Data Warehouse

A data warehouse is a central database optimized for analysis that keeps cleaned data from multiple sources together for heavy analytical queries.

A data warehouse differs from an operational database: an operational database is built for fast writing of live transactions, a warehouse for reading and aggregating large volumes of historical data. Its value shows when you want to place several systems' data (web, sales, CRM) together and ask questions no single-purpose tool can answer. But a warehouse is not a finished product for the user, it is infrastructure; having one means the team must take on modeling, quality and query-writing itself. For most businesses a tool's ready reports suffice, and a warehouse only makes sense once blended, custom analysis has become a continuous need and a dedicated data team exists.