Patent ID: 8082492

Claim:
A method comprising: storing a new structured document data item into storage which stores a plurality of structured document data items each including a plurality of elements, each element of each structured document data item being associated with a node indicating a position of that element in a document tree of the structured document data item containing that element; acquiring a common structure including a plurality of nodes included in the structured document data items and the new structured document data item; acquiring, using a computer processor, a differential structure between the common structure and a structure of the new structured document data item, said differential structure being defined at least in part by an identifier of the new structured document data item and a numeral sequence indicating the differential structure corresponding to the new structured document data item; and storing an array of elements of the new structured document data item into the storage, the array being arranged based on the differential structure between the common structure and a structure of the new structured document data item, with a position of each element of the array corresponding to the position of the node associated with that element in the differential structure.