Saxon

Legacy ID: #5400178 Legacy Poster: Michael Kay (mhkay)

There are two facilities that may help you here (both are in Saxon-SA only). The first is document projection: http://www.saxonica.com/documentation/sourcedocs/projection.html This does pretty-well exactly what you describe. It analyses a query to see which parts of the source document are required to evaluate the query, and then while building the source document, leaves out those parts of the source tree that aren't needed. This only works in an automated way for XQuery, not for XSLT, because XSLT is too dynamic to allow this kind of analysis. However, it's possible to use document projection with a manually-created filter, using the technique described on the page cited above. The second facility is streaming. This is even better, because it doesn't build a tree representation of the document at all - it's all processed on the fly. If necessary you can use a streaming transformation to construct a smaller intermediate document as the first phase of your processing, and then you can run a conventional transformation on this smaller document. The various facilities for streaming are described at http://www.saxonica.com/documentation/sourcedocs/serial.html In this case XSLT is currently rather better served than XQuery.