Design And Implementation Of A XML Data Updating Engine Seamlessly Integrated With Relational Database

With XML becoming the de facto standard format for representing and exchanging data, large repositories of XML documents are emerging on the Web. The widely spreading of XML document has proposed a new question for database community and thus more and more attention are payed on the management of XML data, including efficient query processing and updating Mechanism.The solution for the management of XML data based on the tranditional relational database is quite inefficient for large scale of XML document due to the difference between XML data model and the relational data model. The native XML solution conforms to the XML data model, but it has to reimplement the mature theories and technology in the tranditional relational database. The'863'project taken by the author's laboratory proposed a solution to seamless-integrate native XML engine in tranditional relational database. The new solution maintains the XML data features and makes full use of the modules in relational database, achieved good results.The main work of this thesis is a sub-topic of the'863'project:the updating of the XML data, seamlessly integrating the XML updating engine into the open source relational database PostgreSQL. This thesis summarizes two main tasks in designing and implementing of the XML updating engine. First, based on the studying of the W3C standard for XML updating'XQuery update facility 1.0' and the standard for operating XML data within relational database'SQL/XML:2003', the thesis proposes the syntax for XML updating meeting the users'hibits. Second, integrating XML updating function in each component of the PostgreSQL's processing engine.After updating a valid XML document, the database should assure that the document remains valid. Compared with tranditional entire valiation, the incremental approach can be more efficient, improving the performance of the XML updating engine. The thesis proposes an incremental approach for XML validation based on the simplified XML element sequence patters which can validate the XML document efficienctly. The experiment result shows that this approach performs better than the entire approach.