嵌套事务可序列化调度中的隐式约束

Implicit Constraints in Serializable Schedules for Nested-Transactions

嵌套事务模型在现代数据库及分布式对象系统并发控制的理论研究和应用中具有重要地位 而父子事务之间的同步能力则是其中必不可少的组成部分之一 通常做法中 ,父事务对 (指定的 )单个子事务的同步可能触发可序列化调度的隐式约束 ,从而导致调度不可操作 通过分析隐式约束的产生原因 ,并将具有一定拓扑结构的嵌套事务定义为良构的 ,可以避免上述不可操作性

A nested transaction model is one of the most important parts of the theories and applications for modern databases and distributed object systems The synchronization between parent transaction and child transaction is the basic function of the model It is known that synchronization towards single child transaction, which is commonly used in other related works, may conflict with the implicit constraints of serializability and make the schedules inoperable After analyzing the reasons of implicit constraints, well formed nested transaction is defined to avoid the inoperability described above Finally, an algorithm is given, which can control the implicit constraints of well formed nested transaction and keep the serializability of schedules