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INTRO. TO DATABASE MGMT. SYST.
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Given the following SQL query:
Film (FilmID, Title, Year, Genre, DirectorID)Director (DirectorID, Name, BirthYear, Nationality)Actor (ActorID, Name, BirthYear, Nationality)Film_Actor (FilmID, ActorID, Role)
SELECT f.TitleFROM Film fWHERE NOT EXISTS ( SELECT 1 FROM Film_Actor fa JOIN Actor a ON fa.ActorID = a.ActorID WHERE fa.FilmID = f.FilmID AND a.Nationality <> 'American');
Which of the following Relational Algebra expressions correctly represents this query?
Consider a relation R(M, N, O, P, Q, R) with the following functional dependencies: 1. MN → OP 2. O → Q 3. P → R 4. Q → M
The candidate key is MN.
Which functional dependency (or dependencies) violate BCNF?
Given the following SQL query:
Employee(eId, Name) Brand(bId, bName)Own(eId, bId)
SELECT O1.eId FROM Own O1 WHERE NOT EXISTS ( SELECT B.bId FROM Brand B WHERE NOT EXISTS ( SELECT * FROM Own O2 WHERE O2.eId = O1.eId AND O2.bId = B.bId ) );
Which of the following Relational Algebra expressions correctly represents this query?
Consider a relation R(M, N, O, P, Q, R) with the following functional dependencies: 1. M → N 2. N → OP 3. O → Q 4. P → R
Using the attribute closure method, is M → R derivable from the given FDs?
Given the following SQL query:
SELECT DISTINCT E.Lname, E.FnameFROM Employee E, Department DWHERE E.Dno = D.Dnumber AND D.Dname = 'Research';
Which of the following Relational Algebra expressions correctly represents this query?
Consider a relation R(M, N, O, P, Q, R) with the following functional dependencies: 1. MN → OP 2. O → Q 3. P → R
Which of the following functional dependencies must also hold?
Given the following SQL query:
Film (FilmID, Title, Year, Genre, DirectorID)Director (DirectorID, Name, BirthYear, Nationality)Actor (ActorID, Name, BirthYear, Nationality)Film_Actor (FilmID, ActorID, Role)
SELECT f.TitleFROM Film fJOIN Film_Actor fa1 ON f.FilmID = fa1.FilmIDJOIN Actor a1 ON fa1.ActorID = a1.ActorIDJOIN Film_Actor fa2 ON f.FilmID = fa2.FilmIDJOIN Actor a2 ON fa2.ActorID = a2.ActorIDWHERE a1.Name = 'Leonardo DiCaprio' AND a2.Name = 'Tom Hanks';
Which of the following Relational Algebra expressions correctly represents this query?
Consider a relation R(A, B, C, D, E) with functional dependencies: 1. A → B 2. B → C 3. CD → E
R is decomposed into R1(A, B, C) and R2(C, D, E).
Is this decomposition dependency preserving?
A relation is in 3NF if:
Given the following SQL query:
studinfo(studid, name, sex)enroll(studId, courseId)
SELECT DISTINCT e.courseIdFROM enroll eWHERE e.courseId NOT IN ( SELECT e1.courseId FROM enroll e1 JOIN studInfo s ON e1.studId = s.studId WHERE s.sex = 'male');
Which of the following Relational Algebra expressions correctly represents this query?