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A Lock Manager for Collaborative Processing of Natively Stored XML Documents

Michael P. Haustein

Kaiserslautern University of Technology
Dept. of Computer Science (AG DBIS)
P.O. Box 3049, 67653 Kaiserslautern, Germany
e-mail: haustein@informatik.uni-kl.de

Theo Härder

Kaiserslautern University of Technology
Dept. of Computer Science (AG DBIS)
P.O. Box 3049, 67653 Kaiserslautern, Germany
e-mail: haerder@informatik.uni-kl.de

Full paper (PDF version)

Abstract

Today, neither transactional provisions, in general, nor concurrency control, in particular, of DBMS-based processing are tailored to the specific needs of large and collaboratively used XML documents. Existing DBMSs more or less offer strictly serialized operations on them. To gain great progress in this area, we have implemented the XTC testbed as an (O)RDBMS-connected native XML database management system to empirically explore fine-granular concurrency control on XML documents which is, at the same time, adjusted to the specific needs of their APIs. In this paper, we primarily develop locking protocols for direct and navigational access to individual nodes of XML documents. Furthermore, we outline the implementation concepts for our lock manager which realizes this functionality in XTC, before we characterize its performance behavior on a rich spectrum of locking protocols using selective measurements in real applications.

in: Proc. 19th Brazilean Symp. on Databases (SBBD 2004), Brasilia, Oct. 2004, pp. 230-244.