Simon Law wrote:
In Oracle9i our next Database Release shipping this summer, we have
introduced support for two new Unicode character sets. One is 'AL16UTF16'
which supports the UTF-16 encoding and the other is 'AL32UTF8' which is the
UTF-8 fully compliant character set. Both of these conform to the Unicode
standard, and surrogate characters are stored strictly in 4 bytes. For more
information on Unicode support in Oracle9i , please check out the whitepaper
"The power of Globalization Technology" on
http://otn.oracle.com/products/oracle9i/content.html
<http://otn.oracle.com/products/oracle9i/content.html>
And here is what I found in the mentioned paper "The power of Globalization
Technology"
UTF-8 Encoding
......
One Unicode character can be 1-byte, 2-bytes, or 3-bytes in this encoding.
Generally characters from the European scripts are represented in either 1
or 2
bytes, while characters from most Asian scripts are represented in 3 bytes.
UTF-16 Encoding
This is the 16-bit encoding of Unicode. It is a 2 byte fixed-width encoding
in which
the character codes 0x0000 through 0x007F have the same meaning as ASCII.
One
Unicode character is 2-bytes in this encoding. Characters from all scripts
are
represented in 2 bytes.
</quote>
Comments?
-----Original Message-----
From: Simon Law [mailto:simon.law@oracle.com]
Sent: Wednesday, May 30, 2001 8:02 PM
To: unicode@unicode.org
Subject: Re: ISO vs Unicode UTF-8 (was RE: UTF-8 signature in web and email)
Hi Folks,
Over the last few days, this email thread has generated many interesting
discussions on the proposal of UTF-8s. At the same time some speculations
have been generated on why Oracle is asking for this encoding form. I hope
to clarify some of these misinformation in this email.
In Oracle9i our next Database Release shipping this summer, we have
introduced support for two new Unicode character sets. One is 'AL16UTF16'
which supports the UTF-16 encoding and the other is 'AL32UTF8' which is the
UTF-8 fully compliant character set. Both of these conform to the Unicode
standard, and surrogate characters are stored strictly in 4 bytes. For more
information on Unicode support in Oracle9i , please check out the whitepaper
"The power of Globalization Technology" on
http://otn.oracle.com/products/oracle9i/content.html
<http://otn.oracle.com/products/oracle9i/content.html>
The requests for UTF-8s came from many of our Packaged Applications
customers (such as Peoplesoft , SAP etc.), the ordering of the binary sort
is an important requirement for these Oracle customers. We are supporting
them and we hope to turn this into a TR such that UTF-8s can be referenced
by other vendors when they need to have compatible binary order for UTF-16
and UTF-8 across different platforms.
The speculation that we are pushing for UTF-8s because we are trying to
minimize our code change for supporting surrogates, or because of our
unique database design are totally false. Oracle has a fully
internationalized extensible architecture and have introduced surrogate
support in Oracle9i. In fact we are probably the first database vendor to
support both the UTF-16 and UTF-8 encoding forms, we will continue to
support them and conform to future enhancements to the Unicode Standard.
Regards
Simon
"Carl W. Brown" wrote:
Ken,
I suspect that Oracle is specifically pushing for this standard because of
its unique data base design. In a sense Oracle almost picks it self up by
its own bootstraps. It has always tried to minimize actual code. Therefore
it was a natural choice to implement Unicode with UTF-8 because it is easy
to reuse the multibyte support with minor changes to handle a different
character length algorithm. This has been one of the reasons that Oracle
has been successful. Its tinker toy like design has enabled them to quickly
adapt and add new features. Now however, they should take the time do "do
it right". Its UTF-8 storage creates problems for database designers
because they can not predict field sizes. This is a problem with MBCS code
pages but UTF-8s will make it worse. There will be lots of wasted storage
when characters can vary in size from 1 to 6 bytes.
Most other database systems require specific code to support Unicode. As a
consequence most have implemented using UCS-2. Their migration is obviously
to use UTF-16. UTF-8s buys them nothing but headaches.
Carl
-----Original Message-----
From: Kenneth Whistler [ mailto:kenw@sybase.com <mailto:kenw@sybase.com> ]
Sent: Tuesday, May 29, 2001 3:47 PM
To: cbrown@xnetinc.com
Cc: unicode@unicode.org; kenw@sybase.com
Subject: RE: ISO vs Unicode UTF-8 (was RE: UTF-8 signature in web and
email)
Carl,
> Ken,
>
> UTF-8s is essentially a way to ignore surrogate processing. It allows a
> company to encode UTF-16 with UCS-2 logic.
>
> The problem is that by not implementing surrogate support you can
introduce
> subtle errors. For example it is common to break buffers apart into
> segments. These segments may be reconcatinated but they may be processed
> individually.
You are preaching to the choir here. I didn't state that *I* was in
favor of UTF-8S -- only that we have to be careful not to assume that
UTC will obviously not support it. The proponents of UTF-8S are
vigorously and actively campaigning for their proposal. In
standardization committees, proposals that have committed, active
proponents who can aim for the long haul, often have a way of getting
adopted in one form or another, unless there are equally committed
and active opponents of the proposal. It is just the nature of
consensus politicking in these committees, whether corporate based
or national body based.
Also, I consider the stated position of "near-universal agreement
among the database vendors" to be largely a rhetorical device by
the proponents. Oracle is clearly pushing the proposal. NCR has
stated it is not in favor of the proposal. The other big enterprise
database vendors are hedging their positions somewhat -- in
particular, the standards people in those companies may not be
entirely in agreement with some of their database engine developers, for
example. And the small database vendors are either not playing
in this space or are part of desktop systems that will just follow
the behavior of the platforms.
--Ken
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