Re: Questionabl description in datatype.sgml

> On Sat, Jun 18, 2016 at 11:58:58AM -0400, Tom Lane wrote:
>> Tatsuo Ishii <ishii@postgresql.org> writes:
>> > In "8.13.2. Encoding Handling"
>> >    <para>
>> >     When using binary mode to pass query parameters to the server
>> >     and query results back to the client, no character set conversion
>> >     is performed, so the situation is different.  In this case, an
>> >     encoding declaration in the XML data will be observed, and if it
>> >     is absent, the data will be assumed to be in UTF-8 (as required by
>> >     the XML standard; note that PostgreSQL does not support UTF-16).
>> >     On output, data will have an encoding declaration
>> >     specifying the client encoding, unless the client encoding is
>> >     UTF-8, in which case it will be omitted.
>> >    </para>
>> 
>> > In the first sentence shouldn't "no character set conversion" be "no
>> > encoding conversion"? PostgreSQL is doing client/server encoding
>> > conversion, rather than character set conversion.
>> 
>> I think the text is treating "character set conversion" as meaning
>> the same thing as "encoding conversion"; certainly I've never seen
>> any place in our docs that draws a distinction between those terms.
>> If you think there is a difference, maybe we need to define those
>> terms somewhere.
> 
> Uh, I think Unicode is a character set, and UTF8 is an encoding.  I
> think Tatsuo is right here.

Yes, a character set is different from an encoding. I though it's a
common understanding among people.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp