RE: Re[2]: correct use of keys?

Microsoft XML Parser 4.0 July 2001 Technology Preview 

http://msdn.microsoft.com/downloads/default.asp?url=/downloads/sample.asp?ur
l=/msdn-files/027/001/677/msdncompositedoc.xml

Bullet point 4:
'Substantially faster XSLT engine. Our tests show about x4, and for some
scenarios x8, acceleration (except the known serious performance bug for
xsl:keys).'


> -----Original Message-----
> From: Kevin Burges [mailto:xmldude@xxxxxxxxxxxxxxxx]
> Sent: 13 September 2001 12:34
> To: Michael Kay
> Subject: Re[2]:  correct use of keys?
> 
> 
> Michael + Thomas:
> 
> >> I have a stylesheet which, when run on a 10MB doc turns it 
> into a 30MB
> >> doc in ~600 seconds.
> >> Even for such a large doc, this seems like along time 
> given my machine
> >> is a 1.33GHz Athlon, 256MB.
> 
> MK> It seems a long time to me, too. Which processor are you 
> using? Are you
> MK> getting thrashing due to shortage of memory?
> 
> I'm using the latest MSXML 4 (July?). Toward the end of the
> transformation there is a small amount of swapping going on, but
> certainly not what I'd call thrashing. For the majority of the time
> there is virtually no drive access at all.
> 
> 
> MK> better off doing a preprocess of the document in which 
> elements whose name
> MK> contains 'field' are given an extra attribute, 
> field="yes", and then use
> MK> this attribute in the second phase. In any case, I 
> suspect that you are not
> MK> interested in all nodes whose name contains 'field', but 
> only in elements
> MK> whose name contains 'field'. Replacing "node()" by "*" 
> will speed things up
> MK> a bit.
> 
> I tried this in a couple of stages:
>         Changing "node()" to "*" made no difference
>         Using "field = 'yes'" instead of "contains(....)" made no
>         difference
> 
> I also tried using specifically
>   "*[(name() = 'field') or (name() = 'datefield') or (name() =
>   'computedfield')]
> This also made no difference.
> 
> 
> In fact, when I used the "field = 'yes'" method, the Win2k task
> manager said my program was using up to 175MB memory, where
> previously I had not seen it above 105MB.
> 
> 
> TP> Then I suggest that you temporarily change the stylesheet so it
> TP> outputs only one node where it has to use one of the keys, and see
> TP> how long it takes. This will check whether compiling the
> TP> stylesheet and building the key indices is taking an inordinately
> TP> long time.
> 
> I tried this, and the index was generated instantly. Presumably
> because the document that is being indexed is fairly small.
> 
> 
> TP> Another thing is whether you are testing out the transfomation in
> TP> an environment where the result is displayed in a browser (like
> TP> XML Cooktop or XML Spy).
> 
> No, I'm transforming programatically in VB so that's not an issue.
> 
> 
> One thing I did notice is that if the keys are empty (I had made a
> mistake), the transform only takes 60 seconds as opposed to 600.
> 
> This suggests surely that there must either be something wrong with
> the way I am using the keys (so they are being ineffectual), or MSXML
> has a very poor implementation of keys. Any other suggestions???
> 
> -- 
> groovy baby,
>  Kevin                    mailto:xmldude@xxxxxxxxxxxxxxxx
> 
> ++++++++++++ Cool music - http://burieddreams.com/marshan
> ++++++ Attitude Webzine - http://burieddreams.com/attitude
> 
> 
>  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
> 

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list