If you make changes to a model object in the compare editor, the changes are automatically added to the model. You must save the model to save the changes. You can also choose not to save the changes, and generate delta DDL statements instead.
In this exercise, you will make changes to a server object. If you make changes to a server object in the compare editor, you must generate delta DDL statements for the changes and deploy them to the server to save the changes.
Before you perform the comparison, you should refresh the database metadata in the Data Source Explorer, to ensure that you are working with the most current information. This step is important if you are working in a team environment, and other team members are making changes to the database.
To compare and merge the changed physical data model with the original schema: