Databases & Data Storage
Data Warehouse
Definition
A data warehouse is a large, centralized repository of data that is collected from a variety of sources. It is designed specifically for fast querying and analysis, and often contains large amounts of historical data.
Why It Matters
Data warehouses are the foundation of business intelligence (BI). They provide a single source of truth for an organization's data, enabling analysts to run complex queries, generate reports, and gain insights into business trends.
Contextual Example
A retail company combines sales data from its stores, website, and mobile app into a central data warehouse. Analysts can then query this data to understand customer behavior, track sales performance, and identify popular products.
Common Misunderstandings
- A data warehouse is optimized for read-heavy analytical queries (OLAP), not for write-heavy transactional operations (OLTP).
- It is different from a data lake, which stores raw, unstructured data. Data in a warehouse is typically cleaned, transformed, and structured first (a process called ETL).