[xquery-talk] [Announce] XQilla version 1.1.0 released

John Snelson john.snelson at oracle.com
Tue Sep 4 17:29:03 PDT 2007


Jonathan Robie wrote:
> John Snelson wrote:
>> Andrew Welch wrote:
>>> On 9/4/07, David Carlisle <davidc at nag.co.uk> wrote:
>>>>> The point I was trying to make was that XQuery + XML DB should be able
>>>>> to select nodes far faster than XSLT + REST API, so the ideal
>>>>> combination is XSLT + XQuery extension function.
>>>> why does it have to be an extension function? XQuey and XSLT difer
>>>> mainly in surface syntax so if the XQuery engine can be hooked up to a
>>>> DB rather than an in memory tree, it's surely not impossible for the
>>>> Xpath that's embedded in XSLT to access a database in teh same way is
>>>> it?
>>>
>>> I was thinking about that (perhaps implementing Saxon's NodeInfo to
>>> work on the XQuery data model) but I don't think its needed... (and I
>>> may be talking nonsense there)
>>>
>>> All that's needed is a high level way to select from the db - thats
>>> it.  Whether it's through passing an XQuery to an extension function
>>> that returns each tuple as an item in a sequence, or using a REST
>>> interface that returns each tuple as element in a document, once you
>>> have that then the rest of the processing can be done using standard
>>> XSLT.
>>
>> I think the point here is that it will never be as fast in a stand 
>> alone XSLT processor as in one which can use the database's indexes 
>> and statistics to optimise the stylesheet.
>>
>> Since the XQuery data model is the same as the XSLT 2.0 data model, 
>> this all shouldn't be that hard.
> 
> For evaluating the path expressions, I agree with you. In general, 
> though, I don't think that XSLT templates that are triggered based on 
> recursive descent in document order is as easily optimized as XQuery 
> FLWOR expressions.

I agree, of course - it's not as easily optimized, but it's still 
possible to some extent or other.

John

-- 
John Snelson, Oracle Corporation
Berkeley DB XML:        http://www.oracle.com/database/berkeley-db/xml
XQilla:                                  http://xqilla.sourceforge.net


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