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Assignment1 solution

L
Lee Taemin

2010-1 Database. assignment #1 (relation algebra) Taemin Lee. Dataknow Lab. Computer Science Education Dept. Korea University.

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Database System Conceps : CH2 Exercises and solutions
Relation Algebra Six basic operators select: project: union: set difference: cartesian product: x rename: Additional Operations Natural join: Aggregation: Outer Join: Division:
Problem 2.1.
Problem 2.1.a. (Street = M_street City = M_city) ( relation) t1 employee manages t2 manager (manager_name, m_street, m_city) (employee) Person_name Street City Manager_name M_street M_city Person_name Street City Manager_name Manager_name M_street M_city
Problem 2.1.a. t1 employee manages t2 manager (manager_name, m_street, m_city) (employee) (person_name) (Street = M_street City = M_city) (t1 t2) Person_name Street City Manager_name M_street M_city Person_name Street City Manager_name Manager_name M_street M_city
Problem 2.1.a. t1 employee manages t2 manager (manager_name, m_street, m_city) (employee) (person_name) (Street = M_street City = M_city) (t1 t2)
Problem 2.1.b.
Problem 2.1.b. wrong answer! Set different operation attribute 螳 狩伎 ! person_name company_name salary person_name
Problem 2.1.c.
Problem 2.1.c.
Problem 2.1.c.
Problem 2.3.a.
Problem 2.3.a. wrong answer! Update 覲伎 襯 譟一 !
Problem 2.3.b.
Problem 2.5.a.
Problem 2.5.b. & 2.5.c
Problem 2.5.d. & 2.5.e
Problem 2.6.
Problem 2.6.a.
Problem 2.6.a.
Problem 2.6.b. & 2.6.c
Problem 2.7.a.
Problem 2.7.b.
Problem 2.7.b.
Problem 2.7.c.
Problem 2.8.a. t1 account_number count(customer_name)
Problem 2.8.b. account customer 1 customer 2 customer 3
Problem 2.8.b. account customer 1 customer 2 customer 3 depositor 1 account 1 customer 1 depositor 2 account 2 customer 2 depositor 3 account 3 customer 3
Problem 2.8.b. account customer 1 customer 2 customer 3 customer 1 customer 2 customer 3 account 1 account 2 account 3 depositor 1 account 1 customer 1 depositor 2 account 2 customer 2 depositor 3 account 3 customer 3
Problem 2.8.b. account customer 1 customer 2 customer 3 customer 1 customer 2 customer 3 account depositor 1 account 1 customer 1 depositor 2 account 2 customer 2 depositor 3 account 3 customer 3
Problem 2.8.b.
Problem 2.9.a. t1 t2 company_name count-distinct(person_name) max(count-tistinct(person_name)
Problem 2.9.b.
Problem 2.9.b.
Problem 2.9.c.
Problem 2.11.a
Problem 2.11.b.
Problem 2.11.c. common mistake! t1 name 譟伎讌 ! empno count_distinct(isbn) empno name office age isbn title authors publisher date
Problem 2.11.c. & 2.11.d
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Assignment1 solution