A general concurrency control scheme can work either as a locking scheme or as a timestamp ordering scheme by varying the strict level of the scheme. By adjusting the strict level, the performance of the general concurrency control scheme can be close to that of a locking scheme and that of a timestamp ordering scheme. In this thesis, the optimal strict level is obtained and then the performance of general concurrency control scheme with the optimal strict level is compared to that of the locking scheme and that of the timestamp ordering scheme using simulation experiments.
According to the simulation results, it turns out that in the low conflict case the optimal strict level is found to be 1, whereas in the high conflict case the optimal strict level is the dame as the degree of multiprogramming. Simulation results also show that the timestamp ordering scheme (two phase locking scheme) outperforms the general concurrency control scheme using only the strict level whose value is 1 (the degree of multiprogramming). But by keeping the optimal strict level, the performance can be maintained at least the performance of the locking scheme or the timestamp ordering scheme.
