A data warehouse is a centralized system designed to store large volumes of structured, historical data from multiple operational sources for reporting and analysis. Data is typically extracted from systems such as applications, databases, and business platforms, then cleaned and transformed before being loaded into the warehouse. Unlike transactional databases, warehouses are optimized for querying and analyzing data rather than handling day-to-day transactions.
For example, a retailer can combine sales, customer, inventory, and marketing data in a warehouse to compare performance across regions and time periods. Analysts and business intelligence tools can then query this consolidated information without placing heavy workloads on operational systems. Related concepts include data lakes, ETL, ELT, business intelligence, data marts, and dimensional modeling.
