arangodb

ArangoDB

ArangoDB is a native multi-model database. It allows you to store data as Key/Values, JSON Documents, and Graphs, and query them all with a single language (AQL).

When to Use

• Multi-Model Data Architectures: Unifying document (JSON), graph, and key-value models into a single query engine with ACID transactions.
• Complex Graph Traversals: Executing high-performance depth-first and breadth-first traversals with edge attributes in AQL.
• Unified Knowledge Graphs: Storing entity metadata as rich documents while querying interconnected relationships as graphs.
• Search & Full-Text Integration: Leveraging ArangoSearch for integrated full-text indexing, BM25 scoring, and geo-spatial queries.

Quick Start

// AQL (ArangoDB Query Language) - SQL-like
FOR u IN users
  FILTER u.active == true
  FOR order IN OUTBOUND u orders
    RETURN { user: u.name, order: order.product }

Core Concepts

Multi-Model Document & Edge Collections

Documents store unstructured JSON entities; Edge collections define directed connections between documents using _from and _to attributes:

// Vertex Document (users/alice)
{ "_key": "alice", "name": "Alice Mercer", "role": "Lead Architect" }

// Edge Document (knows/edge_1)
{ "_from": "users/alice", "_to": "users/bob", "relationship": "mentor", "since": 2024 }

ArangoDB Query Language (AQL) Graph Traversal

Traverses interconnected relationship graphs up to N hops:

// 1 to 3 hops outward traversal from Alice
FOR v, e, p IN 1..3 OUTBOUND 'users/alice' GRAPH 'socialGraph'
  FILTER e.relationship == 'mentor'
  RETURN {
    colleague: v.name,
    distance: LENGTH(p.edges),
    path: p.vertices[*].name
  }

Distributed Cluster Sharding (OneShard & SmartGraphs)

Ensures interconnected graph vertices and edges are colocated on identical physical DB servers to eliminate network hop penalties:

// Creates a SmartGraph partitioned by customer tenant ID
const graph = db._createSmartGraph(
  "tenantSocialGraph",
  [{ collection: "members", from: ["users"], to: ["users"] }],
  { smartGraphAttribute: "tenantId" },
);