a kusa wrote:

> What little I know about using "//" is that the processor
>
checks a whole document when a "//element" is used.  If we are
> talking about
a really big document (few mB) this would
> definitely slow down the
transformation processing time.

> Right?

  No.  There is nothing telling so
in XDM, and when it comes to
optimization, that does not mean anything to
"theorize" about
possible behavior.  For an in-memory processor like Saxon,
that
reasoning is usually right, but I think Saxon has several
optimizations
for //, so maybe in some cases that could be the
opposite.

  For an XML
database in general that will be the opposite (for
instance // is usually
faster on eXist.)  Ok, there are not yet
an XSLT implementation supported
natively by an XML database, but
I predict that is going to change soon...
What I want to say is just: when it comes to efficiency, there
is no rule,
just measurements.

  Regards,

-- 
Florent Georges
http://www.fgeorges.org/