The Data Warehousing System
A data warehouse is a decision support database that is maintained separately from the organization‘s operational databases. Operational databases contain data pertaining to each transaction while data warehouses contain summary data such as totals, counts, maximums and minimums. The data stored in a data warehouse is optimized for querying and data analysis. Data warehousing systems deals with design, implementation, and operations of a data warehouse including data extraction, data cleansing, data transformation, and loading of data from different sources. The system also includes meta-data management, security management, backup and restore, and disaster recovery.