Apache TinkerPopAT
Apache TinkerPop•2y ago
qfel

Setting index in gremlin-python

I was trying to create vote graph from tutorial on loading data in gremlin-python and afaik you can't simply add index from non-JVM languages because for example there is no TinkerGraph that you could .open(). I don't know how better is performance when having index on 'userId' but my code simply takes too long go through queries from vote file.

I tried using client functionality
ws_url = 'ws://localhost:8182/gremlin'

# Create index on userId
client = Client(ws_url, 'g')
client.submit('graph = TinkerGraph.open()')
client.submit("graph.createIndex('userId', Vertex.class)")
client.close()

conn = DriverRemoteConnection(ws_url, 'g')
g = traversal().with_remote(conn)

to do it from string query and i'm not sure if with_remote(conn) uses previously assigned graph, let me know how to do it correctly. I'm not sure how to assign to 
g
 from client.submit(...).

Additionally: how does one speed up those queries, if setting index won't do it?
In my implementation
def idToNode(g: GraphTraversalSource, id: str):
    return g.V().has('user', 'userId', id) \
            .fold() \
            .coalesce(__.unfold(), 
                      __.add_v('user').property('userId', id)) \
            .next()

def loadVotes():
    with open("/tmp/wiki-Vote.txt", "r") as file:
        for _ in range(4):
            next(file)

        for line in file:
            ids = line.split('\t')
            from_node = idToNode(g, ids[0])
            to_node = idToNode(g, ids[1])
            g.add_e('votesFor').from_(from_node).to(to_node).iterate()

call to idToNode for each line takes too long.
Solution
if you simply edit that line of code to create your index and load your vote data, every time you start Gremlin Server it will have that all setup and ready to go.
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