Homework 1: EC2, ER, and Relational Data Model
DSCI 351 – Spring 2025
Due: 11:59pm, 2/3, 2025, Monday
Points: 100
1.​ [20 points] Explain what each of the following Linux OS commands does. 2 points each
question.
1)​ ls -a
2)​ ls -l
3)​ mkdir
4)​ cd
5)​ nano
6)​ cat
7)​ rm
8)​ rmdir
9)​ cp
10)​mv
2.​ [Modeling-1, 40 points]
1)​ [20 points] Draw an ER diagram (electronically) to capture the following entities and
their relationships. Be sure to indicate the multiplicity of relationships (including if it
is at most one or exactly one for many-one or one-one relationships), and key(s) for
each entity set.
●​ Book: isbn, title, and year
●​ Author: id, name, affiliation
●​ Publisher: id, name, address, phone
Assume that a book must have one and only one publisher.
2)​ [20 points] Convert the above ER diagram into a relational model. For each relation,
state its attributes and key(s).
3.​ [Modeling-2, 40 points]
1)​ [20 points] Draw an ER diagram (electronically) to capture the following entities and
their relationships. Be sure to indicate the multiplicity of relationships (including if it
is at most one or exactly one for many-one or one-one relationships), and key(s) for
each entity set.
●​ Fire station: id, name, address, phone
●​ House: id, address, owner
●​ Fire fighter: id, name, rank
Your diagram needs to capture the relationships between fire station and fire fighter,
and between firefighter and house.
3)​ [20 points] Convert the above ER diagram into a relational model. For each relation,
state its attributes and key(s).
SUBMISSION INSTRUCTIONS:
1.​ Submit a PDF file with answers/screenshot for the above questions.
2.​ LATE submissions will not be accepted.