Importance of data warehousing

1.      Congregate data from multiple sources into a single database so a single query engine can be used to present data.

2.      Mitigate the problem of database isolation level lock contention in transaction processing systems caused by attempts to run large, long running, analysis queries in transaction processing databases.

1.      Maintain data history, even if the source transaction systems do not.

2.      Improve data quality, by providing consistent codes and descriptions, flagging or even fixing bad data.

3.      Present the organization's information consistently

4.      Provide a single common data model for all data of interest regardless of the data's source.

5.      Restructure the data so that it makes sense to the business users.

6.      Restructure the data so that it delivers excellent query performance, even for complex analytic queries, without impacting the operational systems.

7.      Add value to operational business applications, notably customer relationship management (CRM) systems

8.      Integrate data from multiple source systems, enabling a central view across the enterprise. This benefit is always valuable, but particularly so when the organization has grown by merger.