The Research On Concurrency-control Scheme Based On Finance Database In SAN

Internet finance software has become a contemporary trend, due to the development of Modern IT, the expansion of Group Company, the increasingly improvement of enterprise management technology, and the need of centralized financial management of financial department to administrative department;. The on-line office of financial affairs requires more about the database:higher speed of data transfer and stricter management of database transaction, especially for concurrency control.The thesis take concurrency control technology of financial database under the environment of SAN as study object, analyzes the concept of transaction and the features of ACID, discusses various locking techniques in concurrency control, and also puts forward an improved expanded multi-granularity locking prorotol based on 2PL according to the characteristics of financial database.Firstly, to establish high speed financial database system, we bring in the Storage Area Network (SAN). SAN database system has unparalleled superiority compared with traditional database system, namely decreasing transmission cost, improving the usability of the system and making it easy to enlarge the system, such as adding a new local data base or expanding a site.Secondly, introduce the concept of finance database transaction in SAN, characteristics of ACID and finance database, and then establish a financial database transaction model according to the above characteristics.Thirdly, it elaborates the various methods of concurrency control for the Storage Area Network, and based on that, puts forwards an improved concurrency control method:expanded multi-granularity locking prorotol based on 2PL, which is aimed to facilitate the frequency updating operation in the financial database. We extend the simple lock model, that is, adding five kinds of locks including Growth lock (G), scanning lock (C), intention share lock (IS), intention exclusive lock (Ⅸ) and intention growth lock (IG) based on the share lock (S) and exclusive lock (Ⅹ), and meanwhile establish the corresponding compatibility matrix. The user of the financial database can select the S lock, X lock, G lock and C lock in accordance with the requirements for the operation, and that is beneficial to improve the financial transactions. What's more, it also provides two solutions regarding to the problem of deadlock:to deadlock prevention and deadlock detection, and also the relevant algorithm.Fourthly, we offer a detailed realized scheme of the above concurrency control method, and use it in a simulation exercise to proves its feasibility, and its superiority to other basic 2PL protocol.