When would you choose a graph database over a relational database?

Choose a graph database when: 1) Relationships are the primary concern — not just data, but HOW data connects. 2) Variable depth traversals are needed — 'friends of friends of friends' at any depth. 3) Relationship properties matter — when/how the connection was made. 4) Performance degrades with JOINs — relational JOINs are O(n×m) per hop; graph traversal is O(1) per hop. Use cases: social networ