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RE: [xsl] xpath // query

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> For example, is:
>
> select="A//C"
>
> any different to:
>
> select="A//B//C"
>
> when I know that <B> is *guranteed* to be there (both select the same
> nodes).  By adding the test for <B>, will it make the
> selection any faster?
>
No, it's likely to make it slower. The second expression will search all the
descendants of A looking for a B, and all the descendants of each B looking
for a C. So the descendants of a B will actually be visited (and usually
rejected) twice.

Of course the usual caveats apply - some processors may be doing
optimizations that I'm not aware of.

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx


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