In this thesis, two schemes based on heuristics, which minimize the number of rollbacked transactions in partitioned distributed database, are proposed. the proposed schemes consist of two steps: elimination of two-cycles and elimination of long cycles. In the first scheme, long cycles may be transformed into two-cycles before two-cycles are eliminated, then remaining long cycles are eliminated by assigning weights to hem. The second scheme eliminates two-cycles without transformation, then eliminates long cycles by also assigning weights to the long cycles.
The performance of two proposed schemes as well as that of Davidson's scheme are compared in terms of the number of rollbacked transactions, using simulation approach. According to the simulation results, the first scheme outperforms Davidson's scheme and the second scheme outperforms the first scheme.
