Multiple Transformations(Cont.) name,title name,title 6 dept_name=Music A year =2009 course year =2009 instructor dept_name-Music teaches course instructor teaches (a)Initial expression tree (b)Tree after multiple transformations Database System Concepts-6th Edition 1.17 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 6 1.17 ©Silberschatz, Korth and Sudarshan th Edition Multiple Transformations (Cont.)