Relational database systems are increasingly used to manage XML
documents, especially for data-centric XML. In this paper we present a new
approach to efficiently manage document-centric XML data based on a generic
relational mapping. Such a generic XML storage is especially useful in data
integration systems to manage highly diverse XML documents. We focus on
efficient insert operations, support of streamed data and fast retrieval of
document fragments. Therefore we introduce a new numbering scheme called
DLN (Dynamic Level Numbering) and several variants of it. A performance
evaluation based on a prototypical implementation demonstrates the high
efficiency of DLN.