Planning Offline Capabilities

See Also

Through offline publications, you can provide users with a local copy of the database and make it possible for them insert, delete, or update data without a connection to the online database server. After connecting to the network again, users can synchronize the local copy of the solution with the online copy.

For example, if a salesperson visits a client, a laptop that has an offline copy of the team solution can be used to enter client issues or take client orders. When the salesperson returns to the office and connects to the network, the online database can be updated with the changes made to the local version.

For users to take a solution offline, they must set up their local computers with appropriate prerequisites. For details, see Setting Up the End-User Client Computer.

Before creating an offline publication

1. Install offline replication support for the solution. For details, see Installing Offline Support for the Team Solution.
   
   
2. Create roles for your team solution, and assign users to these roles as appropriate. For details, see Assigning Users to Database Roles.
   
   
3. Create workflow processes for your team solution, and specify any actions that cannot be performed offline. For details, see Adding a Workflow Process to your Solution.

Then, you can create your offline publications. For details, see Making Data Available Offline.

For an example of how to implement offline support, see Offline Support in the Issue Tracking Solution.

Offline Publications Guidelines

When creating your team solutions to work with offline publications, consider the following issues:

• When a main table is included in a publication, a column called rowguid is added to the table. This column is used in synchronization. One side effect of this addition is that any existing Insert statements, which explicitly list column names, must be updated to include this new column.
  
  
• Merge replication does not support timestamp columns. Timestamp values are generated automatically by the local server and are guaranteed to be unique within a specific database only. Therefore, it is impossible for a change to the timestamp value created on one server to be applied to the timestamp column on another server. You must remove the timestamp column from any table you want to publish using merge replication. For more information, see “merge replication” in SQL Server Books Online.
  
  
• The names of publications and the database objects contained in publications cannot contain leading or trailing spaces.

Offline Permissions and Database Updates

When designing your database and offline publications, remember the user has system administrator privileges in the offline version of the local database and, therefore, has the ability to make changes while offline.

The actions the user performs while offline are tracked and stored. Security is enforced when the user attempts to synchronize the changes when returning online. The permissions are enforced based on the user’s database role.

Then, Offline actions are applied to the server database, but only actions the user has permissions to perform are implemented on the server. Changes the user has made in the offline database that are not permitted are not implemented on the server.

Offline Configuration Considerations

When enabling your team solution for offline use, you must make the following decisions:

• How do you want changes to the offline database synchronized with the online database—one record at a time or all records at once? For details, see Defining Synchronization Methods.
  
  
• What default method of conflict resolution do you want? For details, see Allowing Users to Resolve Conflicts.
  
  
• Can multiple users work offline? If yes, you must enable identity partitioning. For details, see Enabling Identity Partitioning.
  
  
• What data do you want to include in the offline publication? For details, see Making Data Available Offline.