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[Bug 6601] SAP uses precisionDecimal with 16 and with 8 bytes.

From: <bugzilla@wiggum.w3.org>
Date: Mon, 23 Feb 2009 14:56:01 +0000
To: www-xml-schema-comments@w3.org
Message-Id: <E1LbcDx-0002Uv-CN@wiggum.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6601





--- Comment #1 from David Ezell <David_E3@VERIFONE.com>  2009-02-23 14:56:00 ---
At 5:41 PM +0000 2009-02-20, bugzilla@farnsworth.w3.org wrote:
>http://www.w3.org/Bugs/Public/show_bug.cgi?id=6601

>         ReportedBy: Matthias.Mittelstein@sap.com

>Dear XML Schema Working Group.
>
>With reference to the new W3C XSD 1.1 I want to write you, that we at 
>SAP are using decimal floating numbers and we are interested in all 
>standards which help to make xs:precisionDecimal usable and interchangeable.
>
>We are using two formats:
>*     *DECFLOAT34*
>    This type can hold up to 34 decimal mantissa digits. The possible 
>values range from 1E-6143 through 
>9.999999999999999999999999999999999E+6144 plus the corresponding negative values and zero. Such a number occupies 16 bytes.
>
>*     *DECFLOAT16*
>    This is the smaller variant of the decimal floating-point types. It 
>allows up to 16 decimal mantissa digits and values in the range from 
>1E-383 through
>9.999999999999999E+384 plus negative values and zero. This type needs 8 bytes.

I conclude that your "bug" report is not really reporting a bug, but rather a
user endorsement for including precisionDecimal in the 1.1 specification, for
which I sincerely thank you.

For your information, in the discussion of
    http://www.w3.org/Bugs/Public/show_bug.cgi?id=3251 , the desirability of
introducing precisionDecimal was questioned, with the following decision by the
working group:

>The WG presented to QT on 27 June its decision/proposal to (1) mark 
>precisionDecimal as a "topic at risk" when the CR is released, (2) not 
>to include precisionDecimal if IEEE has not finalized its 754 revision, 
>and (3) not to include precisionDecimal if in the WG's opinion there 
>was inadequate implementation support for IEEE 754.  QT [reluctantly?] 
>accepted this decision.

At this point in time:

    o   Our Candidate Recommendation is expected to be published soon but
        has not yet been released.

    o   We understand the 754 revision is finalized and has been published.

    o   I'm not sure of the status of implementations.  I believe that
        Intel has a software implementation which they claim is sufficiently
        efficient that there is no need for a hardware implementation for
        their chips.  I believe at least one other hardware manufacturer
        is planning to make (or has already made?) a hardware implementation.

More or less duplicating that bug 3251 remark is, for your information, this
extraction from
    http://www.w3.org/Bugs/Public/show_bug.cgi?id=3120 :

>Proposed by the WG at the June 2007 f2f
>
>1 we retain pD in our spec
>
>2 when we enter CR, we mark pD as a feature at risk
>
>3 exit criteria for retaining pD after CR include (a) implementations 
>in the context of XML Schema, (b) uptake outside of XML Schema, (c) 
>state of the relevant IEEE specs


While not speaking for the WG, I suspect the WG will retain precisionDecimal in
the forthcoming Candidate Recommendation, with the promised "topic at risk"
mark unless the QT group agrees to its omission.  Assuming that the "topic at
risk" marking is present in the CR version of the spec, I hope you will again
make your feelings known with respect to the new datatype.
--
Dave Peterson
SGMLWorks!

davep@iit.edu


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Received on Monday, 23 February 2009 14:56:11 UTC

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