Data warehouse

Data Modeling Basics In Data Warehouse

Data modeling is a process of database table design.
There are two types of data models
1.E-R Modeling: is known as entity relationship modeling which is build based on normalization.
2.Dimensional Modeling: It is created in de-normalized form using dimension and fact tables.

Normalization
Normalization is a process of splitting the bigger tables into smaller tables. The objective of normalization is to minimize redundancy by not having  the same data stored in multiple tables.
De-normalization  
It is a process of combining multiple tables in to single tables. It creates a data redundancy. Redundency is a technique that involves duplicating  data in one or more tables to minimize of eliminate time consuming joins.

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