Levels of Abstraction Physical level:describes how a record (e.g.,instructor)is stored. Logical level:describes data stored in database,and the relationships among the data. type instructor record ID string; name string; dept name string; salary integer; end; View level:application programs hide details of data types.Views can also hide information(such as an employee's salary)for security purposes. Database System Concepts-6th Edition 1.7 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 1.7 ©Silberschatz, Korth and Sudarshan th Edition Levels of Abstraction Physical level: describes how a record (e.g., instructor) is stored. Logical level: describes data stored in database, and the relationships among the data. type instructor = record ID : string; name : string; dept_name : string; salary : integer; end; View level: application programs hide details of data types. Views can also hide information (such as an employee’s salary) for security purposes