Vercel and Netlify provide developers with full-stack serverless applications through features like serverless edge functions, CDN, build tools, analytics, etc. Both platforms allow for the use of various databases to store data, including MySQL-compatible serverless databases like PlanetScale, NoSQL databases like MongoDB (MongoDB Atlas) and document-relational databases like Fauna. When choosing a database, factors such as scalability, performance, latency, consistency, and ease of use come into play, particularly with edge architectures that require distributed data storage to reduce latency. While PlanetScale offers flexibility and global distribution, its limitations in sharding and schema migration may impact performance. MongoDB Atlas provides managed instances of the Mongo database, but lacks transactional support and has limited functionality compared to Fauna, which combines the best of SQL and NoSQL with flexible document-relational data modeling, strong consistency, serverless architecture, and native integration with Vercel and Netlify. Ultimately, developers should choose a database that aligns with their application's requirements and follows the philosophy of serverless edge architecture.