XOM API for Processing XML with Java

["Michael Kay" <mike AT saxonica.com>]

Thanks very much for this: very useful data.

I'm not greatly surprised that Saxon is slower over DOM than over other data
models, but it's nice to have confirmation. I could speed it up, for example
by assuming DOM level 2 support, but I don't feel strongly motivated to do
so. If you excluded the time for compiling the XPath expression, and only
measured the execution time, the difference would be even greater. 

(For many of these expressions, I suspect the cost is dominated by
compile-time costs. In fact, many of them will be be completely evaluated at
compile time.)

>From my own point of view, I would love to see how these figures for Saxon
compare with running Saxon over its native (TinyTree) data model: I would
expect these figures to be considerably better, but I'd like to know how
much better. Apart from anything else, this would set a target for improving
the XOM wrapping layer.

The query that failed under Saxon involves (1 div 0) which is not legal in
XPath 2.0 except in backwards compatibility mode (it becomes an integer
division: to get a floating point division you need 1.0e0 div 0, or if you
want it to run under both 1.0 and 2.0 you can write number(1) div 0). At
present Saxon supports XPath backwards compatibility mode when running
within XSLT but not otherwise - this is something I must add.

Michael Kay
http://www.saxonica.com/


> -----Original Message-----
> From: xom-interest-bounces AT lists.ibiblio.org 
> [mailto:xom-interest-bounces AT lists.ibiblio.org] On Behalf Of 
> shirasu hiroyuki
> Sent: 19 January 2005 07:22
> To: xom-interest AT lists.ibiblio.org
> Subject: Re: [XOM-interest] Performance of Java XPath engines
> 
> From: shirasu hiroyuki <hirsh AT s9.dion.ne.jp>
> Subject: [XOM-interest] Performance of Java XPath engines
> Date: Wed, 19 Jan 2005 16:16:14 +0900 (JST)
> 
> <snip/>
> 
> > For details see my page:
> > 
> >   http://www.k2.dion.ne.jp/~hirsh/xpath/engineComparions-en.html
> 
> Sorry for typo. This means
> http://www.k2.dion.ne.jp/~hirsh/xpath/engineComparison-en.html
> 
> 
> Thanks,
> --
> shirasu hiroyuki(hirsh AT s9.dion.ne.jp)
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