5. The method of claim 1 : at least one node of at least one document further comprising a node value; the query node path specifying at least one query node value; and identifying the matching documents comprising: identifying at least one matching document having at least one matching node comprising, for respective query node values of the query, at least one path node in the node path of the matching node that matches the query node identifier and a node value matching the query node value.
5. The method of claim 1 : at least one node of at least one document further comprising a node value; the query node path specifying at least one query node value; and identifying the matching documents comprising: identifying at least one matching document having at least one matching node comprising, for respective query node values of the query, at least one path node in the node path of the matching node that matches the query node identifier and a node value matching the query node value. 6. The method of claim 5 : the query node path specifying a query node value range; and identifying the matching documents comprising: identifying at least one matching document having at least one matching node comprising, for respective query node values of the query, at least one path node in the node path of the matching node that matches the query node identifier and a node value within the query node value range.