Re: [xsl] Benefits of using xsl:key

[Wendell Piez <wapiez@xxxxxxxxxxxxxxxx>]

Jesper,

At 04:34 AM 11/5/2009, you wrote:
> The above is of cause only one type of dataset, but it shows to me
> that xsl:key can make a big difference and that fine tuning a
> template's match attribute can make a big difference.
>
> But it must all be done carefully, and it is necessary to analyze the
> dataset to find the best approach, and to test different approaches in
> order to find the best one (fast).

This thread is fascinating and informative: thanks for instigating it.

But I hasten to add that your findings are relevant to Saxon and may 
not (probably will not) be the same for other processors. There, use 
of key() may make less or (in many cases) even more of a difference.

This doesn't make the findings useless: on the contrary. But it does 
suggest, once again, that it is easy to overgeneralize when it comes 
to optimization. I can't count the times I have talked with students 
(usually fairly advanced ones) about contortions in their code, 
rationalized on the basis of optimization, which actually offered no 
effective advantages in practice. :-)

Cheers,
Wendell


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Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
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