ArangoDB

Slack:

ArangoDB is a scalable open-source multi-model database natively supporting graph, document and search. All supported data models & access patterns can be combined in queries allowing for maximal flexibility. ArangoDB runs on prem, in the cloud – anywhere.

ArangoDB Cloud Service

Oasis is the simplest way to run ArangoDB. Users can make deployments on all major cloud providers in many regions. Test ArangoDBs Cloud Service Oasis for free.

Getting Started

Free Udemy Course
Training Center
Documentation

For the impatient:

Start the ArangoDB Docker container

docker run -e ARANGO_ROOT_PASSWORD=test123 -p 8529:8529 -d arangodb/arangodb

Alternatively, download and install ArangoDB. Start the server arangod if the installer did not do it for you.
Point your browser to http://127.0.0.1:8529/

Key Features in ArangoDB

Multi-Model: Documents, graphs and key-value pairs — model your data as you see fit for your application.
Joins: Conveniently join what belongs together for flexible ad-hoc querying, less data redundancy.
Transactions: Easy application development keeping your data consistent and safe. No hassle in your client.

Here is an AQL query that makes use of all those features:

Joins and transactions are key features for flexible, secure data designs, widely used in relational databases but lacking in many NoSQL products. However, there is no need to forgo them in ArangoDB. You decide how and when to use joins and strong consistency guarantees, without sacrificing performance and scalability.

Furthermore, ArangoDB offers a JavaScript framework called Foxx that is executed in the database server with direct access to the data. Build your own data-centric microservices with a few lines of code. By extending the HTTP API with user code written in JavaScript, ArangoDB can be turned into a strict schema-enforcing persistence engine.

Other features of ArangoDB include:

Use a data-centric microservices approach with ArangoDB Foxx and fuse your application-logic and database together for maximal throughput
JavaScript for all: no language zoo, you can use one language from your browser to your back-end
Flexible data modeling: model your data as combination of key-value pairs, documents or graphs - perfect for social relations
Different storage engines: ArangoDB provides a storage engine for mostly in-memory operations and an alternative storage engine based on RocksDB which handle datasets that are much bigger than RAM.
Powerful query language (AQL) to retrieve and modify data
Transactions: run queries on multiple documents or collections with optional transactional consistency and isolation
Replication and Sharding: set up the database in a master-slave configuration or spread bigger datasets across multiple servers
Configurable durability: let the application decide if it needs more durability or more performance
Schema-free schemata let you combine the space efficiency of MySQL with the performance power of NoSQL
index support: exploit the perfect index types for your different use cases, including document queries, graph queries, geo location queries, and fulltext searches
ArangoDB is multi-threaded - exploit the power of all your cores
Easy to use web interface and command-line client tools for interaction with the server
It is open source (Apache License 2.0)