A Data Warehouse is a repository for historical business data. A data warehouse is used to consolidate large amounts transaction and operational data into a form that can be queried for analysis. Typically the data in a data warehouse has been cleansed and normalized in a process known as ETL (extract, transform, and load). The data is them organized by specific dimensions and stored in a Data Cube. Dimensions include time (day, month, year), geographic locale (country, region, state, city), and product type.

As part of the Business Intelligence process, data warehousing falls between Online Transaction Processing (OLTP) and Online Analytical Processing (OLAP). Information from multiple Data Marts is consolidated during the ETL process, and then stored in a multidimensional data cube. Data Mining techniques are used to analyze the cube data and produce reports.

See Also:
Data Mart
Data Mining
Extract, Transform, and Load
Online Analytical Processing
Online Transaction Processing

Tags: data warehouse, Database