Study Of Transaction Processing And Recovery Based On Log Of The Embedded Database

Embedded Database System (EDB) is a new technology of database system rising in recent years. Based on mature database technology and special embedded device, it implements the data's storage, organization and management on mobile devices and embedded devices.In this paper, an embedded database system is given. The EDB system is designed by module and hierarchy. The system has some good features like multi platform transplant and robust. The EDB system uses ARM develop and test environment andμC/OS-II real time operation system. It uses CF card as storage device and communicates with server by TCP/IP. The EDBMS realizes the functions of data management, SQL query, transaction process and recovery.The EDBMS deals with the transaction by the transaction execution task. It locks and releases data by the lock manage task. The 2PL protocol is used to ensure the serializable of the transation. A scheme which can dynamically changes lock granularity at running time according to the conflict of concurrent transaction is given. The scheme can balance the concurrency degree with the expenditure of the EDBMS. The scheme of concurrency control of the embedded real time database is introduced also.The embedded device is usually used in badly environment, so it would be in trouble and need to be recovered. The paper describes recovery techniques of EDB including log, checkpointing and reload and presents a EDB recovery system based on log server. Log server will reduce the expenditure of logging and checkpointing for EDB.