Difference between operational systems and data warehouse

Operational systems maintain records of daily business transactions whereas a Data Warehouse is a special database that serves as the integrated repository of company data, for reporting and decision support purpose. In other words operational systems are where the data is put in, and the data warehouse is where we get the data out.

In an operational system users takes orders, sign up new customers, and log complaints. They almost always deal with one record at a time in an operational system. They repeatedly perform the same operational tasks over and over. On the other hand, the users of a data warehouse watch the wheels of the organization turn. They count the new orders and compare them with last week's orders and ask why the new customers signed up and what the customers complained about. Users of a data warehouse almost never deal with one row at a time.

Typical relational databases are designed for on-line transactional processing (OLTP) and do not meet the requirements for effective on-line analytical processing (OLAP). As a result, data warehouses are designed differently than traditional relational databases.