Database System Concepts Answers

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Ch03 Introduction to SQL
3.19

Ch01 Introduction
- 1.1
- 1.2
- 1.3
- 1.4
- 1.5
- 1.6
- 1.7
- 1.8
- 1.9
- 1.10
- 1.11
- 1.12
- 1.13
- 1.14
- 1.15
Ch02 Introduction to the Relational Model
- 2.1
- 2.2
- 2.3
- 2.4
- 2.5
- 2.6
- 2.7
- 2.8
- 2.9
- 2.10
- 2.11
- 2.12
- 2.13
- 2.14
- 2.15
- 2.16
- 2.17
- 2.18
Ch03 Introduction to SQL
- 3.1
- 3.2
- 3.3
- 3.4
- 3.5
- 3.6
- 3.7
- 3.8
- 3.9
- 3.10
- 3.11
- 3.12
- 3.13
- 3.14
- 3.15
- 3.16
- 3.17
- 3.18
- 3.19
- 3.20
- 3.21
- 3.22
- 3.23
- 3.24
- 3.25
- 3.26
- 3.27
- 3.28
- 3.29
- 3.30
- 3.31
- 3.32
- 3.33
- 3.34
- 3.35
Ch04 Intermediate SQL
- 4.1
- 4.2
- 4.3
- 4.4
- 4.5
- 4.6
- 4.7
- 4.8
- 4.9
- 4.10
- 4.11
- 4.12
- 4.13
- 4.14
- 4.15
- 4.16
- 4.17
- 4.18
- 4.19
- 4.20
- 4.21
- 4.22
- 4.23
- 4.24
- 4.25
- 4.26
Ch05 Advanced SQL
- 5.1
- 5.2
- 5.3
- 5.4
- 5.5
- 5.6
- 5.7
- 5.8
- 5.9
- 5.10
- 5.11
- 5.12
- 5.13
- 5.14
- 5.15
- 5.16
- 5.17
- 5.18
- 5.19
- 5.20
- 5.21
- 5.22
- 5.23
- 5.24
Ch06 Database Design Using the ER Model
- 6.1
- 6.2
- 6.3
- 6.4
- 6.5
- 6.6
- 6.7
- 6.8
- 6.9
- 6.10
- 6.11
- 6.12
- 6.13
- 6.14
- 6.15
- 6.16
- 6.17
- 6.18
- 6.19
- 6.20
- 6.21
- 6.22
- 6.23
- 6.24
- 6.25
- 6.26
- 6.27
- 6.28
Ch07 Relational Database Design
- 7.1
- 7.2
- 7.3
- 7.4
- 7.5
- 7.6
- 7.7
- 7.8
- 7.9
- 7.10
- 7.11
- 7.12
- 7.13
- 7.14
- 7.15
- 7.16
- 7.17
- 7.18
- 7.19
- 7.20
- 7.21
- 7.22
- 7.23
- 7.24
- 7.25
- 7.26
- 7.27
- 7.28
- 7.29
- 7.30
- 7.31
- 7.32
- 7.33
- 7.34
- 7.35
- 7.36
- 7.37
- 7.38
- 7.39
- 7.40
- 7.41
- 7.42
- 7.43
- 7.44
Ch08 Complex Data Types
- 8.1
- 8.2
- 8.3
- 8.4
- 8.5
- 8.6
- 8.7
- 8.8
- 8.9
- 8.10
- 8.11
- 8.12
- 8.13
- 8.14
- 8.15
Ch09 Application Development
- 9.1
- 9.2
- 9.3
- 9.4
- 9.5
- 9.6
- 9.7
- 9.8
- 9.9
- 9.10
- 9.11
- 9.12
- 9.13
- 9.14
- 9.15
- 9.16
- 9.17
- 9.18
- 9.19
- 9.20
- 9.21
- 9.22
- 9.23
- 9.24
- 9.25
- 9.26
Ch10 Big Data
- 10.1
- 10.2
- 10.3
- 10.4
- 10.5
- 10.6
- 10.7
- 10.8
- 10.9
- 10.10
- 10.11
- 10.12
- 10.13
- 10.14
- 10.15
- 10.16
Ch11 Data Analytics
- 11.1
- 11.2
- 11.3
- 11.4
- 11.5
- 11.6
- 11.7
- 11.8
- 11.9
- 11.10
- 11.11
- 11.12
Ch12 Physical Storage Systems
- 12.1
- 12.2
- 12.3
- 12.4
- 12.5
- 12.6
- 12.7
- 12.8
- 12.9
- 12.10
- 12.11
- 12.12
- 12.13
Ch13 Data Storage Structures
- 13.1
- 13.2
- 13.3
- 13.4
- 13.5
- 13.6
- 13.7
- 13.8
- 13.9
- 13.10
- 13.11
- 13.12
- 13.13
- 13.14
Ch14 Indexing
- 14.1
- 14.2
- 14.3
- 14.4
- 14.5
- 14.6
- 14.7
- 14.8
- 14.9
- 14.10
- 14.11
- 14.12
- 14.13
- 14.14
- 14.15
- 14.16
- 14.17
- 14.18
- 14.19
- 14.20
- 14.21
- 14.22
- 14.23
- 14.24
- 14.25
- 14.26
Ch15 Query Processing
- 15.1
- 15.2
- 15.3
- 15.4
- 15.5
- 15.6
- 15.7
- 15.8
- 15.9
- 15.10
- 15.11
- 15.12
- 15.13
- 15.14
- 15.15
- 15.16
- 15.17
- 15.18
- 15.19
- 15.20
- 15.21
- 15.22
- 15.23
- 15.24
- 15.25

3.19

List two reasons why null values might be introduced into the database.

[same question as that of 2.16] 1. When a value of an attribute is unknown. 2. When a value of an attribute does not exist