XStamps: a multiversion timestamps concurrency control protocol for XML data

With the tremendous growth of XML data over the Web, efficient management of such data becomes a new challenge for database community. Several data management solutions, proposed in recent years, extend the capability of traditional database systems to meet the needs of XML data while alternative approaches introduce new generation databases, named as native XML database management systems. Although traditional databases have mature transaction management and concurrency control techniques, there is still a need to tailor techniques for native XML databases in order to deal with distinct characteristics of XML. In this paper, we propose XStamps, a multiversion timestamps concurrency control protocol for XML data, which is integrated in NextDB, a native XML database management system. XStamps is designed based on multiversion timestamps protocol, and additional features are added to enable the flexible control of the isolation level of transactions and allow such transactions to commit early. Experimental results have shown that XStamps works well with XML data and provides performance gain over other concurrency protocols like tree and two-phase locking.