Data warehouse

Data warehouse is subjected oriented, integrated, time variant and non-volatile collection of data which supports decision making process of any organization. The data warehouse is oriented around the major subjects of the organization. The data warehouse focuses on zone, exporter, product and activity and thus data modeling and database design is carried out. The data in the data warehouse is integrated and also accurate for some moment of time. On the contrary, in the operational environment, the data is accurate only during accessing. Therefore, for a long term perspective, data warehouse gets significance. Time horizon for data warehouse is 5-10 years which is very very long compared to 60-90 days time horizon of operational environment. The major operations in a data warehouse are initial loading of data and access of data.