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CS 281 Fall 2010
Homework 1
Due date: October 25, 2010.
1. [32 pts]
Consider the following relations:
Student(sid
, sname, department)
Course(cid
, cname, instructor)
Enroll(sid, cid, year
, grade)
Give the Relational Algebra expressions for the queries given below:
(a)
Find the names of the students who have been registered for the courses with names
“Database Systems” or “Manufacturing Systems”.
(b)
Find the names of the students who have taken any course taught by Prof. Jones.
(c)
Find the names of the students who have never taken any course taught by Prof. Jones.
(d)
Find the names of the students with the lowest grades in course CS281 in year 2010.
2.
[24 pts]
Given that relation R(a,b) contains the tuples {(1,2),(2,3),(3,1)} and S(b,c)
contains the tuples {(1,2),(1,3),(2,3),(2,1)}. Provide the results (both the schema and the
tuples) of the following Relational Algebra
operations:
(a)
Cross Product of R and S.
(b)
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 Fall '08
 David

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