Datawarehouse Models

Data Warehouse Models From the perspective of data warehouse architecture we have the following data warehouse models:
1.Virtual Warehouse
2 Data mart
3 Enterprise Warehouse

VIRTUAL WAREHOUSE

• The view over a operational data warehouse is known as virtual warehouse. It is easy to built the virtual warehouse.
•  Building the virtual warehouse requires excess capacity on operational database servers. 

DATA MART

• Data mart contains the subset of organisation-wide data.
•  This subset of data is valuable to specific group of an organisation. 

Note: in other words we can say that data mart contains only that data which is specific to a particular group. For example the marketing data mart may contain only data related to item, customers and sales. The data mart are confined to subjects.


Points to remember about data marts

• Window based or Unix/Linux based servers are used to implement data marts. 
• They are implemented on low cost server.
•  The implementation cycle of data mart is measured in short period of time i.e. in weeks rather than months or years. 
• The life cycle of a data mart may be complex in long run if it's planning and design is not organisation-wide. Data marts are small in size.
•  Data mart is customized by department. The source of data mart is departmentally structured data warehouse. Data mart is flexible.

ENTERPRISE WAREHOUSE

• The enterprise warehouse collects all the information all the subjects spanning the entire organization 
• This provides us the enterprise-wide data integration.
• This provides us the enterprise-wide data integration. 
• The data is integrated from operational systems and external information providers. 
• This information can vary from a few gigabytes to hundreds of gigabytes, terabytes or beyond.