Chapter 3. Architecture of a Data Warehouse
Data warehouses have evolved because, in order for businesses to remain competitive in the marketplace, they need access to a wealth of information to help them make the right business decisions. To assist with those decisions, data may go back for many years and could entail keeping the details of every item that a business ever sold. Performance optimizations for update-centric OLTP systems are well understood; however, data warehouses, being query-centric, have vastly different requirements, and a single business intelligence query may need to retrieve and aggregate many records from the warehouse.
In order to understand how the database can efficiently access this large amount of data, ...