First Normal Form (Cont'd) Atomicity is actually a property of how the elements of the domain are used. Example:Strings would normally be considered indivisible Suppose that students are given roll numbers which are strings of the form CS0012 or EE1127 If the first two characters are extracted to find the department,the domain of roll numbers is not atomic Doing so is a bad idea:leads to encoding of information in application program rather than in the database. Database System Concepts-5th Edition,Oct 5,2006 7.9 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 5 7.9 ©Silberschatz, Korth and Sudarshan th Edition, Oct 5, 2006 First Normal Form (Cont’d) Atomicity is actually a property of how the elements of the domain are used. Example: Strings would normally be considered indivisible Suppose that students are given roll numbers which are strings of the form CS0012 or EE1127 If the first two characters are extracted to find the department, the domain of roll numbers is not atomic. Doing so is a bad idea: leads to encoding of information in application program rather than in the database