摘要
针对嵌入式实时数据库对数据库系统结构的要求,提出一种基于BerkeleyDB数据库引擎、运行于VxWorks平台的ERTDB系统结构.在模型中引入Shell层,事务管理器获得事务命令后将处理转入Shell层,在调用BerkeleyDB相应的函数前Shell层与并发控制器进行同步通信,由并发控制器确定该事务命令是否可以执行.对于并发控制器,通过事件驱动的方式来实现并发控制协议,协议结构体的设计可以更方便地使用不同的并发协议;采用定时地根据正在运行的事务实时性和截止期为各事务动态分配VxWorks下的任务优先级的机制实现时限控制器功能.实验表明,该系统的读写速度可以满足千万级的数据处理要求.
In consideration of embedded real-time database＇s requirement on database system structure ,the embedded real- time database （ERTDB）structure running on VxWorks platform and BerkeleyDB was proposed. First,shell layer was added. The transaction manager handed on the results to Shell layer when it got the transactions. Before calling the BDB＇s functions ,the synchronization communication between Shell layer and concurrency control manager was completed ,and the concurrency control manager determined whether the transactions could be executed. For the concurrency control manager, the concurrency control protocol was realized through the event-driven approaches. The design of protocol structure makes it more convenient to use different concurrency protocols. Each transaction was dynamically assigned VxWorks＇s task priority according to the running real-time transaction ,which realized the timer controller functions. The test result shows that the system＇s read-write speed is fully able to meet the 10 million data-processing requirements.
出处
《天津科技大学学报》
CAS
2010年第3期66-70,共5页
Journal of Tianjin University of Science & Technology
基金
天津科技大学自然科学基金资助项目(20070223
20080208)
