>An XSLT processor needs to keep the whole document in memory because the
>template for any node can reference nodes before and after it.
Search archives of this mailing list for the key words "pruning" and
"filtering". We do expect to eventually use stylesheet analysis to discard
unneeded portions of the incoming document, but that's still very much an
open area of research and isn't yet implemented in Xalan.
I don't know how Xalan-J's DTM model compares with Xalan-C's document model
in terms of storage overhead; might be an interesting experiment...
For now, you may well find that the best way to process those gawdawful
huge documents is to hand-code a SAX filter... though if your
transformation isn't fairly well localized, that may require just as much
storage or multiple passes through the source.
______________________________________
Joe Kesselman, IBM Next-Generation Web Technologies: XML, XSL and more.
"The world changed profoundly and unpredictably the day Tim Berners Lee
got bitten by a radioactive spider." -- Rafe Culpin, in r.m.filk
