MPX: A multiversion concurrency control protocol for XML documents

Abstract

With the rapid popularity of XML, especially in web-base applications, concurrency control of XML documents becomes an important issue. In this paper, we present MPX, a multiversion concurrency control protocol for XML documents, which is designed for synchronizing concurrent queries and modifications of XML documents stored in a native XML databases or XML document repository. Distinguished from other existing protocols, MPX ensures serializability, recoverability and cascadelessness. Furthermore, MPX also guarantees read-only transactions and update transactions will never block each other, which is especially beneficial for XML for queries on XML are much more frequent than updates. Plenty of experiments have also been carried out, confirming that MPX can ensure a better degree of concurrency and less rollbacks. © Springer-Verlag Berlin Heidelberg 2005.