Where database diagrams reside in SSMS?
Before discussing features of SQL Server database diagrams it would be better to clarify a couple of messages that you may face while working with SQL Server database diagrams. Confirmation message while starting with database diagrams in SSMS The first time you click on the Database Diagrams folder of any user database in SSMS, you may get the following dialog. It is not an error, but just a permission seeking dialog to create some system stored procedures that are necessary to work with database diagrams. If you choose No then no procedures will be created and you will not be able to work with SQL Server database diagrams. If you choose Yes then the following system stored procedures would be created in your database and you will be able to work with SQL Server database diagrams.