Data Modelling

Data modeling

• Is a conceptual representation of data structure.
• It is very powerful of expressing & communicating the business requirement.
• Model represent nature of data & Business rule.
• Data model helps functional & Technical team in designing database.
• Data modeler responsible for designing the data model & they communicate with functional team to get requirement and technical team to implement the database.

Importance of Data Model

• Make sure that all data object provided by functional team are completely & accurately represented.
• Data model very used full to technical team to built physical database.
• Data model will be used to define significance of business, Relational tables, primary & foreign key & stored procedure.
• Make sure that all data object provided by functional team are completely & accurately represented.  
• Data model very used full to technical team to built physical database. Data model will be used to define significance of business, Relational tables, primary & foreign key & stored procedure.

Step to Create Data Model                                                                         

1. Get Business Requirement   
2. Create High level Conceptual Data Model
3. Create Logical Data Model.
4. Select target database where data modelling tool create the physical schema.
5. Create Entities and attributes.
6. Assign Data type to Attributes.
7. Create Primary & Unique to attributes.
8. Create indexes on a attributes.
9. Create foreign key relationship between attributes.
10. Create physical data model.
11. Create SQL script from physical data model & forward toDBA.
12. Maintain logical & physical Data model.

Data Modelling Development Life Cycle

First Phase : Gathering business requirements

Data Modeller have to interact with business analysts to get the functional requirement and with End users to find out the reporting needs.

Second Phase: Conceptual Data Modelling

This data model includes all entities, relationship and it will not contain much details about attributes. This is initial planning phase.

Third Phase: Logical Data Model

A Logical Model is the version of the model that represent all of the business requirements of an organization.

Fourth Phase: Physical Data Model.

This is a complete model that include all required tables, column, relationship, database properties for the physical implementation of data Database.