Data warehouses

A data warehouse is a large, centralized repository of data that is used for storing and analyzing data from multiple sources. It is designed to support business intelligence (BI) activities, such as reporting, data mining, and online analytical processing (OLAP). In this overview, we will discuss the technical aspects of data warehouses, including their architecture, data modeling, and integration.

Architecture

The architecture of a data warehouse can be divided into three layers: the data source layer, the data storage layer, and the data access layer.

The data source layer consists of all the systems that provide data to the data warehouse. These systems can include transactional databases, operational data stores, and external data sources. Data from these sources is extracted, transformed, and loaded (ETL) into the data warehouse.

The data storage layer is where data is stored in a way that is optimized for reporting and analysis. The data in a data...