Real-time Main Memory Database System Research Articles

A partition checkpoint strategy based on data segment priority

A partition checkpoint strategy based on data segment priority is presented to meet the timing constraints of the data and the transaction in embedded real-time main memory database systems (ERTMMDBS) as well as to reduce the number of the transactions missing their deadlines and the recovery time. The partition checkpoint strategy takes into account the characteristics of the data and the transactions associated with it; moreover, it partitions the database according to the data segment priority and sets the corresponding checkpoint frequency to each partition for independent checkpoint operation. The simulation results show that the partition checkpoint strategy decreases the ratio of transactions missing their deadlines.

A performance study of concurrency control in a real-time main memory database system

Earlier performance studies of concurrency control algorithms show that in a disk-resident real-time database system, optimistic algorithms perform better than two phase locking with higher priority (2PL-HP). In a main memory real-time database system, disk I/Os are eliminated and thus more transactions are enabled to meet their real-time constraints. Lack of disk I/Os in this environment requires concurrency control be re-examined. This paper conducts a simulation study to compare 2PL-HP with a real time optimistic concurrency control algorithm (OPT-WAIT-50) for a real time main memory database system, MARS. The results show that OPT-WAIT-50 outperforms 2PL-HP with finite resources.