Relational databases and data warehouse

Relational databases are designed for on-line transactional processing (OLTP) and is usually used to track real-time information furthermore permit us to modify data (add, change or delete data). (1)

Whereas data warehouse is transforming and loading data from source systems into the data warehouse, which means it is read only database, include years of summarized data, used meanly for reporting purposes and to help in the decision making.

Therefore Data Warehouse is (2)
1.Time Referenced (hold years of data)
2.Subject-Oriented (group data by subject rather than by activity)
3.Non-volatile (read only)
4. Integrated

Using Data Warehouse During Times of Change.
If any organization wants to have comparable history throughout a long period then a data warehouse will be best answer to create comparable data to current performance. Because data warehouse can store historical data which will be very useful when it compares with the current data. (3)

Another use for data warehouse is analyze data to spot trends

Data warehouse could help any business analyzes data to spot trends, uncover problems or for example identifies which customers are about to stop their contract, and then decide in what type of action the organization has to take to stop these customers from leaving, to be able to do all the above the organization needs a data warehouse which collect data from the operational databases, for instance, the sales databases, the customer service databases, the order management databases and so on.

Links accessed May 4, 2006