Computer Science 455

First Hour Exam

Name _______________________________

Friday, Feb. 20

100 pts.

I. Some basics.

a. (10 pts.) Give a brief definition of a database management system, including some descriptive detail (i.e., a one sentence answer will probably not receive full credit).

b. (10 pts.) Give a description of the essential features of the relational model, remembering that a data model includes both an underlying model (structure) and a series of integrity constraints.

c. (15 pts.) Give a definition of three of the following 5 terms (only the first three terms defined will be graded)

key

foreign key

entity integrity

referential integrity

data independence

d. (5 pts.) Briefly, why is a relational database called relational?

e. (15 pts.) List, and briefly describe, the three basic file organizations (not a database question).

f. (15 pts.) Consider the following entity-relationship diagram:

A is the key to T1, and C is the key to T2. From this diagram, construct a relational schema, clearly identifying keys and any foreign keys in each table..

Questions following are with respect to the SPJ database:

S(SNO, SNAME, STATUS, CITY)

P(PNO, PNAME, COLOR, WEIGHT, CITY)

J(JNO, JNAME, CITY)

SPJ(SNO, PNO, JNO, QTY)

2.

a. (10 pts.) Using both EASYALG and SQL, write queries to find the names of PARIS projects (jobs).

EASYALG

SQL

b. (10 pts.) Using both EASYALG and SQL, write queries to find the project (job) numbers (J#) of projects (jobs) using blue parts.

EASYALG

SQL

c. (10 pts.) (SQL only) Write a query to find the names of projects (jobs) using a blue part supplied by a PARIS supplier.