Abstract
A Data Warehouse is a collection of technologies aimed to enable the decision maker to make faster and better decisions. The data warehousing has some main problems need to be solved to increase the quality of the data warehouse and its data. One of the popular problems of the data warehousing is Data Integration, which is the making of query across multiple autonomous and heterogeneous data sources with respect of quality factors. There are many integration systems (Software) each of which has its own features and benefits which will be stated in details in this research, then the researcher choose one of them to apply a case study.