事务标识的研究与实现

Research and Implementation of Transaction Identifier

事务标识的分配是影响嵌套事务执行效率的重要因素之一．文章深入分析了在嵌套事务模型下，事务处理对事务标识的需求．以此为基础，提出了一系列实用有效的分配策略．其中，基于位的事务标识分配策略实际应用于自行研制的面向对象数据库系统ＫＤＯＯＤＢ（ＫｅＤａ ｏｂｊｅｃｔ ｏｒｉｅｎｔｅｄｄａｔａｂａｓｅ）中．

The assignment of transaction identifiers is one of the important factors influencing the per formance of nested transactions. In this paper, the requirements which the transaction process poses on the transaction identifiers under the nested transaction model are analysed. Based on this, a series of efficient and practical assignment strategies are proposed, and the bit based transaction identifier strategy is implemented in the object oriented database system——KDOODB (KeDa object oriented database). At last, the performance evaluation results are given.