RethinkDB is an open-source, scalable database specifically designed for the realtime web, allowing developers to build reactive applications with significantly less engineering effort.

The principal functionalities of this tool include:

1. Realtime Data Pushing

• Active Updates: Unlike traditional databases that require apps to poll for data, RethinkDB pushes JSON updates to applications in realtime.

• Broad Use Cases: This functionality is ideal for building multiplayer games, reactive web and mobile apps (like collaborative editors), realtime marketplaces, and streaming analytics dashboards.

• IoT Integration: It simplifies IoT infrastructures by streaming data between connected devices and triggering actions in millions of devices within milliseconds.

2. Robust and Modern Architecture

• High Performance: The database features a state-of-the-art storage engine, a highly optimized buffer cache, and a modern distributed architecture.

• Complex Query Support: It supports advanced database features including table joins, location-aware (geospatial) applications, and time-series data storage.

• Analytics Tools: Developers can perform deep analytics using aggregation and map/reduce functions, supported by flexible indexing to speed up performance.

3. Scalability and Cluster Management

• One-Click Scaling: Users can shard and replicate their data across a cluster in seconds using an intuitive web-based UI.

• Precise Control: For advanced management, a simple API provides granular control over the cluster.

• Live Monitoring: The system includes built-in tools to monitor production clusters with live statistics and complete visibility into running jobs.

4. Developer Experience

• Multi-Language Support: It allows querying JSON documents using Python, Ruby, Node.js, and dozens of other popular programming languages.

• Flexible Stack: It pairs seamlessly with modern web frameworks and realtime technologies like Socket.io or SignalR.

• Easy Deployment: RethinkDB can be installed in seconds on Linux, macOS, or DigitalOcean.