Federated Database
A federated database is a system that integrates multiple autonomous databases into a single virtual database, allowing users to query and access data across disparate sources as if they were a unified system. It uses a middleware layer to manage data distribution, schema mapping, and query processing without physically consolidating the data. This approach enables organizations to leverage existing databases while providing a cohesive view of distributed information.
Developers should learn about federated databases when working in environments with multiple, heterogeneous data sources (e.g., legacy systems, cloud databases, or departmental silos) that need to be accessed collectively for analytics, reporting, or application integration. It is particularly useful in scenarios where data cannot be centralized due to regulatory constraints, performance issues, or the high cost of migration, as it allows for real-time data access without disrupting existing systems.