Data modeling

Data Modeling:

Model: Model is business representation of

information in one or more data sources

OLTP                                   DWH

 Model         Model                Model

E-R Model   (modify wih ETL)      Dimensional model

(Design based on             (Design based on facts and Measures)

Entities&Relationships)

 

Dimensional Modeling: Is a design methodology for designing a DWH

It consists of following 3phases to design the

Database

1)Conceptual Modeling:

•         Understanding the requirements

•         Identifying the dimensions and Facts

2)Logical Modeling:

•         Design the dimensions and facts

•         Identifying the relationships between dimensions and facts

3)Physical Modeling:

•         Execute the structures in the database to physically store the data

•         A schema consist of user defined objects like tables, views, synonyms etc;

 

 

Data Modeling is a process of designing

database with its following types of shema

•       Star schema

•       Snowflake schema