From: Tom Lane <tgl@sss.pgh.pa.us>
To: Martijn van Oosterhout <kleptog@svana.org>
cc: Tatsuo Ishii <ishii@postgresql.org>, maumau307@gmail.com,
 laurenz.albe@wien.gv.at, robertmhaas@gmail.com, peter_e@gmx.net,
 arul@fast.au.fujitsu.com, stark@mit.edu, Maksym.Boguk@au.fujitsu.com,
 hlinnakangas@vmware.com, pgsql-hackers@postgresql.org
Subject: Re: UTF8 national character data type support WIP patch and list of
 open issues.
In-reply-to: <20131113201950.GA800@svana.org>
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 <7A2BD06B10A24EA4AA5FC5D93A70A754@maumau> <30151.1384101976@sss.pgh.pa.us>
 <20131112.155752.666523035722474275.t-ishii@sraoss.co.jp>
 <20131113201950.GA800@svana.org>
Comments: In-reply-to Martijn van Oosterhout <kleptog@svana.org>
 message dated "Wed, 13 Nov 2013 21:19:50 +0100"
Date: Wed, 13 Nov 2013 15:31:38 -0500
Message-ID: <24268.1384374698@sss.pgh.pa.us>
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Sender: pgsql-hackers-owner@postgresql.org

Martijn van Oosterhout <kleptog@svana.org> writes:
> On Tue, Nov 12, 2013 at 03:57:52PM +0900, Tatsuo Ishii wrote:
>> Once we implement the universal encoding, other problem such as
>> "pg_database with multiple encoding problem" can be solved easily.

> Isn't this essentially what the MULE internal encoding is?

MULE is completely evil.  It has N different encodings for the same
character, not to mention no support code available.

>> Currently there's no such an universal encoding in the universe, I
>> think the only way is, inventing it by ourselves.

> This sounds like a terrible idea. In the future people are only going
> to want more advanced text functions, regular expressions, indexing and
> making encodings that don't exist anywhere else seems like a way to
> make a lot of work for little benefit.

Agreed.

> A better idea seems to me is to (if postgres is configured properly)
> embed the non-round-trippable characters in the custom character part
> of the unicode character set. In other words, adjust the mappings
> tables on demand and voila.