# RethinkDB — The Real-Time Document Database

> RethinkDB is an open-source document database that pushes query results to your application in real time. Build live dashboards and collaborative apps without polling.

## Install

Save in your project root:

# RethinkDB — The Real-Time Document Database

## Quick Use
```bash
docker run -d -p 8080:8080 -p 28015:28015 rethinkdb
# Open http://localhost:8080 for the admin UI
pip install rethinkdb
python -c "from rethinkdb import r; conn=r.connect(); r.db_create('test').run(conn)"
```

## Introduction
RethinkDB is a document database designed for the real-time web. Its killer feature is changefeeds — persistent queries that push updates to your app the instant data changes. Instead of polling, your application subscribes to a query and receives a continuous stream of results.

## What RethinkDB Does
- Stores JSON documents with a flexible schema like MongoDB
- Pushes live query results via changefeeds without polling
- Scales horizontally with automatic sharding and replication
- Provides a rich query language (ReQL) with joins, subqueries, and map-reduce
- Includes a built-in web admin UI for cluster management

## Architecture Overview
RethinkDB uses a shared-nothing distributed architecture. Data is split into shards distributed across a cluster, with configurable replicas for fault tolerance. The storage engine is based on a log-structured merge tree. Changefeeds are implemented at the query level — any ReQL query can be turned into a live feed, and the server efficiently pushes diffs when underlying data changes.

## Self-Hosting & Configuration
- Deploy via Docker, official packages for Ubuntu/Debian/CentOS, or compile from source
- Configure cluster joins with --join host:port for multi-node setups
- Set --cache-size to control memory usage for the buffer pool
- Enable TLS with --tls-cert and --tls-key for encrypted client connections
- Use the web UI at port 8080 to manage tables, shards, and replicas visually

## Key Features
- Changefeeds turn any query into a real-time push stream
- ReQL query language chainable in Python, JavaScript, Ruby, and Java
- Automatic failover with configurable replication per table
- Geospatial indexes for location-based queries
- Atomic document updates with conflict resolution

## Comparison with Similar Tools
- **MongoDB** — requires change streams (oplog-based); RethinkDB changefeeds work on arbitrary queries
- **Firebase Realtime DB** — proprietary, limited query power; RethinkDB is open source with full joins
- **CouchDB** — focuses on sync and replication; RethinkDB optimizes for low-latency push queries
- **PostgreSQL LISTEN/NOTIFY** — row-level signals only; RethinkDB streams full query results
- **Redis Pub/Sub** — ephemeral messaging; RethinkDB persists data and pushes computed query diffs

## FAQ
**Q: Is RethinkDB still maintained after the company shut down?**
A: Yes. The Linux Foundation and the CNCF community took over the project. Active development continues under the rethinkdb GitHub organization.

**Q: Can RethinkDB replace MongoDB?**
A: For apps that benefit from real-time push, yes. For pure write-heavy CRUD without live needs, MongoDB may have broader ecosystem tooling.

**Q: How does RethinkDB handle consistency?**
A: It uses immediate consistency by default for single-document writes and supports configurable read modes (single, majority, outdated).

**Q: What clients are available?**
A: Official drivers exist for Python, JavaScript/Node.js, Ruby, and Java. Community drivers cover Go, C#, Rust, and more.

## Sources
- https://github.com/rethinkdb/rethinkdb
- https://rethinkdb.com/docs

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Source: https://tokrepo.com/en/workflows/147bedb5-399f-11f1-9bc6-00163e2b0d79
Author: AI Open Source