Database Normalization
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1
What is the purpose of database normalization?
To evaluate and correct table structures to minimize data redundancies.
2
What is the goal of normalization?
To reduce data anomalies.
3
Through what stages does normalization work?
Normalization works through a series of stages called normal forms: 1NF, 2NF, 3NF.
4
Which normal form is typically sufficient for most business database designs?
Third Normal Form (3NF).
5
Which two techniques are used together to produce a good database design?
Normalization and ER modeling.
6
What is a dependency diagram?
A diagram that depicts all dependencies within a table structure, helping visualize relationships among attributes.
7
What is a determinant in a table?
Any attribute whose value determines other values within a row.
8
What is Un-Normalized Form (UNF)?
A table containing repeating groups where multiple entries of the same type exist for a single key attribute occurrence.
9
What is the first step to convert a table to 1NF?
Eliminate repeating groups by presenting data in tabular format with single values in each cell and no nulls.
10
What is the second step to convert a table to 1NF?
Identify the primary key that uniquely identifies the attribute value.
11
What is the third step to convert a table to 1NF?
Identify all dependencies.
12
What defines a table in 1NF?
All key attributes are defined, there are no repeating groups, and all attributes are dependent on the primary key.
13
What is a partial dependency?
A dependency based on only part of the primary key.
14
What is the first step to convert a table to 2NF?
Write each key component on a separate line, making each component a key in a new table.
15
What is the second step to convert a table to 2NF?
Assign the corresponding dependent attributes to the new tables.
16
What defines a table in 2NF?
It is in 1NF and includes no partial dependencies.
17
What is a transitive dependency?
A situation where a non-key attribute determines another non-key attribute.
18
What is the first step to convert a table to 3NF?
Identify each new determinant in transitive dependencies and make it the primary key of a new table.
19
What is the second step to convert a table to 3NF?
Identify the dependent attributes for each new determinant and name the new table.
20
What is the third step to convert a table to 3NF?
Remove the dependent attributes in transitive relationships from the original tables.
21
What defines a table in 3NF?
It is in 2NF and contains no transitive dependencies.
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