can you please mail me the code, dataset and results as we too need to evaluate neo4j and your code will come handy thanx
On 6/29/11, Agelos Pikoulas <agelos.pikou...@gmail.com> wrote: > My problem pattern is exactly the same as Niels's : > > A dense-node has millions of relations of a certain direction & type, > and only a few (sparse) relations of a different direction and type. > The traversing is usually following only those sparse relationships on those > dense-nodes. > > Now, even when traversing on these sparse relations, neo4j becomes extremely > slow > on a certainly non linear Order (the big cs O). > > Some tests I run (email me if u want the code) reveal that even the number > of those dense-nodes in the database greatly influences the results. > > I just reported to Michael the runs with the latest M05 snapshot, which are > not very positive... > I have suggested an (auto) indexing of relationship types / direction that > is used by traversing frameworks, > but I ain't no graphdb-engine expert :-( > > A' > > > Message: 5 >> Date: Wed, 29 Jun 2011 18:19:10 +0200 >> From: Niels Hoogeveen <pd_aficion...@hotmail.com> >> Subject: Re: [Neo4j] traversing densely populated nodes >> To: <user@lists.neo4j.org> >> Message-ID: <col110-w326b152552b8f7fbe1312d8b...@phx.gbl> >> Content-Type: text/plain; charset="iso-8859-1" >> >> >> Michael, >> >> >> >> The issue I am refering to does not pertain to traversing many relations >> at >> once >> >> but the impact many relationship of one type have on relationships >> >> of another type on the same node. >> >> >> >> Example: >> >> >> >> A topic class has 2 million outgoing relationships of type "HAS_INSTANCE" >> and >> >> has 3 outgoing relationships of type "SUB_CLASS_OF". >> >> >> >> Fetching the 3 relations of type "SUB_CLASS_OF" takes very long, >> >> I presume due to the presence of the 2 million other relationships. >> >> >> >> I have no need to ever fetch the "HAS_INSTANCE" relationships from >> >> the topic node. That relation is always traversed from the other >> direction. >> >> >> >> I do want to know the class of a topic instance, leading to he topic >> class, >> >> but have no real interest ever to traverse all topic instance from the >> topic >> >> class (at least not directly.. i do want to know the most recent addition, >> >> and that's what I use the timeline index for). >> >> >> >> Niels >> >> >> > From: michael.hun...@neotechnology.com >> > Date: Wed, 29 Jun 2011 17:50:08 +0200 >> > To: user@lists.neo4j.org >> > Subject: Re: [Neo4j] traversing densely populated nodes >> > >> > I think this is the same problem that Angelos is facing, we are >> > currently >> evaluating options to improve the performance on those highly connected >> supernodes. >> > >> > A traditional option is really to split them into group or even kind of >> shard their relationships to a second layer. >> > >> > We're looking into storage improvement options as well as modifications >> to retrieval of that many relationships at once. >> > >> > Cheers >> > >> > Michael >> > _______________________________________________ > Neo4j mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > -- Aliabbas Petiwala M.Tech CSE _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
