The Primary Key Some organizations use a special numbering system. For example, many medical databases use the Social Security number to identify their patients. Each of us has our own unique, social security number. However, there are identity and security concerns about using SS numbers. In Microsoft Access the Primary Key should be an AutoNumber. As you add new records, Access will use the next number automatically. Databases crunch numbers quickly. If the Primary Key is text, such as a social security number, then each character must be evaluated by the database one at a time. This process is slow.   3. Try it: Review the Field Properties tblCustomers is still open in Design View. The Table Tools are available. Select the first Field: ID   What Do You See? The ID Field is indentified with a Key. It is Indexed (No duplicates.) It is also an AutoNumber.  Keep going, please. Exam 77-885: Microsoft Access 2010 2. Building Tables 2.4.1. Set Relationships: Define Primary Keys Table Tools->Design->Tools->Primary Key