5. The XDBMS of claim 3 , wherein at least one of the structure-based access privileges is attached to the XML documents comprising the respective structural element, and wherein the execution engine is further configured to evaluate the at least one structure-based access privilege.
5. The XDBMS of claim 3 , wherein at least one of the structure-based access privileges is attached to the XML documents comprising the respective structural element, and wherein the execution engine is further configured to evaluate the at least one structure-based access privilege. 6. The XDBMS of claim 5 , wherein the execution engine is further configured to scan a structure index.