Homework 1
(Maximum 60 points)
Upload the homework onto Blackboard as one PDF or Word document file. Due end of day (11:59 p.m.) Friday September 11, 2020
1. (30 points) [Research: three-level schema architecture] Discuss the three-level schema architecture of database systems. Specifically, answer the following three questions:
(a) What is the three-level schema architecture of database systems, and what is the goal of the
layered approach?
(b) What is logical data independence and how is it achieved in the three-level schema
architecture?
(c) What is physical data independence and how is it achieved in the three-level schema
architecture
Reference: Section 2.2 of the textbook; feel free to use other resources (e.g., Internet web sites) as well; cite the resources in your answers. Note that the term ¡°conceptual schema¡± in Section 2.2 does not necessarily mean entity-relationship schema we study as the ¡°conceptual schema¡± in class; it may rather mean the ¡°database schema¡± understood by the DBMS.
2. (30 points) [Conceptual schema design: Movie database] Textbook Exercise 3.33 (no lab exercise). Show the designed ER diagram using the notations like the ones in Figure 3.2 (not the ones in Figure 3.20). You are welcome to use any software tool to draw the ER diagram; if you draw it by hand, make sure the diagram is clearly readable. Points will be deducted for diagrams that are not following the notations as in Figure 3.2 or not clearly readable.
Last modified: September 4, 2020