摘要
PDM支持的产品设计是典型的长周期过程。解决PDM中对长周期设计事务的高度并发控制、保证设计数据的正确性和一致性是 PDM中的关键技术。本文分析了 PDM中设计事务的特点 ,研究了 PDM的嵌套事务模型以提高两段锁系统的并发性。提出了基于两段锁、两版本的并发控制机制 ,改进了常规的两段锁机制 ,并将设计数据和元设计数据分开。两版本机制在具有频繁并发读
Product design supported by PDM usually takes a long time. The design transaction model and high concurrency control mechanism which guarantee correctness and consistency is the key in PDM. This paper analyzes the property of PDM and a nested transaction model which can improve concurrency of two-phase locking mechanism. A two-phase locking two-version concurrency control mechanism is proposed and it improves two-phase locking. This concurrency control mechanism is divided into two mechanism. One takes care of the meta design data and the other takes care of the design data. The two-version mechanism is very effective in long duration transaction system with frequent concurrent read-write access.
出处
《机械科学与技术》
EI
CSCD
北大核心
2001年第4期630-631,637,共3页
Mechanical Science and Technology for Aerospace Engineering
基金
国家 8 63 /CIMS项目 (863 -5 11-93 0 -0 0 9)
