2011/3/2 Pablo Pareja <[email protected]>: > Hi! > > I just checked the wiki looking for information on how to index > relationships in batch insertion mode but > didn't find anything so far. > This can be found in the wiki regarding relationship indexing: > > RelationshipIndex friendships = graphDb.index().forRelationships( > "friendships" ); > // "type" isn't a reserved key and isn't indexed automatically > Relationship relationship = friendships.get( "type", "knows", morpheus, > trinity ).getSingle(); > > However I cannot find any code snippet for adding relationships to the > index, not just querying it. > How can these two different cases (*batch insertion and standard mode*) be > carried out?
It's just like adding to a node index. a RelationshipIndex extends Index<Relationship> so adding to a RelationshipIndex is: RelationshipIndex relIndex = ... relIndex.add( myRelationship, "key", "value" ); I'll add it to the wiki as well. > > Besides that, I was wondering how node relationships retrieval is > implemented. > In my domain model I have some nodes which have hundred of thousands of > relationships, including different types of them. > > Suppose you are already situated on one of these nodes and you want to get > only one specific type of incoming relationships, > retrieval time would be dependent on how many relationships are there > including other types? > or once you specify the relationship type in the node.getRelationships(...) > method it doesn't matter how many relationships are there > of other types in terms of relationship retrieval time? I'd really like to answer: "it doesn't matter". But currently it does... there are two phases here: one where the relationships aren't cached in memory yet (or have fallen out of memory to make room for loading other relationships). Then loading relationships, whether a specific type or all is linear to how many relationships there are on that node. The other is when the node is fully cached with all its relationships and you get relationships of a specific type(s). Then it won't matter how many relationships there are other then for the given type(s). Direction for those relationships is filtered when you get them, but I think soon the cache layer will also optimize on direction so that not even filtering will be required when getting relationships of a specific type and direction. There are some thoughts about also making the storing/loading of relationships type-and-direction-aware so that the number of relationships (outside of your given type/direction) really won't matter. Will probably be a while before such a thing even has a chance to make it in though. > > Thanks in advance, > > Pablo > > -- > Pablo Pareja Tobes > LinkedIn http://www.linkedin.com/in/pabloparejatobes > Twitter http://www.twitter.com/pablopareja > > http://about.me/pablopareja > http://www.ohnosequences.com > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user > -- Mattias Persson, [[email protected]] Hacker, Neo Technology www.neotechnology.com _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
