Data Warehousing
Practice this topic in a realistic system design interview
Production databases are built for small, fast reads and writes: place an order, update a status, look up a customer. Business questions look very different. They scan months or years of history, group it in different ways, and often need data from several systems at once. Running those queries on the production database slows down the application, and the data they need often isn't there in the first place.
A data warehouse is a separate database built for this kind of analysis.
In this chapter, we will look at what a data warehouse is, why analytical workloads need a different kind of database, how warehouses process large amounts of data efficiently, and how that data is organized for analysis.