A Strategy for Data Consistency in Non-real-Time Connected DDBS

Considering the expense, the security of communication and demand in practice, a strategy is proposed, which propagates replicated data based on message and transaction-log table to update and maintain the database. It emphasizes that updates to a replica copy should been executed locally as much as possible avoiding using two-phase commit protocol operated directly on a remote copy in order to improve system performance. The message mechanism can prevent conflicts when two or more users update the same copy, and the transaction-log table is established to log up-to-date write transactions on a copy for a update propagation to other copies, avoiding access the original copy with large amounts of data.