Different Stages of Data Warehousing

A 'data warehouse' is a repository of an organization's electronically stored data. Data warehouses are designed to facilitate reporting and analysis. There are various stages in data warehousing and . I found few articles very interesting that talks about the stages.

THE DATA WAREHOUSING STAGES 

The first stage of data warehousing is building a data mart.

A data mart is a subset of an organizational data store, usually oriented to a specific purpose or major data subject, that may be distributed to support business needs.Data marts are analytical data stores designed to focus on specific business functions for a specific community within an organization. Data marts are often derived from subsets of data in a data warehouse, though in the bottom-up data warehouse design methodology the data warehouse is created from the union of organizational data marts. 

Data mart is used for  Analytical processing. The results are attractive and the proof that analytical processing can be used effectively in the decision making process is verified by this step.

Soon what happens is the organization wants to have more analytical dataand data mart spurts up in every department.Soon the organization realizes that the numerous data mart are nothing but the  data warehouse itself.

APPLICATION DATA WAREHOUSE

Soon after this, application data warehouse appears .An application data warehouse is not the same thing as a data mart. The data inside the application data warehouse is integrated and granular. Data inside an application data warehouse is built with the next iteration of development in mind. Data is structured with the full knowledge that more data and different types of data are going to be added.

FUNCTIONAL DATA WAREHOUSE

This is also application data warehouse at the lowest level, but at the broad level , this encompasses many application in same functional area. 

PHASE 1 ENTERPRISE DATA WAREHOUSE

The Phase 1 enterprise data warehouse is a data warehouse for the entire enterprise. The enterprise data warehouse is built in phases. It is often difficult to tell a Phase 1 enterprise data warehouse from an application data warehouse, as they have many common characteristics.

PHASE N ENTERPRISE DATA WAREHOUSE

This is a result of many different development efforts, each of which adds to the enterprise data warehouse. The Phase N enterprise data warehouse is a large, detailed, multifaceted data warehouse.