MC	The following relational model represents a HRM system of a consultancy firm. The primary keys are underlined while foreign keys are in italic font.<br><br>Consultant (<u>ConsultantID</u>, Date of Birth, Expertise)<br><br>Assigned_to (<u><em>ConsultantID</em>, <em>ProjectID</em></u>)<br><em>ConsultantID</em> refers to ConsultantID in Consultant<br><em>ProjectID</em> refers to ProjectID in Project<br><br>Project (<u>ProjectID</u>, Description, Type, <em>Company</em>)<br><em>Company</em> refers to Name in Company<br><br>Company (<u>Name</u>, Location)<br><br>Suppose a new consultant is hired and immediately assigned to a new training project at a new firm and to 2 other, already existing projects. How many rows (tuples) must be added to the database to reflect this change? 	3	incorrect	5	incorrect	1	incorrect	6	correct	
MC	Consider a data model for the Olympics storing information about countries and athletes.  There is a 1-N relationship type between country and athlete and an athlete always has to belong to exactly 1 country.  A relational data model containing only 1 table leads to:	Unnecessary replication of data about athletes.	incorrect	Unnecessary replication of data about countries.	correct	No unnecessary replication of data.	incorrect	Unnecessary replication of data about athletes and countries.	incorrect	
MC	Given the following relational model (primary keys are underlined, foreign keys in italics):<br><br>STUDENT(<u>studentnumber</u>, studentname, street name, street number, zip code, city)<br>ENROLLED(<u><em>student_number</em>, <em>course_number</em></u>)<br>COURSE(<u>course number</u>, course name)<br>PROFESSOR(<u>professor number</u>, professor name)<br>TEACHES(<u>course number, professor number</u>)<br><br>Which statement is CORRECT?	The model can be further normalized.	correct	The model does not allow a professor to teach multiple courses.	incorrect	The model does not allow a course to be followed by multiple students.	incorrect	The model does not allow a course to be taught by multiple professors.	incorrect	
MC	Which statement is NOT CORRECT?	A foreign key can be NULL.	incorrect	The Boyce Codd normal form is more strict than the third normal form.	incorrect	A prime attribute type is an attribute type that is part of a candidate key. 	incorrect	An EER aggregation cannot be mapped in a straightforward way to a relational model.	correct	
MC	Consider a data model for the Olympics storing information about countries and athletes.  There is a 1-N relationship type between country and athlete and an athlete always has to belong to exactly 1 country.  A relational data model containing only 1 table leads to:	Unnecessary replication of data about athletes.	incorrect	Unnecessary replication of data about athletes and countries.	incorrect	No unnecessary replication of data.	incorrect	Unnecessary replication of data about countries.	correct	
MC	Consider the following ER model for a course administration.<br><br><img class="img-fluid" src="http://www.pdbmbook.com/static/quiz/fig6_12.png"><br><br>Which statement is NOT CORRECT?	When mapping the ER relationship type enrollment between Session and Student to the relational model, a new relation needs to be introduced. The 4 cardinalities of this ER relationship type can be perfectly mapped to the relational model.	incorrect	When mapping the ER relationship type teaches between Session and Teacher to the relational model, a new relation needs to be introduced. The 4 cardinalities of this ER relationship type can be perfectly mapped to the relational model.	correct	When mapping the ER relationship type organizes between Course and Session to the relational model, the primary key "cnb" of the Course relation will be included as a NOT NULL foreign key in the Session relation. The 4 cardinalities of this ER relationship type can be perfectly mapped to the relational model.	incorrect	Both the ER and the relational model cannot enforce that a teacher can only teach sessions of courses for which he/she is qualified.	incorrect	
MC	Consider the following EER model <br><br><img class="img-fluid" src="http://www.pdbmbook.com/static/quiz/fig6_10.png"><br><br>Which statement is CORRECT?	The partial inheritance relationship between STUDENT and REPRESENTATIVE can be perfectly mapped to the relational model by the following two relations: STUDENT(StudentID, FirstName, LastName) and REPRESENTATIVE (S-StudentID, Email) whereby S-StudentID refers to StudentID in STUDENT.  	correct	When mapping the EER relationship type IS_ENROLLED between COURSE and STUDENT to the relational model, a new relation needs to be introduced. The relation is identified by GRADE as its primary key.	incorrect	When mapping the EER relationship type PARTICIPATE between GROUP ASSIGNMENT and STUDENT to the relational model, a new relation needs to be introduced. The 4 cardinalities of this EER relationship type can be perfectly mapped to the relational model.	incorrect	When mapping the EER relationship type INVOLVE between COURSE and ASSIGNMENT to the relational model, a new relation needs to be introduced. The 1..1 cardinalities of this relationship type cannot be enforced in the relational model.	incorrect	
MC	Given the following (normalized) relational model (primary keys underlined; foreign keys in italics):<br><br>EMPLOYEE(<u>SSN</u>, ENAME, EADDRESS, SEX, DATE_OF_BIRTH, <em>SUPERVISOR</em>, <em>DNR</em>)<br>SUPERVISOR: <em>foreign key, refers to</em> SSN in EMPLOYEE, <em>NULL value not allowed</em><br>DNR: <em>foreign key, refers to</em> DNR in DEPARTMENT, <em>NULL value not allowed</em><br><br>DEPARTMENT(<u>DNR</u>, DNAME, DLOCATION, <em>MGNR</em>)<br>MGNR: <em>foreign key, refers to</em> SSN in EMPLOYEE, <em>NULL value not allowed</em><br><br>PROJECT(<u>PNR</u>, PNAME, PDURATION, <em>DNR</em>)<br>DNR: <em>foreign key, refers to</em> DNR in DEPARTMENT, <em>NULL value not allowed</em><br><br>WORKS_ON(<u><em>SSN, PNR,</em></u> HOURS)<br>SSN: <em>foreign key, refers to</em> SSN in EMPLOYEE, <em>NULL value not allowed</em><br>PNR: <em>foreign key, refers to</em> PNR in PROJECT, <em>NULL value not allowed</em><br><br>Which statement is NOT CORRECT?	Every project is always assigned to exactly one department.	incorrect	Every employee must be always supervised by exactly one other employee.	incorrect	A department has always exactly one manager.	incorrect	An employee must work in the same department than he/she manages.	correct	
MC	Given the following relational model (primary keys are underlined, foreign keys are in italics)<br><br>BOOK(<u>ISBN</u>, title, pages, price, <em>publishername</em>)<br>AUTHOR(<u>authorname</u>, date_of_birth)<br>WRITES(<u><em>authorname</em></u>, <u><em>ISBN</em></u>)<br>PUBLISHER(<u>publishername</u>, streetnumber, streetname, <em>zipcode</em>)<br>CITY(<u>zipcode</u>, city)<br><br>The assumptions are: <ul><li>Each book has a unique ISBN number</li><li>Each author has a unique name</li><li>Each publisher has a unique name</li><li>A book can have multiple authors</li><li>An auther can write more than one book</li><li>A publisher can publish more than one book</li><li>A book can have multiple publishers</li><li>A publisher has only one address</li></ul>Which statement is CORRECT?	The relational model is in third normal form.	incorrect	The relational model is in first normal form but not in second normal form.	incorrect	The relational model is not in first normal form.	correct	The relational model is in second normal form but not in third normal form.	incorrect	
MC	The following relational model represents a HRM system of a consultancy firm. The primary keys are underlined while foreign keys are in italic font.<br><br>Consultant (<u>ConsultantID</u>, Date of Birth, Expertise)<br><br>Assigned_to (<u><em>ConsultantID</em>, <em>ProjectID</em></u>)<br><em>ConsultantID</em> refers to ConsultantID in Consultant<br><em>ProjectID</em> refers to ProjectID in Project<br><br>Project (<u>ProjectID</u>, Description, Type, <em>Company</em>)<br><em>Company</em> refers to Name in Company<br><br>Company (<u>Name</u>, Location)<br><br>Suppose a new consultant is hired and immediately assigned to a new training project at a new firm and to 2 other, already existing projects. How many rows (tuples) must be added to the database to reflect this change? 	1	incorrect	3	incorrect	6	correct	5	incorrect