Data warehouse

Data warehouse is a collection of integrated data from a variety of sources, stored and maintained in a data structure that facilitates use and reporting. Data warehouses typically contain historical data derived from transaction data, such as sales and distribution systems. The data are transformed, cleansed and integrated into a single, centralized repository.

Data warehouses make data available to users for analysis and decision making. Data warehouse systems are intended to support business intelligence tasks, such as online analytical processing, data mining, and decision support query languages.

Data warehouses are used to combine data from disparate sources, and divide it into smaller chunks for easier accessibility and analysis. The data is stored in a form that is optimized for querying and reporting purposes. The data warehouse contains “cubes” that are analogous to multi-dimensional arrays, and can be queried with languages like SQL.

Data warehouses can be run on many different platforms, including traditional relational databases, distributed system such as Hadoop, and columnar databases such as Vertica. Careful planning is required to design a data warehouse as they are large, complex systems, and require a significant amount of time to develop.

A data warehouse is typically updated periodically with new data, as it is often used to track and analyze past events. Data warehouses can be used to improve organization performance, identify new markets or product opportunities, and explore customer behaviors.

Data warehouses are not limited to just businesses; they are also used by a wide range of organizations, including financial institutions, government organizations and healthcare organizations.