep 2013 12:02:17 +0000
Received: from mail-pa0-x22e.google.com ([2607:f8b0:400e:c03::22e])
 by magus.postgresql.org with esmtp (Exim 4.80)
 (envelope-from <maumau307@gmail.com>)
 id 1VORJl-0006wd-6j; Tue, 24 Sep 2013 12:02:15 +0000
Received: by mail-pa0-f46.google.com with SMTP id fa1so4860481pad.19
 for <multiple recipients>; Tue, 24 Sep 2013 05:02:10 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=message-id:from:to:cc:references:in-reply-to:subject:date
 :mime-version:content-type:content-transfer-encoding;
 bh=hgN47eRPpTgnYJZL7XU9KHPyiOiRFoxxS2zGpX15wcg=;
 b=PAWr+WQahenkslaJ4a7lE+rGqtixvIuBSEtbBZu5QmpIfTh0YL9g1SN3HkA5zvu+dw
 bn1R4+qomv5++BAxK4Hi75VcupcgnoPOuVEdtceNY1qjROXQYFxRc2Hj5HL3EhL7GLuQ
 bqqbDhmvX7ZwTkMvC13isJC/WawwlTtS3CzyJ3fEnodPWTbtg/cmOLK6GD+FBRbvYpJ6
 eNKU2bOcH/VmZvG5PyiSDg4Zxv6Lk42PJhrvaGLZPOd3PdfOD+NaGXGFyR/vehPx+8ZJ
 N3ZYzCKFZEl1Fss70i6Z/Hl3zjb6vC392Qj0Wg8dL9eP1zblqjGiQ9n1oymSdEj21Mtw
 ERBw==
X-Received: by 10.66.248.161 with SMTP id yn1mr28230864pac.0.1380024130606;
 Tue, 24 Sep 2013 05:02:10 -0700 (PDT)
Received: from maumau (p6019-ipbfp211sizuokaden.shizuoka.ocn.ne.jp.
 [114.170.213.19])
 by mx.google.com with ESMTPSA id ia5sm40432662pbc.42.1969.12.31.16.00.00
 (version=TLSv1 cipher=RC4-SHA bits=128/128);
 Tue, 24 Sep 2013 05:02:09 -0700 (PDT)
Message-ID: <7DCFAE8265254605840917B35EEF09F1@maumau>
From: "MauMau" <maumau307@gmail.com>
To: "Peter Eisentraut" <peter_e@gmx.net>
Cc: <robertmhaas@gmail.com>, "Tatsuo Ishii" <ishii@postgresql.org>,
 <tgl@sss.pgh.pa.us>, <maksymb@fast.au.fujitsu.com>,
 <hlinnakangas@vmware.com>, <pgsql-hackers@postgresql.org>
References: 
 <CA+TgmobWv_96dSfSHv2ZJWSXAD=QTiBEKw-LT359sGArYe+AXQ@mail.gmail.com><20130920.085853.1628917054830864151.t-ishii@sraoss.co.jp><CA+TgmoZEy=pt2B5D+nuPAib7KvhNoBgRGYRWnkS4pyrqfcdYHQ@mail.gmail.com>
 <20130922.072952.1977066018971837040.t-ishii@sraoss.co.jp>
 <D0A2FE73E8354EDCBEE56EC79268CA4E@maumau> <5240B212.8040307@gmx.net>
In-Reply-To: <5240B212.8040307@gmx.net>
Subject: Re: UTF8 national character data type support WIP patch and list of
 open issues.
Date: Tue, 24 Sep 2013 21:04:14 +0900
MIME-Version: 1.0
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
 reply-type=original
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Windows Mail 6.0.6002.18197
X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463
X-Pg-Spam-Score: -1.3 (-)
List-Archive: <http://archives.postgresql.org/pgsql-hackers>
List-Help: <mailto:majordomo@postgresql.org?body=help>
List-ID: <pgsql-hackers.postgresql.org>
List-Owner: <mailto:pgsql-hackers-owner@postgresql.org>
List-Post: <mailto:pgsql-hackers@postgresql.org>
List-Subscribe: <mailto:majordomo@postgresql.org?body=sub%20pgsql-hackers>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-hackers>
X-Mailing-List: pgsql-hackers
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

From: "Peter Eisentraut" <peter_e@gmx.net>
> That assumes that the conversion client encoding -> server encoding ->
> NCHAR encoding is not lossy.

Yes, so Tatsuo san suggested to restrict server encoding <-> NCHAR encoding 
combination to those with lossless conversion.


> I thought one main point of this exercise
> was the avoid these conversions and be able to go straight from client
> encoding into NCHAR.

It's slightly different.  Please see the following excerpt:

http://www.postgresql.org/message-id/B1A7485194DE4FDAB8FA781AFB570079@maumau

"4. I guess some users really want to continue to use ShiftJIS or EUC_JP for
database encoding, and use NCHAR for a limited set of columns to store
international text in Unicode:
- to avoid code conversion between the server and the client for performance
- because ShiftJIS and EUC_JP require less amount of storage (2 bytes for
most Kanji) than UTF-8 (3 bytes)
This use case is described in chapter 6 of "Oracle Database Globalization
Support Guide"."



Regards
MauMau



-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers