RE: ISO vs Unicode UTF-8 (was RE: UTF-8 signature in web and email)

From: Carl W. Brown (cbrown@xnetinc.com)
Date: Wed May 30 2001 - 17:12:07 EDT


Simon,

Thanks for the information. I am very glad that Oracle will be supporting
these characters sets properly. I look forward to using 9i. Since Oracle
will transform the Unicode from one encoding to another at the API layer, I
don't see why users can not retrieve the data in a single format. If they
retrieve it as UTF-8 that it will have the natural Unicode sorting order.
If they retrieve it as UTF-16 then they should processing as all other
UTF-16 applications and convert to UTF-32 at least on a character by
character basis for compares. Implementing special UTF-8 and UTF-32 system
that sort like UTF-16 is folly.

Carl
  -----Original Message-----
  From: unicode-bounce@unicode.org [mailto:unicode-bounce@unicode.org]On
Behalf Of Simon Law
  Sent: Wednesday, May 30, 2001 11:02 AM
  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

  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]
    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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