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Database Normalizatio

is a process used to organize a database into tables and columns.
By limiting a table to one purpose you reduce the number of duplicate data contained within your database.

To minimize duplicate data.
to minimize or avoid data modification issues.
to simplify queries.
Data Duplication and Modification Anomalies
Duplicated information presents two problems:
It increases storage and decrease performance.
It becomes more difficult to maintain data changes.
Database normalization fixes the situations are modification anomalies.
There are three modification anomalies that can occur:
Insert Anomaly
There are facts we cannot record until we know information for the entire row. so in order to create the record, we need provide a primary key.

In this case we have the same information in several rows. If we don’t update all rows, then inconsistencies appear.

You can eliminate or reduce the issues of sorting and searching anomalies by separating the data into different tables. This puts the data into tables serving a single purpose.
The process to redesign the table is database normalization.

There are three common forms of database normalization: 1st, 2nd, and 3rd normal form. They are also abbreviated as 1NF, 2NF, and 3NF respectively.
The forms are progressive, meaning that to qualify for 3rd normal form a table must first satisfy the rules for 2nd normal form, and 2nd normal form must adhere to those for 1st normal form.
First Normal Form – The information is stored in a relational table with each column containing atomic values. There are no repeating groups of columns.
Second Normal Form – The table is in first normal form and all the columns depend on the table’s primary key.
Third Normal Form – the table is in second normal form and all of its columns are not transitively dependent on the primary key