CODEWITHSUNDEEP
neo4j
Todd Michaud
Todd Michaud

Reputation: 21

Has anyone used Neo4j node IDs as foreign keys to other databases for large property sets?

I am building a large graph database that has a significant set of meta data about each node (thousands of properties per node). I am currently going through the process of determining which meta data should be a node within Neo4j, which should become a property of the Node and which should be housed in a separate database.

My thinking is to use the meta data in 3 ways:
1 - If the property is shared between many nodes, to make that property it's own node and create an edge to that property.

2 - If the property is important to traversing the graph, but not "highly" shared, to add that as a node property. (Which could also be indexed within Neo4j if needed)

3 = If the meta data is strictly describing that node, to have that stored in a separate NoSQL database, with the Neo4J Node ID becoming the foreign key to the other database.

While it seems like the most efficient use of using the graph database, it seems like a pain to have the different property types and having to determine which type of property it is before using it. (Likely a property lookup key-value store) It would also likely mean that I would need an easy way to promote a property from 3 to 2 to 1 for instances when a property becomes highly shared, or needed for efficient traversal.

Has anyone taken this approach? Any thoughts to share, or things to avoid?

Upvotes: 2

Views: 1548

Answers (1)

Stefan Armbruster
Stefan Armbruster

Reputation: 39915

Do never ever store a Neo4j node id in an external system. The node id is basically a offset in the respective store file. If you delete a node its id might be reused when new nodes are created.

The right approach is to have a "good" identifier (e.g. uuid) as a node property and put that into Neo4j's index. That uuid is then save to be stored in third party systems.

Some time ago I've created a unmanaged extension that adds a uuid to each new node and prevent manual changes to these uuids: https://github.com/sarmbruster/neo4j-uuid.

Update (2013-08-21)

I've blogged about UUIDs with Neo4j.

Upvotes: 6

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