Graph Databases: Neo4j and the Power of Relationships

Relational databases are great at storing rows. They are bad at traversing deep relationships.

Query: "Find friends of friends of friends of Alice." SQL: 3 nested JOINs. Slow. Graph DB: A simple traversal. Instant.

Nodes and Relationships

In Neo4j, data is stored as Nodes (Entities) and Relationships (Lines connecting them).

MATCH (alice:Person {name: 'Alice'})-[:FRIEND]->(bob)-[:FRIEND]->(fof)
RETURN fof

Use Cases

1. Social Networks: Who follows whom?
2. Recommendation Engines: "People who bought X also bought Y".
3. Fraud Detection: Link analysis to find ring of fraudsters.

If your data is more about the connections than the entities themselves, use a Graph Database.