RethinkDB vs MongoDB

RethinkDB and MongoDB are both document databases, but RethinkDB was uniquely designed for real-time push queries. RethinkDB's original company shut down in 2016, and it is now a Linux Foundation project with a smaller community.

RethinkDB's Innovation: Changefeeds

RethinkDB's standout feature is changefeeds. You can attach a changefeed to any query, and the database will push results to your application in real-time whenever the underlying data changes. This inverts the traditional polling model — instead of asking "what changed?", the database tells you.

For example, r.table('players').orderBy('score').limit(10).changes() pushes the top 10 leaderboard to your app in real-time as scores change. This is fundamentally different from MongoDB's Change Streams, which watch for document-level changes rather than query-level result changes.

MongoDB's Practical Advantages

MongoDB has the practical advantages of an actively developed product: multi-document ACID transactions, mature sharding, a managed cloud service (Atlas), a massive ecosystem of drivers and tools, and a large community.

Learn about real-time database patterns in system design concepts and interview questions.

Current Status

RethinkDB is maintained by the community under the Linux Foundation but receives limited development compared to its peak. MongoDB continues rapid development with Atlas Search, Vector Search, Device Sync, and more. For production workloads, MongoDB is the safer choice.

The Legacy of RethinkDB

RethinkDB's changefeed concept influenced many subsequent systems. Firebase, Supabase real-time, and Hasura subscriptions all echo RethinkDB's vision of the database pushing data to clients.

The Bottom Line

Choose RethinkDB if its changefeed model uniquely fits your real-time application architecture and you are comfortable with community-maintained software. Choose MongoDB for production workloads where active development, managed services, and ecosystem breadth matter. See system design guides.