Data warehouse is a system used for reporting and data analysis and is considered a core component of business intelligence. It combines information collected from multiple sources into one comprehensive database. In another word, the main function of Data Warehouse is to extract information from various SQL-based sources and create analytic reports considering all gathered data.

There are three different types of Data Warehouse: Enterprise Data Warehouse, Operational Data Store, and Data Mart.

1. Enterprise Data Warehouse is a centralized warehouse, which provides decision support service across the enterprise. It offers a unified approach to organizing and representing data. It also provides the ability to classify data according to the subject and give access according to those divisions.
2. Operational Data Store is data store required when Data Warehouse does not support organizations reporting needs. In Operational Data Store, Data Warehouse is refreshed in real time. Therefore, it is widely preferred for routine activities like storing records of the Employees.
3. Data Mart is a subset of the data warehouse. It is specially designed for specific segments like sales, finance. In an independent data mart, data can be collected directly from sources.

Here are some great reasons to invest in a data warehouse or other form of centralized data system that analysts and products can utilize.

• Data warehouse enhances business intelligence
• High return on investment
• Time efficient
• Maintain data history
• Integrate data from multiple source systems, enabling a central view
• Improve data quality, by providing codes and descriptions, or even fixing bad data
• Present the organization’s information consistently
• Provide a single common data model for all data source
• Restructure the data to makes sense the users
• Restructure the data to delivers excellent query performance
• Add value to operational business applications
• Reduces reporting cost
• Reduce data consolidation and integration cost
• Increase efficiency and decision-making capabilities

Data warehouses provide a lot of advantages. They allow companies to quickly access and analyze their data effectively from some sources all in one place. It creates accuracy, dependably and democratizing data so that more than just the purely technical employees can access it. Data Warehouse is used in diverse industries like Airline, Banking, Healthcare, Insurance, Retail etc.