DB2 Data Warehouse Concepts

Your organization may contain data in a variety of logical and physical DB2 servers. Each business unit may have their own database(s) containing vital information such as sales, inventory, and other forms of operational data. The largest business units may use DB2 for z-Series as their backend database server, while medium-sized units employ DB2 for AIX or DB2 for i-Series. Furthermore, if your organization employs decentralized or siloed information management, similar operational data for different business units may be stored in tables with different names and formats. This is also common when an organization grows by acquiring other companies, thereby inheriting new data architectures along the way.

In order to effectively manage your organization, business analysis on operational data across your enterprise is critical. What if you lost millions in sales because you had ten global sales offices selling widgets, each with its own sales database, all sharing the same inventory database. Suddenly everyone in North America starts buying widgets and you run out of inventory and production cannot supply the demand for all the new orders.

It may not be possible to have business analysts monitoring several database servers, each requiring a considerable level of expertise to access, or which are unavailable for performing business analysis because of the load generated by daily transaction processing. A data warehouse can offer a solution.

A data warehouse contains stores of informational data, taken primarily from operational data sources. Informational data is not used for analysis rather than for transactional or operational processing. There are three steps required to create a data warehouse.

• Extraction of data from operational or other informational data sources.

• Transformation of data into the data structures defined by the data warehouse.

• Loading data into the data warehouse.

The DB2 Warehouse Manager toolkit provides this functionality. When initializing the data warehouse, DB2 Data Warehouse Center also creates a control database. This is used to store information such as the permissions required to access data from various data sources.