Speculative Distributed Transaction Processing

In this paper, we propose speculative distributed transaction processing (SDTP) strategy, in which, a transaction releases the locks on the data objects immediately after the completion of its execution and starts commit processing. By accessing both original values and updated values immediately after the transaction's execution, the waiting transaction speculatively carries out alternative executions, and starts commit processing. Before the end of commit processing, the transaction that has carried out speculative executions retains the appropriate execution based on the termination decisions of preceding transactions. Using SDTP approach con icting transactions can be processed in parallel without violating the serializability criteria. This approach is free from cascading aborts. The speculative transaction processing approach does not require extra number of messages since every message is piggy backed with the messages of commit processing. However, it needs both extra processing power and main memory to support speculative executions. The proposed approach can be tuned according to the resources available in the system. Through simulation experiments, it has been shown that the proposed approach considerbly reduces the response time and increases the throughput in the case of higher resource con icts and the longer transmission times.