动态多版本并行控制技术在主存数据库中的实现

Implementation of Concurrency Control Scheme Using Dynamic Multi-version in Main Memory Database Systems

针对主存数据库中以索引为基础的数据访问并行控制 问题提出了动态多版本技术，并考虑了记录数据和索引结点各自的多版本管理方案及相互联 系。实验证明该技术允许对数据库更新操作的并行执行，减少了对数据锁定的需求以及版本 维护所需的系统开销，同时保证了只读事务的无阻塞性，提高了系统的整体性能。该技术尤 其适用于以只读事务为主的应用。

In this paper, we present a concurrency control sch eme for index-based data access in main memory databases systems using dynamic multi-version mechanism. It not only considers the management of multiple vers io ns of both data items and index nodes, but also thinks about the interaction bet ween versioning and indexing. The expriment results show that this approach can improve the concurrency level of update operations, both the number of locking r equirements and the system overhead for version management are sharply reduced, and it ensures that read-only transactions can get response information without any block, so that improves the system performance. This technique is especiall y suitable for applications which involving many read-only transactions.