Download Assignment 1 - Al Akhawayn University

Al Akhawayn University
School of Science and Engineering
CSC 3326 Database Systems, Summer 2003
Individual Homework assignment 1
(Deadline 16th June, 11:00, in paper form, no email)
Question 1 (6pt/30)
1.1 Suppose that you have an application area to model: When and why will apply the file
system or database system?
1.2 Why are entity integrity and referential integrity important in a database and give examples?
1.3 Why do we need to create many indexes on DB?
1.4 Give your own examples for the following relationships: 1-1, 1-M, and M-N
1.5 Why do we need to convert an ER model to relational model?
1.6 Suppose that you have the Entity Relationship model shown below, convert it into
Chen model
DRIVER
drives
TRUCK
During some time interval, a DRIVER can drive many different TRUCKs
and any TRUCK can be driven by many DRIVERs
Question 2 (6/30)
Suppose that you are using the following a database composed of the two tables shown below:
Table name: DIRECTOR
Table name: PLAY
2.1 Identify the primary key(s).
2.2 Identify the foreign key(s).
2.3 Do the tables exhibit entity integrity and/or referential integrity? Answer Yes or No, then
explain your answer.
2.4 Draw the Entity Relationship model.
2.5 Draw the relational schema to show the relationship between DIRECTOR and PLAY.
2.6 Suppose you wanted quick lookup capability to get a listing of all the plays directed by a
given director. What table would be the basis for the index table, and what would be the index
key?
Question 3 (3 pt/30)
Suppose that you are using the following database composed of the two tables:
Table name: Customer
Table name: SALES REP
a. Join these tables by using the 3 steps.
Question 4 (5/30)
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
1. A relational database data is organized as
a.
a collection of records.
b.
a collection of common fields.
c.
elements.
d.
relations.
2. A database model is a collection of logical constructs used to represent the data structure and
relationship. Database models are
a.
conceptual.
b.
conceptual and Relationship.
c.
conceptual and Implementation.
d.
implementation and relationship.
3. The network database model depicts a set of _______________relationship.
a.
many to one
b.
one to one
c.
one to many
d.
many to many
4. A table can be logically connected to another table by defining a
a.
hyperlink.
b.
common field.
c.
primary key.
d.
foreign key.
5. Each relation must have
a.
a primary key.
b.
a secondary key.
c.
a foreign key.
d.
a logical key.
Question 5
(10/30)
True/False
5.1 In a relational table, each value in a column must conform to the same data format.
5.2 In a relational table, each column represents an attribute, and each column has a distinctive
name.
5.3 A database that supports users across many departments is known as a workgroup database.
5.4 A single user database can support one user at the same time.
5.5 Data anomalies exist because a change in any field value can't be made in multiple places.
5.6 Data redundancy is reduced 100% by database files.
5.7 Knowing the minimum and maximum number of entity occurrences is very useful at the
application software level.
5.8 The external model is DBMS-dependent and hardware-independent.
5.9 The Crow's Foot model does not identify multivalued attributes.
5.10
Cardinality expresses the specific number of entity occurrences associated with an
occurrence of a related model.