Object-based two-phased locking protocol in extolware persistence framework

Abstract

Locking schemes for an advanced database management system such as object-oriented database system are complex and difficult to implement. Many interesting locking schemes are investigated and examined in depth in this paper. The two phase multigranularity locking protocol proposed by Won Kin (1992) and many improved locking schemes proposed by other researchers to manage simple object, composite objects and dynamic methods invocation involve a large variety of lock modes and utilises a fairly complex algorithms. This paper examines these locking schemes and look at their working mechanisms in the first part of the paper. This research introduces an object-based two-phased locking protocol (OB-2PLP) for a transaction management system in the Extolware Persistence Framework. The locking schemes designed and implemented in the research are applied to simple objects, objects in an inheritance hierarchy, complex objects, collection of objects and relationships among objects. A discussion comparing the proposed locking scheme with several other locking schemes is presented