[SOLVED] How to delete graph in Titan with Cassandra storage backend?

How to delete graph in Titan with Cassandra storage backend?

I use Titan 0.4.0 All, running Rexster in shared VM mode on Ubuntu 12.04.

How could I properly delete a graph in Titan which is using the Cassandra storage backend?

I have tried the TitanCleanup.clear(graph), but it does not delete everything. The indices are still there. My real issue is that I have an index which I don't want (it crashes every query), however as I understand Titan's documentation it is impossible to remove an index once it is created.

Solution

You can clear all the edges/vertices with:

g.V.remove()

but as you have found that won't clear the types/indices previously created. The most cleanly option would be to just delete the Cassandra data directory.

If you are executing the delete via a unit test you might try to do this as part of your test setup:

this.config = new BaseConfiguration(){{
    addProperty("storage.backend", "berkeleyje")
    addProperty("storage.directory", "/tmp/titan-schema-test")
}}
GraphDatabaseConfiguration graphconfig = new GraphDatabaseConfiguration(config)
graphconfig.getBackend().clearStorage()
g = (StandardTitanGraph) TitanFactory.open(config)

Be sure to call g.shutdown() in your test teardown method.