Set Subscription Priority

Replication Wizard Help

Replication Wizard Help

Set Subscription Priority

When you create a subscription, you can either assign it a priority value or use the Publisher as a proxy for the Subscriber when resolving conflicts.

A subscription with an assigned priority value is called a global subscription; a subscription using the priority value of the Publisher is called a local subscription. This table summarizes the main differences and uses of each type.

Type Priority Value Used
Global. Assigned by user. When you want different Subscribers to have different priorities.
Local (includes anonymous). 0.00, but the Publisher acts as a proxy for data changes after the Subscriber synchronization with the Publisher. When you want all Subscribers to have the same priority, and the first Subscriber to merge with the Publisher to win the conflict.

Anonymous subscriptions are helpful when you expect to have a large number of Subscribers and you do not want to keep track of them at the Publisher/Distributor.

When you change a row in a global subscription, the subscription priority is stored in the meta data for the change. This priority value travels with the changed row as it merges with changes at other Subscribers. This assures that a change made by a higher priority subscription does not lose to a change made by a subscription with a lower priority.

If a row is changed in a local subscription, no priority is assigned to the change until the row merges with the other changes at a Publisher. During the merge process at the Publisher, the changes from the Subscriber are assigned the priority of the Publisher and travel with that priority as it merges with changes at other Publishers and Subscribers. In a sense, the Publisher assumes authorship of the change.

Global subscriptions provide a greater number of options and allow for greater sophistication to a conflict resolution scheme than local subscriptions. Using global subscriptions ensures that priority values are preserved throughout the enterprise.

Global subscriptions can also be specified as alternate synchronization partners for subscriptions to this publication. (Alternate synchronization partners are specified in the Publication Properties dialog box.)

Local subscriptions are also appropriate (and usually required) in a topology with several levels, where Subscribers are leaf nodes. In these topologies, any nodes that republish data must be global Subscribers; local Subscribers can be used only at the leaf nodes.

Select Use the Publisher as a proxy for the Subscriber when resolving conflicts if you want this to be a local subscription.

Select Use the following priority . . . and then enter a priority number for the subscription if you want this to be a global subscription.

See Also

Merge Replication Conflict Detection and Resolution

Subscriber Types and Conflicts