About replica visibility (MDB)
Note The information in this topic applies only to a Microsoft Access database (.mdb).
Replicas fall into three visibility types: global, local, and anonymous. A replica's visibility type determines several issues for the replica. For instance, a replica's visibility determines what type of replicas you can create from it, whether it can act as the Design Master in the replica set, and how it handles conflicts during synchronization. Visibility also determines which replicas that replica can synchronize with. You can't change a replica's visibility once you create the replica.
A global replica is the typical replica from which you can create all other types of replicas. Changes by a global replica are fully tracked and can be exchanged with any other global replica in the set. The global replica can also exchange changes with any local or anonymous replicas for which it becomes the hub. The Design Master is a global replica. From a global replica, you can create replicas that are global, local, or anonymous. Replicas created from a global replica are global by default.
Local replicas synchronize only with their hub, a global replica. They are not permitted to synchronize with other replicas in the replica set. Other local replicas are not aware of the local replica. Only the hub replica is aware of local replicas, and only from it can you schedule an exchange with a local replica. All replicas created from a local replica will also be local and have the same parent replica.
An anonymous replica can synchronize with its parent, a global replica. Anonymous replicas subscribe by way of the Internet, and do not have any particular identity, but instead proxy their identity for updates to the publishing replica. Internet/intranet synchronization works well when the replica set remains small (fewer than 10 individual replicas) and the number of data inserts and updates are limited. Anonymous replicas provide a way of getting around this "limit on number of replicas" problem. In addition, using anonymous replicas helps to keep out unnecessary topology information about replicas that participate only occasionally. All replicas created from an anonymous replica will also be anonymous and have the same parent replica. Anonymous replicas are recommended for use on the Internet for mass distribution because system-tracking information is not maintained, and replica size is reduced. A global replica will not be able to schedule synchronizations with an anonymous replica.
All local and anonymous replicas always have a priority of 0. Therefore, if any of their changes conflict with the global hub replica, the changes will automatically lose in any conflict resolution process. If they convey a non-conflicting change to the hub, the hub assumes authorship of the change.