The Technology Research On Database Offline Concurrency Control

The advanced database systems application areas demand that the database systems have both high performance concurrency processing ability and satisfy the demands of high reliability,so concurrency control is one of the most important contents in Database Management System (DBMS),lock and serializable schedule are two main strategy for concurrent operation of database. However, even if all of transactions are executed at the serializable level, the application may fail when executed concurrently due to potential offline concurrency problems. This thesis mainly research on the problem of offline concurrency control, use the TCFG algorithm to detect the offline concurrency conflict lurked in the application programs, and an innovative solution based on offline concurrency conflict controller is proposed to solve offline concurrency problems. The offline concurrency conflict controller has been implemented using Visual studio 2005 on Windows 2000 system platform.In this thesis, the problem of the offline concurrency is firstly analyzed, and the architecture of the offline concurrency conflict controller is also discussed, an original algorithm for offline concurrency conflict prevention is proposed base on it, then mainly research on the key technology of offline concurrency conflict controller. At the end of the thesis, the design and implementation of offline concurrency conflict controller are introduced in detail.The offline concurrency conflict controller is actually dispatches the concurrency and shared problem shift for business processing, using access disposal, reasonable arrange transaction to be executed, by avoiding the implementation of conflict schedule to reduce the risk of offline concurrency conflict. Theory analysis and emulated experiment results showed that the proposed algorithm enhanced data consistency and reliability, and the solution can reduce the risk of offline concurrency conflict effectively.