Eastern Mediterranean University
Department of Computer
Engineering
CMPE 354 – Database Management Systems
Final Exam
2009 – 2010 Fall Semester
January 18, 2010
Name-Surname
:…………………..
Student No
:…………………..
:…………………..
Group
Instructor:
Assoc. Prof. Dr. Alexander CHEFRANOV
TIME: 110 MINUTES.
PLEASE ANSWER ALL QUESTIONS.
YOU CAN BRING IN ONE A4 SIZED SHEET OF HAND-WRITTEN NOTES TO THE EXAM.
PHOTOCOPIES ARE NOT ALLOWED !!!
MOBILE PHONES ARE NOT ALLOWED
GRADING
Task
1
2
3
4
5
6
7
8
9
10
Grade
TOTAL
1
A Library database shall allow answering the following Queries:
1. List the staff of the library including name, address, birthday, position, salary, enter
date, the name and position of a person who has accepted him.
2. List the history of a librarian’s position/salary changes, including the date of change
and name and position of a person who has approved this change. More than two
changes a year are not allowed.
3. List of readers of the library including name, address, enter date
4. List of the books a reader is currently keeping, the date he took and the date to return
them, the librarian’s name who has given the books. A reader is not allowed to take
more than 5 books at once.
5. List the history of a reader’s book borrowings including the date of taking and
returning, and the librarians’ names that have given and taken back the books.
6. List of the library books including author name, title, year of publication, publishing
company, ISBN number.
Task1 (10 points). Draw an E-R diagram for the Library database. It shall allow answering
Queries 1-6 above. Underline primary key attributes.
Id
name
Person
enterdat
e
pos
Addr
NewPos
Ch_date
NewSal
HistSt
a
Birthda
yy
sal
IdStaff
Staff
WhoApp
roved
Accepted
Is
a
BId
enterdat
e
TakeDa
te
IdRead
author
year
RetDate
Publish
er
ISBN
GiveReceive
HistRead
TakeDa
te
Book
borro
wed
Reader
title
RetDate
Bor#
2
Task 2 (10 points). Reduce the E-R diagram drawn by you in Task 1 to a relational schema.
Draw it as a schema diagram (tables connected with arrows showing foreign key
dependencies; each table is shown with its attributes; primary key attributes are underlined).
Person
Staff
HistSt
Id
Id
Id
Name
Ch_date
Book
Addr
enterdat
e
Pos
NewPos
BId
Birthda
Salary
NewSal
title
WhoAp
c
author
Reader
WhoAc
c
Id
Borrow
Enterdat
e
Reader
HistRea
d
RId
Bor#
Takeda
Book
year
Publish
ISBN
takedate
returnda
tr
librarian
Retdate
LibrGiv
e
LibrRec
Task 3 (10 points). Use the schema diagram drawn by you in Task 2 to write SQL DDL
statements for Library database of Task 1 including primary key, foreign key, and integrity
constraints.
Create table person(id char(10), name char(10), addr char(15), birthday date, primary key(id))
Create table staff(id char(10), enterdate date, pos char(15), salary money, whoAc char(10),
primary key(id), foreign key(id) references person, foreign key(whoAc) references staff)
Create table Histst(id char(10), ch_date date, newpos char(15), newsal money, whoapp
char(10), primary key(id, ch_date), foreign key(id) references staff, foreign key(whoapp)
references staff)
Create table book(Bid char(10), title char(10), author char(15), year date, publish char(10),
ISBN char(12), primary key(Bid))
3
Create table Reader(id char(10), enterdat date, primary key(id), foreign key(id) references
person)
Create table Borrow(Reader char(10), Book char(10), takedate date, returndate date, librarian
char(10). primary key(reader, book, takedate), foreign key(reader) references reader, foreign
key(book) references book, foreign key(librarian) references staff)
Create table HistRea(Rid char(10), bor# integer, takeda date, retdate date, librgiv char(10),
librrec char(10), primary key(rid, bor#), foreign key(rid) references reader, foreign
key(librgiv) references staff, foreign key(librrec) references staff)
Create assertion Two_changes_a_year_at_most check
Not exists(
Select *
From histst
Group by id, extract(year from ch_date)
Having count(whoapp)>2
)
Create assertion Five_books_borrowed_at_once_at_most check
Not exists(
Select *
From borrow
Group by reader, takedate
Having count(book)>5
)
Task 4 (10 points). Consider relational Library database defined by you in Task 3. Write
SQL expressions for Queries 1 and 2.
Query 1
Select p.name as p_name, p.addr, p.birthday, s.pos, s.salary, s.enterdate, b.name as boss,
s2.pos as boss_pos
From person p, staff s, staff s2, person b
Where p.id=s.id and s.whoac=s2.id and s2.id=b.id
4
Query 2
Select p.name as p_name, h.newpos, h,newsal, h.ch_date, b.name as boss, s.pos as boss_pos
From person p, histst h, staff s, person b
Where p.id=h.id and h.whoapp=s.id and s.id=b.id
Task 5 (10 points). Consider relational Library database defined by you in Task 3. Write
relational algebra expressions for Queries 3 and 4.
Query 3
 name,addr,enerdat (reader  person)
Query 4
 r.name,title,takedate,returndate,l.name( r ( person)  reader id reader borrow bookbid book librarianl.id l ( person))
Task 6 (10 points). Consider relational Library database defined by you in Task 3. Write
domain relational calculus expressions for Query 5.
{ rn, td , rd, lg, lt | (id , ad , bd )( id , rn, ad , bd  person & (bor )( id , bor, td , rd, lg, lt  histrea))}
Task 7 (10 points). Consider relational Library database defined by you in Task 3. Write an
SQL stored procedure for Query 6, taking one input parameter: author name, which may be
specified by the first several first letters as ‘Smi’ , so that ‘Smith’, ‘Smiles’, etc., match it.
Create procedure lib_books(in author_name)
Begin
Select *
From book
Where author like author_name||’%’
end
Task 8 (10 points). Consider relational Library database defined by you in Task 3. Use SQL
to create roles ‘librarian’ and ‘director’. The ‘librarian’ can register new readers and give/take
books to/from readers. The ‘director’ can admit new staff members, change their
position/salary, and he has full librarian’s rights. Give the role ‘director’ to Bob, and the role
‘librarian’ to Avi and Alice.
Create role librarian
Create role director
Grant insert on reader to librarian
5
Grant insert, update, select on person to librarian
Grant insert, update, select on borrow to librarian
Grant insert, update, select on histrea to librarian
Grant insert, update, select on person to director
Grant insert, update, select on staff to director
Grant insert, update, select on histst to director
Grant librarian to director
Grant director to Bob
Grant librarian to Avi, Alice
Task 9 (10 points). Give a lossless-join decomposition into BCNF of schema R=(A,B,C,D,E)
if the following set F of functional dependencies holds: F={A=>BE, CD=>E, D=>B, C=>E}.
Show all intermediate steps you make to come to the solution. Prove that the decomposition
you get is lossless-join.
A  ABE  R ,
hence, A=>BE violates BCNF condition, R1=(ABE), R2=(ACD). As far as
there are no more dependencies violating BCNF condition, R1, R2 is a BCNF decomposition
of R. It is lossless-join since A is a superkey for R1.
Task 10 (10 points). Give a lossless-join, dependency preserving decomposition into 3NF of
schema R=(A,B,C,D,E) if the following set F of functional dependencies holds: F={A=>BE,
CD=>E, D=>B, C=>E}. Show all intermediate steps you make to come to the solution. Prove
that the decomposition you get is lossless-join and dependency preserving.
Find candidate keys:
ACD is a candidate key since
ACD  R, AC   ACBE  R, AD  ADBE  R, CD  CDEB  R
Finding Fc. Check F for extraneous attributes.
Assume B is extraneous in A=>BE. Then F’={A=>E, CD=>E, D=>B, C=>E}. F=>F’ is
trivial. Show that F’=>F. Under F’: A  AE and B is not got. Hence, B is not extraneous.
Assume E is extraneous in A=>BE. Then F’={A=>B, CD=>E, D=>B, C=>E}. F=>F’ is
trivial. Show that F’=>F. Under F’: A  AB and E is not got. Hence, E is not extraneous.
Assume C is extraneous in CD=>E. Then F’={A=>BE, D=>E, D=>B, C=>E}. F’=>F is
trivial. Show that F=>F’. Under F: D  DB and E is not got. Hence, C is not extraneous.
Assume D is extraneous in CD=>E. Then F’={A=>BE, C=>E, D=>B, C=>E}. F’=>F is
trivial. Show that F=>F’. Under F: С   CE and E is got. Hence, D is extraneous.
6
Hence, Fc={A=>BE, C=>E, D=>B }
Using 3NF decomposition algorithm
R1=(ABE)
R2=(CE)
R3=(DB)
Since no one of the schemas contains a candidate key,
R4=(ACD)
R1, R4 is a lossless-join decomposition since
R1  R4  A  R1
R1, R4, R2 is a lossless-join decomposition since
( R1  R 4)  R 2  R 2  R 2
R1, R4, R2, R3 is a lossless-join decomposition since
( R1  R 4  R 2)  R3  R3  R3
The decomposition is dependency preserving since
Fc  Fc1  Fc2  Fc3
7