Browsing by Author "Li, Yong Yuan"
Now showing 1 - 1 of 1
- Results Per Page
- Sort Options
Item Concurrency control in distributed database systems : performance evaluation(1983) Li, Yong Yuan; Markenscoff, Pauline; Gardner, Gerald H. F.; Rusinkiewicz, Marek; Shen, Liang-ChiConcurrency control is the activity of coordinating concurrent accesses to a database in a multiuser database management system (DBMS). By preserving database consistency, concurrency control ensures that all alterations to the database are serializable (serializability is a situation in which concurrent operations on a database result in a computationaly equivalent state of the database, compared with executing the operations in a serial fashion). The concurrency control problem is very irrportant in a distributed DBMS (DDBMS) because: (1) users nay access data stored in mary different computers in a distributed system, and (2) a concurrency control mechanism at one computer cannot know about interaction at other computers. Concurrency control has been actively investigated for the past several years. Many concurrency control algorithms have been proposed for DDBMSs and several have been, or are being, inplemented. It is difficult to compare the performances of the many proposed algorithms. Naturally, each author proclaims his or her approach as the best, but there is little compelling evidence to support these claims. This thesis reviews the currently available algorithms concerning the concurrency control in DDBMS and evaluates their performance through simulation. The simulation software was developed to evaluate the performance of the DDBMS with different concurrency control mechanisms based on the timestamp technique. The results from the simulation are discussed and the conclusions are presented.