When will you prefer to use Code First or DB First approach and why? If you have existing database already or you want to build your database first than other parts of the application then DB First approach to be used. If your prime focus is your domain classes and then create the database from your domain classes then Code first approach to be used. This ensures that you will have full control over code.
Where the viewstate is stored after the page postback? ViewState is stored in a hidden field on the page at client side. ViewState is transported to the client and back to the server, and is not stored on the server or any other external source.