Databases come in two forms in App Platform: dev databases, which are not intended for production use, and managed databases, which are instances of a DigitalOcean managed database that you have created outside of App Platform and would like to use in production.
Dev databases only come in one size and will not scale well to handle traffic for your app. Additionally, your dev database permissions will not allow you to create databases; instead you will need to use the default database.
Managed databases have features like standby nodes, upscaling, and read-only nodes that add extra processing and throughput capacity for your database solution, and multiple trusted sources internal and external to DigitalOcean services. To use a managed database, create one in your DigitalOcean account. From the Create menu in the top right of the control panel, click Databases. The database you create appears in the Database Clusters list when you add a database component in App Platform.