9. The method of claim 3 , further comprising applying a subtree reconstruction, the subtree reconstruction including: selecting a record specified by the received expression, the record specifying a starting node in an Extended Markup Language tree representing the Extended Markup Language document; and constructing one or more subtrees under the selected starting node, while also preserving context information that connects newly constructed records with pre-existing records in the Extended Markup Language document.
9. The method of claim 3 , further comprising applying a subtree reconstruction, the subtree reconstruction including: selecting a record specified by the received expression, the record specifying a starting node in an Extended Markup Language tree representing the Extended Markup Language document; and constructing one or more subtrees under the selected starting node, while also preserving context information that connects newly constructed records with pre-existing records in the Extended Markup Language document. 16. The method of claim 9 , further comprising: examining the pending update list pertaining to the subtree; and if there are no pending updates in the pending update list that affect a lower level subtree with child records, avoiding reconstruction of the lower level subtree.