Re: [xslt] key() in match pattern of xsl:key

[Jirka Kosek <jirka kosek cz>]

Joel E. Denny wrote:

> I've never used Saxon myself.  I've read that libxslt is one of (or the) 
> fastest XSLT 1.0 processor around.  Maybe this is one of the reasons?

With the respect to Daniel and its work, my experience is that libxslt 
is very fast when XSLT code doesn't contain "complex computations". This 
is case for the most of common stylesheets that are around. But I have 
several stylesheets that do various cases of a very complex grouping and 
Saxon is faster by magnitude then libxslt here. But for common 
transformations libxslt is faster because there is no JVM overhead.

In general, MSXML 4.0 is usually the fastest, but it runs only on 
Windows. Recently MS released MSXML 6.0 and there could be further speed 
optimizations.

Anyway if the performance is your main objective, you should benchmark 
several XSLT implementations and then choose your favorite implementation.

You can also try to optimize your XSLT code, xsltproc offers very useful 
--profile option to do this.

Back to your question, as keys are computed only once for the source 
document, there shouldn't be big performance penalty if you just remove 
key() from other keys' definitions.

				Jirka

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  Jirka Kosek     e-mail: jirka kosek cz     http://www.kosek.cz
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