Explain why large firms use data warehouses. 

What will be an ideal response?

Large firms maintain many databases, which might or might not be linked together into an overall structure. To provide rapid access to this information, companies use software packages that organize and store data in special configurations called data warehouses. A data warehouse is an integrated collection of data that can include seemingly unrelated information, no matter where it is stored in the company. Because it can link various information systems and databases, a data warehouse provides an enterprise-wide view to support management analysis and decision making. A data warehouse allows users to specify certain dimensions, or characteristics. By selecting values for each characteristic, a user can obtain multidimensional information from the stored data.