1. A computer implemented method for implementing an updateable relational view over XML, data, comprising: generating the updateable relational view to respond to both SQL query operations and SQL update operations, the updateable relational view comprising one or more rows and one or more columns, wherein data within the one or more rows and the one or more columns are populated from underlying XML data that is not stored in a relational format; using a processor to generate an index table for mapping node addresses within the underlying XML data to the updateable relational view, an entry in the index table relates a node in the underlying XML data to an item of the data in the updateable relational view, wherein the entry in the index table comprises a column that includes a node address for the node in the underlying XML data; receiving a SQL update operation, wherein the SQL update operation includes an update is directed to the updateable relational view and not to the underlying XML data; identifying the item of the data for updating in the updatable relational view to implement the SQL update operation, the item of the data corresponding to the node in the underlying XML data; using the index table to identify the node address of the node in the underlying XML data; and updating the node at the node address within the underlying XML data to implement the update made to the updateable relational view by the SQL update operation.