What Is Normalization.define 1NF,2NF And 3NF?


6 Answers

Neha Agrawal Profile
Neha Agrawal answered
Normalization is related to statistics,  it is the process of identifying statistical error in repeated data. Completing this process will show how a specific variable can affect the data which will ultimately show the underlying characteristics of the multiple sets of data when can then be compared. There are different variations of normalization including Quantile normalization, which refers to property.

1NF also known as First Normal Form or Minimal Form is a form used in database normalization. 1NF refers to a database table that adheres to a certain minimum set of criteria. This means that the table is a clear and precise representation of a particular relation and it will not be part of repeating groups. For example, a 1NF table will not have a top to bottom order in the rows, as well as no left to right ordering in the rows. In addition there are no identical rows and all columns are regular.

Second Normal Form or 2NF is a 1NF table that has no composite candidate keys, which are keys that consist of more than one attribute. If this is the case then the table will automatically be defined as a 2NF table. However, a 2NF table can be deemed as a 3NF or Third Normal Form table if every non-prime attribute of the table is not directly dependant on every candidate key in the table. It is important to understand that a non-prime attribute does not belong to any candidate key of the table.
Katie Harry Profile
Katie Harry answered
Normalization is the process of successively reducing relations with anomalies to produce smaller and well structured relations.

First normal form (1NF) is a relation that has a primary key and in which there are no repeating groups.

Second normal form (2NF) a relation in first normal form in which every non key attribute is fully functionally dependent on the primary key.

Third normal form (3NF)a relation that is in second normal form and has no transitive dependencies.
Anonymous Profile
Anonymous answered
NORMALIZATION is process efficiently organizing data into database....there is main to part of normalization.
I. Eliminating redundant data
ii. Only storing related data..
1NF( first normalization form): It is the process of eliminating duplicate forms from same data and creating the separate tables for each group of related data and also to identify each row with a unique column oe set of columns
2NF(second normalization form): Meet all requirement of 1NF& removing subset of data that apply to multiple rows of tables and place them in separate tables.
3NF(third normalization form): Meeting both above forms and removing duplicate data.
Anonymous Profile
Anonymous answered
First normal form (1NF). This is the "basic" level of normalization and generally corresponds to the definition of any database, namely:

    * It contains two-dimensional tables with rows and columns.
    * Each column corresponds to a sub-object or an attribute of the object represented by the entire table.
    * Each row represents a unique instance of that sub-object or attribute and must be different in some way from any other row (that is, no duplicate rows are possible).
    * All entries in any column must be of the same kind. For example, in the column labeled "Customer," only customer names or numbers are permitted.

Second normal form (2NF). At this level of normalization, each column in a table that is not a determiner of the contents of another column must itself be a function of the other columns in the table. For example, in a table with three columns containing customer ID, product sold, and price of the product when sold, the price would be a function of the customer ID (entitled to a discount) and the specific product.

Third normal form (3NF). At the second normal form, modifications are still possible because a change to one row in a table may affect data that refers to this information from another table. For example, using the customer table just cited, removing a row describing a customer purchase (because of a return perhaps) will also remove the fact that the product has a certain price. In the third normal form, these tables would be divided into two tables so that product pricing would be tracked separately.
Anonymous Profile
Anonymous answered
A relation is said to be in first normal form if and only if each attribute of the relation have only value.

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