RE: XPath Push/Pull Was: RE: Incremental transformations with Xalan and performance issues?

> 
> I am curious how you decide which to choose, is this just 
> down to the context/structure of the expression or are 
> there other criteria involved?
> 
You start in one mode or the other depending how the
expression/query/stylesheet is invoked, and you only change modes when you
have to.

At present all tree construction is in push mode, and path expressions are
always in pull mode, but many other expressions such as conditional and FLWR
expression work either way. For singleton expressions there's essentially no
difference.

Michael Kay
http://www.saxonica.com/