On Wed, Mar 2, 2011 at 11:00 AM, Mattias Persson <[email protected]>wrote:
> 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. > Thanks ;) Just one more question about this, what if you want to index a relationship not by any property but only by the nodes involved? I've seen than once the relationship has been indexed, you can query the index with start/end node parameters; but how can I index it in the case where I only care about these nodes and not any key-value pair? > > > > > 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. > > Ok, that's actually what I thought after running some test-cases; however I somehow was hoping it wouldn't be that way and what happened was just that I was doing something wrong. This means then that at least in my case I'll have to index a fairly big amount of relationships in order to achieve decent retrieval times for highly connected nodes. Any advice/suggestion for tunning performance in these cases apart from relationship indexation? Cheers, Pablo > > > > 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 > -- 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
