# Database Normalization and Page Ref Essay

Submitted By McMillon79
Words: 4252
Pages: 18

Database Processing, 13e (Kroenke/Auer)
Chapter 3: The Relational Model and Normalization

1) All relations are tables, but not all tables are relations.
Diff: 1 Page Ref: 120

2) A relation is a three-dimensional table.
Diff: 2 Page Ref: 121 Fig 3-4

3) A characteristic of a relation is that the cells of the relation hold a single value.
Diff: 1 Page Ref: 121-123 Fig 3-4

4) A characteristic of a relation is that the rows of a relation may hold identical values.
Diff: 2 Page Ref: 121-123 Fig 3-4

5) A relation is a table composed of columns and rows.
Diff: 1 Page Ref: 121-123 Fig 3-4

6) In relational terms as defined by E.F. Codd, a row is called a tuple.
Diff: 1 Page Ref: 123-124 Fig 3-9

7) In relational terms as defined by E.F. Codd, a column is called an attribute.
Diff: 1 Page Ref: 123-124 Fig 3-9

8) The columns of a relation are sometimes called tuples.
Diff: 1 Page Ref: 123-124 Fig 3-9

9) A tuple is a group of one or more columns that uniquely identifies a row.
Diff: 1 Page Ref: 123-124 Fig 3-9

10) A functional dependency is a relationship between attributes such that if we know the value of one attribute, we can determine the value of the other attribute.
Diff: 1 Page Ref: 124

11) If by knowing the value of A we can find the value of B, then we would say that B is functionally dependent on A.
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12) In functional dependencies, the attribute whose value is known or given is referred to as the determinant.
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13) Attribute Y is functionally dependent on attribute X if the value of attribute X determines the value of Y.
Diff: 2 Page Ref: 124-126

14) The functional dependency noted as A → B means that the value of A can be determined from the value of B.
Diff: 1 Page Ref: 124-126

15) In the functional dependency shown as A → B, B is the determinant.
Diff: 2 Page Ref: 124-126

16) Functional dependencies can involve groups of attributes.
Diff: 1 Page Ref: 124-126

17) Given the functional dependency (A, B) → C, the attributes (A, B) are referred to as a composite determinant.
Diff: 2 Page Ref: 124-126

18) Given the functional dependency A → (B, C), then it is true that A → B and A → C.
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19) Given the functional dependency (A, B) → C, then it is true that A → C and B → C.
Diff: 3 Page Ref: 124-126

20) Given the functional dependency A → B, then it is necessarily true that B → A.
Diff: 3 Page Ref: 124-126

21) A determinant of a functional dependency may or may not be unique in a relation.
Diff: 2 Page Ref: 128-129

22) A key is a combination of one or more columns that is used to identify particular rows in a relation.
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23) A row can be uniquely identified by a key.
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24) A combination key is a group of attributes that uniquely identifies a row.
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25) A key can be composed of a group of attributes taken together.
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26) It is possible to have a relation that does not have a key.
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27) A candidate key is one of a group of keys that may serve as the primary key in a relation.