In advanced real-time distributed computing databases, the main performance criterion is to reduce the ‘deadline miss’ by the transactions; of course, consistency constraints also need to be satisfied. The goal of these applications is not to provide simply real-time transaction execution, but rather to provide a highly predictable, analysable, schedulable and reliable distributed computing platform to the users. The problem of resource conflicts amongst distributed real-time transactions and their handlings through various priority scheduling protocols highly affect the performance of the underlying applications. The past research works were mostly restricted to extend the traditional transaction processing techniques to resolve the issue of conflicts, and thus to improve the performance. The last review paper, largely on this issue, appeared in Shanker et al. (2008) [1]; since then many noteworthy algorithms have been described in the literature. Till date, no study was found discussing transaction processing techniques with data conflict issue in focus. Hence, our objective is to comprehensively discuss the state-of-the-art transaction scheduling protocols with an emphasis on the handling of execute–execute & execute–commit conflicts, and real-time optimistic concurrency control (OCC) protocols. The strengths and weaknesses of existing approaches are also discussed.

在先进的实时分布式计算数据库中，主要的性能标准是减少交易的“最后期限”。当然，还需要满足一致性约束。这些应用程序的目标不是提供简单的实时事务执行，而是为用户提供高度可预测，可分析，可调度和可靠的分布式计算平台。分布式实时事务及其通过各种优先级调度协议进行处理之间的资源冲突问题极大地影响了基础应用程序的性能。过去的研究工作大多局限于扩展传统的事务处理技术，以解决冲突问题，从而提高性能。上篇评论文章主要针对此问题，出现在Shanker等人。（2008）[1]；从那时起，文献中描述了许多值得注意的算法。直到现在，还没有发现讨论以数据冲突为重点的事务处理技术的研究。因此，我们的目标是全面讨论最新的事务调度协议，重点是处理执行-执行和执行-提交冲突以及实时乐观并发控制（OCC）协议。还讨论了现有方法的优缺点。我们的目标是全面讨论最新的事务调度协议，重点是处理执行-执行和执行-提交冲突以及实时乐观并发控制（OCC）协议。还讨论了现有方法的优缺点。我们的目标是全面讨论最新的事务调度协议，重点是处理执行-执行和执行-提交冲突以及实时乐观并发控制（OCC）协议。还讨论了现有方法的优缺点。