实时数据库系统中的嵌套事务

Nested Transactions in Real time Database Systems

传统的原子事务是由一个平坦数据库操作序列组成的，事务的执行具有ＡＣＩＤ（Ａｔｏｍｉｃｉｔｙ，Ｃｏｎｓｉｓｔｅｎｃｙ，Ｉｓｏｌａｔｉｏｎ，Ｄｕｒａｂｉｌｉｔｙ）特性．然而，在实时应用环境下，这些却不太适用．该文提出了一种支持实时应用的嵌套事务模型，给出了嵌套事务的特性及正确性标准。

In the traditional transaction model, a transaction is a flat sequence of the database operations and the executions of transactions have the ACID(Atomicity, Consistency, Isolation, Durability) properties. But under the real time environment, these appear unsuitable. A nested transaction model to support real time applications is proposed and the properties and the correctness stanadards of nested transactions are presented in this paper. The priority assignment strategies and the concurrency control protocol for nested real time transactions are discussed with emphasis.