A method, information processing system, and computer readable medium for improved representation of hierarchical documents, particularly a document encoded in Extended Markup Language (XML). The method loads a hierarchical document and stores into an addressable data structure such as a byte array. It then expands the addressable data structure lazily in response to navigations requested by a client. Nodes requested by the client are materialized, that is, they are created in memory, whereas other nodes are left unmaterialized in byte form. The method reduces the memory footprint of an XML document, as well as, improves query evaluation time and serialization time.