Marko and Michael, Thanks a lot. I will try it as you described.
one question for Michael, in this case u just created ur nodes without setting
any properties. I think setting properties will take some time, istn't it?
greetings,
Lama
> From: michael.hun...@neotechnology.com
> Date: Wed, 11 May 2011 00:08:23 +0200
> To: user@lists.neo4j.org
> Subject: Re: [Neo4j] million of nodes, max degree of a node
>
> And yes, you can easily build your db with millions of nodes that way.
>
> Just try it for yourself.
>
> Important is to choose a batch size for transactions that is not too small.
> E.g. commit each 10000 nodes.
> To speed it up further you may disable caching for only the import.
>
> Code sample below, it inserts 1 mio node in 3 secs on my mac.
>
> Cheers
>
> Michael
>
>
> package org.neo4j.load;
>
> import org.apache.commons.io.FileUtils;
> import org.neo4j.graphdb.GraphDatabaseService;
> import org.neo4j.graphdb.Transaction;
> import org.neo4j.kernel.AbstractGraphDatabase;
> import org.neo4j.kernel.EmbeddedGraphDatabase;
>
> import java.io.File;
> import java.io.IOException;
> import java.util.HashMap;
> import java.util.Map;
>
> public class Loader {
>
> public static final int COUNT = 10000;
> public static final int BATCHES = 100;
>
>
> public static void main(String[] args) throws IOException {
> FileUtils.deleteDirectory(new File("target/test"));
> Map<String, String> config=new HashMap<String, String>();
> config.put("cache_type","weak"); // or "none"
> GraphDatabaseService gds = new EmbeddedGraphDatabase("target/test", config);
> long time = System.currentTimeMillis();
> for (int i=0;i< BATCHES;i++) {
> createNodes(gds, COUNT);
> }
> time = System.currentTimeMillis() - time;
> System.out.println("time for "+BATCHES*COUNT+" = " + time/1000);
> }
>
> private static void createNodes(GraphDatabaseService gds, int count) {
> Transaction tx = gds.beginTx();
> try {
> for (int i=0;i< count;i++) {
> gds.createNode();
> }
> tx.success();
> } finally {
> tx.finish();
> }
> System.out.print(".");
> }
> }
> Am 10.05.2011 um 23:36 schrieb Marko Rodriguez:
>
> > Hey,
> >
> >> One more thing, is there any algorithm which shows the node that has the
> >> maximum of edges ??
> >
> >
> > In Java, do:
> >
> > Map m = new HashMap();
> > for(Node node : graph.getAllNodes()) {
> > for(Relationship rel : node.getRelationships()) {
> > c++;
> > }
> > m.put(node, c);
> > }
> >
> > ----------------
> >
> > In Gremlin (http://gremlin.tinkerpop.com), do:
> > m = [:]; g.V.sideEffect{m[it] = it.both.count()}
> >
> > ----------------
> >
> > Both yield a map of the degree of each node. You can then sort if you wish
> > or just alter the code to keep a reference to the highest node degree seen
> > so far. The latter being less memory intensive.
> >
> > Hope that helps,
> > Marko.
> >
> > http://markorodriguez.com
> >
> >
> >
> > _______________________________________________
> > Neo4j mailing list
> > User@lists.neo4j.org
> > https://lists.neo4j.org/mailman/listinfo/user
>
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