UPSERTing with TitanDB

Question

I\'m having my first steps as a TitanDB user. That being, I\'d like to know how to make an upsert / conditionally insert a vertex inside a TitanTransaction (in the

Answer 1

Roughly speaking, every Cassandra insert is an "upsert". If you look at the Titan representation of vertices and edges in a Cassandra-like model, you'll find vertices and edges each get their own rows. This means a blind write of an edge will have the given behavior you're looking for: what you write is what will win. Doing this with a vertex isn't supported directly by Titan.

But I don't think this is what you're looking for. If you're looking to enforce uniqueness, why not use the unique() modifier on a Titan composite index? (From the documentation):

mgmt.buildIndex('byNameUnique', Vertex.class).addKey(name).unique().buildCompositeIndex()

With a Cassandra storage backend, you need to enable consistency locking. As with any database, managing the overhead of uniqueness comes at a cost which you need to consider when writing your data. This way if you insert a vertex which violates your uniqueness requirement, the transaction will fail.