Graph Database (Dgraph) for Persistence

[TigerWhiteDev]

Objective

Add plugin on Horizon for interact with dgraph databases

Justify and implement the chosen technical solution for persistence: Dgraph.

Why not relational or other NoSQL?

• Relational databases: not well-suited for deep hierarchies (queries become expensive with many joins).
• Document databases: require duplication/denormalization, leading to consistency issues.
• Key-value or column-oriented stores: good for simple analytics, but not suited for complex, dynamic relationships.

Why Dgraph?

• Performance and scalability: designed to distribute data and queries across multiple nodes.
• Natural modeling: hierarchies and dependencies are directly expressed as a graph.
• Flexibility: adding new relationship types does not require heavy refactoring.
• Powerful queries: fast hierarchical traversals (e.g., retrieve all descendants of an object).
• Consistency: ACID transactions, unlike some NoSQL solutions.

Concrete use cases

• Persisting player state (location, stats, active missions) so that a player can log out and reconnect seamlessly.
• Tracking containers such as cargo holds, storage crates, or loot chests, with all nested items stored and retrievable.
• Updating player or ship movements: only relative positions are recalculated, minimizing the amount of data updated in the graph.