摘要
针对多用户并发操作环境中,多个用户程序同时存取同一数据,相互干扰导致丢失修改数据、不能重复读和读未提交的数据等问题,提出了解决并行操作下写/写和读/写数据库冲突的并发控制方法。该方法采取封锁机制,即某事务向系统发出请求,便将数据对象加锁并对锁以管理,实现其控制。在多用户环境下,Oracle8i数据库的后台并发控制与处理机制涉及事务隔离机制、封锁机制及强制锁释放等处理方法。PowerBuilder 7.0前端并发控制则可通过Key and Updatble Colums,并遵循抢先修改的事务设计原则。
In multi-user parallel operating environment, multi-users access the same data at the same time and interfere each other leads to losing amended data, do not repeatable read or read non-put data. So the parallel control method was given to solve write/write and write/read database collision in parallel oprating. The lock mechanism was used in this method, some transaction sent a request for locking certain data object to the system, and then manage the lock to realize the control. Under multi-user environment, the parallel control and processing mechaniems in Oracle8i refer to transaction isolation mechanism, locking mechanism and lock releasing mechanism. The front end parallel control in PowerBuilder 7.0 was realized by Key and Updatble Colums, and the transaction was designed according to preemptive amending principle.
出处
《兵工自动化》
2003年第2期33-36,共4页
Ordnance Industry Automation
