Prepare for Conflict Resolution

Though you may take great care in designing your database and front-end application to avoid conflicts that may arise between multiple sites in a replicated environment, you may not be able to completely eliminate the possibility of conflicts. One of the most important aspects of replication is to ensure data convergence at all sites participating in the replicated environment.

When data conflicts occur, you need a mechanism to ensure that the conflict is resolved in accordance with your business rules and that the data converges correctly at all sites.

Oracle replication lets you define a conflict resolution system for your database that resolves conflicts in accordance with your business rules. If you have a unique situation that Oracle's pre-built conflict resolution methods cannot resolve, you have the option of building and using your own conflict resolution methods.

See Also: Oracle8i Replication for conceptual information about conflict resolution methods and detailed information about data convergence for each method.

Plan

Before you begin implementing conflict resolution methods for your replicated tables, analyze the data in your system to determine where the most conflicts may occur. For example, static data such as an employee number may change very infrequently and is not subject to a high occurrence of conflicts. An employee's customer assignments, however, may change often and would therefore be prone to data conflicts.

Once you have determined where the conflicts are most likely to occur, you need to determine how to resolve the conflict. For example, do you want the latest change to have precedence, or should one site over another have precedence?

As you read each of the sections describing the different conflict resolution methods, you will learn what each method is best suited for. So, read each section and then think about how your business would want to resolve any potential conflicts.

After you have identified the potential problem areas and have determined what business rules would resolve the problem, use Oracle's conflict resolution methods (or one of your own) to implement a conflict resolution system.