How to: Database Federation
Federation (or functional partitioning) splits up databases by function. The federation architecture makes several distinct physical databases appear as one logical database to end-users.

All of the components in a federation are tied together by one or more federal schemas that express the commonality of data throughout the federation. These federated schemas are used to specify the information that can be shared by the federation components and to provide a common basis for communication among them.

![database-federation](https://raw.githubusercontent.com/karanpratapsingh/portfolio/master/public/static/courses/system-design/chapter-II/database-federation/database-federation.png)

Federation also provides a cohesive, unified view of data derived from multiple sources. The data sources for federated systems can include databases and various other forms of structured and unstructured data.