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From Daniel John Debrunner <...@apache.org>
Subject Re: XML type description - possible changes?
Date Tue, 29 Aug 2006 17:30:42 GMT
Army wrote:
> Daniel John Debrunner wrote:
> 
> <snip old XML type text>
> 
>>
>> That seems wrong to me, the use of "store Unicode character-based", any
>> implementation details are not important here. Also the use of "large"
>> is not relevant, what about small XML documents?
> 
> 
> I have to admit, I'm guilty of copy-paste here.  The current
> documentation for the CLOB type has the following sentence, which is the
> root of the questions raised in this email:
> 
> <begin quote>
> 
> A CLOB (character large object) value can be up to 2,147,483,647
> characters long. A CLOB is used to store unicode character-based data,
> such as large documents in any character set.
> 
> <end quote>
> 
> I copied that as my starting point and failed to clean it up...sorry.
> 
>> Looking at the other type definitions it seems something like this would
>> match, though it seems unwieldy.
>>
>> "XML provides for storage of Extensible Markup Language (XML) documents,
>> that conform to the SQL/XML definition of a well-formed
>> XML(DOCUMENT(ANY)) value."
> 
> 
> I agree, I think this is a better wording.  My one reservation is that
> the XML type can also be used transiently for XML values that are not
> well-formed documents.  In particular, the XMLQUERY operator returns a
> value of type XML that is not guaranteed to be XML(DOCUMENT(ANY)).
> 
> So while I agree with the new text proposal, I think it'd be good (or at
> least, more accurate) to mention that XML is not restricted to "storage
> of ... well-formed XML(DOCUMENT(ANY)) values"; it also provides for
> transient use of XML(SEQUENCE) values, which may or may not be
> well-formed XML(DOCUMENT(ANY)) values.

I agree with your reservation. It can also be applied to most, if not
all of the data type decriptions. Many talk about "providing storage"
but they can all be used for transient types.

Dan.



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