Amazon SimpleDB vs Firebase Realtime Database: What are the differences?

Amazon SimpleDB: Highly available and flexible non-relational data store. Developers simply store and query data items via web services requests and Amazon SimpleDB does the rest. Behind the scenes, Amazon SimpleDB creates and manages multiple geographically distributed replicas of your data automatically to enable high availability and data durability. Amazon SimpleDB provides a simple web services interface to create and store multiple data sets, query your data easily, and return the results. Your data is automatically indexed, making it easy to quickly find the information that you need. There is no need to pre-define a schema or change a schema if new data is added later. And scale-out is as simple as creating new domains, rather than building out new servers; Firebase Realtime Database: Store and sync data in real time. It is a cloud-hosted NoSQL database that lets you store and sync data between your users in realtime. Data is synced across all clients in realtime, and remains available when your app goes offline.

Amazon SimpleDB and Firebase Realtime Database belong to "NoSQL Database as a Service" category of the tech stack.

Some of the features offered by Amazon SimpleDB are:

• Amazon SimpleDB automatically manages infrastructure provisioning, hardware and software maintenance, replication and indexing of data items, and performance tuning.
• Amazon SimpleDB automatically creates multiple geographically distributed copies of each data item you store.
• You can also choose between consistent or eventually consistent read requests, gaining the flexibility to match read performance (latency and throughput) and consistency requirements to the demands of your application, or even disparate parts within your application.

On the other hand, Firebase Realtime Database provides the following key features:

• Real time syncing for JSON data
• Collaborate across devices with ease
• Build serverless apps