With the rapidly evolving XML technology and thereby ever-increasing number of XML documents, the importance of providing efficient tools for managing these enormous amounts of data is rising every day. Native XML database systems are such tools. Like other XML database systems they need indices in order to provide efficient and fast access to the data. These indices represent redundant data structures in the database and therefore have to be kept consistent, whenever the underlying base data is manipulated. Updating fragments of an XML document with automated, transparent, and efficient index maintenance is the central theme of this book. Author Harald Burger first analyses the two most prominent existing proposals for XML updates, namely the W3C's proposed extension of XQuery with operations for data manipulation and XUpdate. He then introduces an efficient and simple way to keep the indices in an XML DBMS consistent: the Simple Update API for the native XML database management system Infonyte DB. This book is addressed to professionals involved in XML and database development. It is also directed towards researchers in the XML area and beginning graduate or advanced undergraduate students of computer science.