Quiz 1 with Solution for Database Management System | EECS 484, Quizzes of Database Management Systems (DBMS)

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| EECS 484: Quiz 1 Page 1 of 3 | EECS 484, Winter 2009: Quiz # 1 Honor code pledge: I have neither given nor received aid on this exam. Name: SOLUTION (SAMPLE) Unigname: Signature: Question 1. Short Answers (18 Points) | a) Can a single database have more than one external schema? Briefly explain your answer. {2 points) Yes, Weean deAne an AMO TET number of Views atop & single logycal schema, b) Suppose we have an instance of a relation R, and we notice while scanning the tuples in R that there are no duplicate values in column A of R. i) Can we then infer that A is a candidate key for R? (I point) O Yes me No ii) Why or why not? . (2 points) We com nevec infer Taar an altrbute 19 a Ice Oy LOOKANG ak @ Singie insronce, CA ley iS propery, of all pessitote. mstances.) ¢) Consider the following ER diagram. Describe two reasonable translations to relational tables. (For this question, it is sufficient to simply state what columns are in each table. You do not need to provide the full SQL DDL.) (5 points) +3 (her +2 (second ©) Actor Movie COE Transiation 4 | Transiation #2. Actuc (aid »name) Acrov (aid , nome) Mowe Lmid , name, year) Movie Stars (mid, name, scary (aid, mid Year aid) | | |