The justification is that SAXON 6 has a bug exactly in this
place. Building node-set is slow. Because SAXON 6 uses the
same data structure for node-set and RTF, building RTF is
slow too, giving ten-fold difference in performance with XT
on some documents in cases which are difficult to predict.
No, you've got it completely the wrong way around! Saxon uses a
different data structure for RTFs from its normal tree model, and it's
this different data structure that has a bug in it!
But you can't prove anything from bugs, especially performance bugs.
They can happen anywhere at any time. This one happened because RTFs are
usually small, which meant that a scalability problem in this area
didn't show up in all the standard performance tests; the same bug in
the tree model used for input documents would have shown up very
quickly.
Michael Kay
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list