Coexistence of Implicit Lock and Explicit Lock for Page Lock Mechanism on Object Database Management System ShusseUo

In most object database management systems, concurrency control is implemented by using locking. The functionality and performance improvement of locking is one of the most important issue to improve transaction processing capability. ShusseUo is the parallel and distributed object database management system for PC or workstation clusters. The locking mechanism for ShusseUo is designed to allow coexistence of the implicit lock and explicit lock mechanism. Naive users who want to write application programs using the implicit locks and expert users who want to write application programs which require high performance transaction processing can access a same database at the same time without performance degradation. This paper presents the design and implementation of implicit lock and explicit lock mechanism for ShusseUo