ACCESS CONTROL MODEL AND LABELLING SCHEME FOR EFFICIENT QUERYING AND UPDATING XML DATA

As XML continues to be utilised in various fields of information technology, an urgent need for managing XML documents is being felt. Considering day-to-day operations such as updating, accessing and/or querying XML documents, these tasks need to be accurate, quick to carry out, easy to use and more importantly safe from unauthorized accesses. This requires an integrated scheme that can facilitate query processing and determine what kind and/or part of information can be displayed, updated and/or modified by different types of users. In order to facilitate query processing for XML data, several path indexing, labelling, and numbering schemes have been proposed. However, if there is frequent demand for XML data to be updated, most of these approaches will need to re-compute existing labels, which is rather time consuming. Some other existing approaches tried to solve this problem by reserving spaces or reserving codes to minimize the cost of re-labelling. However, when al