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CSC 3800
Database Management Systems
Mid Term Review
Fall 2008
Dr. Chuck Lillie
Database Definitions
 Given a relational database
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



Identify the relations
Identify the attributes
Identify the tuples
Identify the database schema
Identify each relation schema
Database Definitions (example)
 Given a relational database
model
speed
ram
hd
price
1001
2.66
1024
250
2114
pc
1002
2.10
512
250
995
3001
printer
1003
1.42
512
80
478
B
2001
laptop
B
3002
printer
C
1003
pc
C
2002
laptop
C
2003
laptop
C
3003
printer
maker
model
type
A
1001
pc
A
1002
A
model
speed
ram
hd
screen
price
2001
2.00
2048
240
20.1
3673
2002
1.73
1024
80
17.0
949
2003
1.80
512
60
15.4
549
model
color
type
price
3001
true
ink-jet
99
3002
false
laser
239
3003
true
laser
899
Relational Algebra
 Identify and define relational algebra
operators
 Given a relational database

Write simple relational algebra queries
Relational Operators
 Selection: σC
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Core Relational Operators
 Theta-Join: ⋈C
R1 := σC (R2)
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 Projection: πL
R3 := R1 ⋈C R2
 Natural Join: ⋈
R1 := πL (R2)
 Product: Χ
 R3 := R1 Χ R2

R3 := R1 ⋈ R2
 Renaming: ρ
 R1 := ρR1(A1,…,An)(R2)
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Usual Set Operators
 Union: ∪
R3 := R1 ∪ R2
 Difference: —
 R3 := R1 — R2
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 Intersection: ∩

R3 := R1 ∩ R2
SQL
 SQL operators


Identify and define SQL operators
Given relational algebra operators, show the
equivalent SQL operators
 Given a relational database

Write simple SQL queries
Constraints and Triggers
 Keys & Foreign Keys
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
Define
Use SQL to declare for given relation
 Constraints


Define
Use SQL to declare for given relation
 Assertions


Define
Use SQL to declare for given relation