lesson 5 Flashcards
is a database design technique that organizes
tables in a manner that reduces redundancy and dependency of
data.
NORMALIZATION
divides larger tables into smaller tables and links
them using relationships. Used to eliminate redundant (useless)
data and ensure data is stored logically.
Normalization
is the process of organizing data to
minimize redundancy in the design
of a relational database
management system (RDBMS)
refers to a series of recommended
steps taken to remove redundancy
and update anomalies from a
database design
Normalization
Problems that can occur in poorly
planned, unnormalized databases
where all the data is stored in one
table (a flat- file database).
Anomaly
Types of Anomalies:
Insert
Delete
Update
states that the domain of an attribute must include only atomic
values and that the value of any attribute in a row must be a single
value from the domain of that attribute
First Normal Form (1NF)
pertains to the built-in atomic data types
Atomic Values
ACID
(atomicity, consistency, isolation, and durability)
The table should be in the First Normal Form.
There should be no Partial Dependency.
Second Normal Form (2NF)
The attributes
which are used to form a candidate
key are called prime attributes.
Prime attributes
The attributes
which do not form a candidate key
are called non-prime attributes.
Non-Prime attributes
is a
concept that specifies the
relationship between two
sets of attributes where one
attribute determines the
value of another attribute.
Functional
Dependency
is a specific type of
dependency that happens in tables with
a composite primary key (a primary key
made up of two or more columns).
Partial dependency
3NF
Should be in second normal form
Should not have transitive dependency
