Tree-Structure Diagrams (Cont.) Database schema is represented as a collection of tree-structure diagrams. single instance of a database tree The root of this tree is a dummy node The children of that node are actual instances of the appropriate record type When transforming E-R diagrams to corresponding tree-structure diagrams,we must ensure that the resulting diagrams are in the form of rooted trees. Database System Concepts,5th Ed. B.5 ©Silberschat乜，Korth and SudarshanDatabase System Concepts, 5 B.5 ©Silberschatz, Korth and Sudarshan th Ed. Tree-Structure Diagrams (Cont.) Database schema is represented as a collection of tree-structure diagrams. single instance of a database tree The root of this tree is a dummy node The children of that node are actual instances of the appropriate record type When transforming E-R diagrams to corresponding tree-structure diagrams, we must ensure that the resulting diagrams are in the form of rooted trees