SXDGL: Snapshot Based Concurrency Control Protocol for XML Data

Nowadays, concurrency control for XML data is a big research problem. There are a number of researchers working on this problem, but most of the proposed methods are based on the two-phase locking protocol, which potentially leads to a high blocking rates in data-intensive XML-applications. In this paper we present and evaluate SXDGL, a new snapshot based concurrency control protocol for XML data. SXDGL completely eliminates data contention between read-only and update transactions. Moreover, SXDGL takes into account the hierarchical structure and semantics of XML data model determining conflicts between concurrent XML-operations of update transactions. The conducted evaluation shows significant benefits of SXDGL for processing concurrent transactions in data-intensive XML-applications.