As to how the pattern matching works (I believe): Worst case scenario is a linear scan (from the starting points given), but it tries to prune branches/paths as quickly it finds out that there's no longer any need to go further (as soon as there are pattern mismatches) and instead continues down other branches.
2011/6/18 Andres Taylor <andres.tay...@neotechnology.com> > Are you referring to what the implementation looks like? This is the > source. > I haven't grokked it yet, so I can't give you a TL;DR;, sorry. > > https://github.com/neo4j/community/tree/master/graph-matching > > Cypher allows you to do graph-matching (internally, it uses the above > module), but adds a few more bells and whistles to it. > > If you have any Cypher questions, ask away. > > Andrés > > On Sat, Jun 18, 2011 at 8:13 PM, Aman <aman.6...@gmail.com> wrote: > > > Jim, > > I was going through Cypher and a question came into my mind regarding > > pattern matching... How is pattern matching done in neo4j? I mean, how > > are nodes and relationships matched in case of large data-sets? > > > > On 6/18/11, Aman <aman.6...@gmail.com> wrote: > > > Jim, > > > Thanks for the valuable input... The use case I mentioned here (using > > > only visited places) was a simplistic version of the real one, > > > because, just as you said, I'd be getting large number of results in > > > that case... I'd check out pattern matching and Cypher to ease me in > > > my project... Neo4j team is truly awesome! You guys are always there > > > to help... > > > > > > On 6/18/11, Jim Webber <j...@neotechnology.com> wrote: > > >> That's a great point. > > >> > > >> In Neo4j you can add properties to your relationships so that: > > >> > > >> Jim --VISITED (numberOfTimes: 20) --> Melbourne > > >> > > >> Then you can use the "numberOfTimes" property to determine whether or > > not > > >> you'd like to include the person/city in the recommendations you're > > >> making. > > >> In this case it seems I'm rather keen on Melbourne, so you might want > to > > >> recommend me to other folks who visit Melbourne a lot. > > >> > > >> As for whether it's more efficient than other databases, I suspect it > is > > >> in > > >> the general case since this is a graph operation which other kinds of > > >> stores > > >> will have to reify for themselves (e.g recursive joins, big map/reduce > > >> job, > > >> etc). The cost of these kind of operations in Neo4j tends to be very > > low. > > >> > > >> Jim > > >> > > >> > > >> On 18 Jun 2011, at 07:56, faja...@gmail.com wrote: > > >> > > >>> Ah this discussion is interesting, I want to join and throw in sonme > > >>> idea > > >>> too. > > >>> > > >>> If a user can visit a place for multiple times. And if there are 100 > > >>> user > > >>> visit USA. So we should suggest top 10 only. > > >>> > > >>> Would traversing the graph be more efficient than normal database > > query? > > >>> > > >>> > > >>> Sent from my BlackBerry® smartphone from Sinyal Bagus XL, Nyambung > > >>> Teruuusss...! > > >>> > > >>> -----Original Message----- > > >>> From: Aman <aman.6...@gmail.com> > > >>> Sender: user-boun...@lists.neo4j.org > > >>> Date: Sat, 18 Jun 2011 10:50:34 > > >>> To: Neo4j user discussions<user@lists.neo4j.org> > > >>> Reply-To: Neo4j user discussions <user@lists.neo4j.org> > > >>> Subject: Re: [Neo4j] Generating suggestions in a Neo4j db > > >>> > > >>> Hi Jim, > > >>> The way you mentioned, that will take care of these suggestions, > > >>> thanks for the same. But here's a tougher problem.... > > >>> If I have a database of 50k people, and I want to find friends based > > >>> upon the places that those 50k people have visited (i.e. People who > > >>> have visited same places as me should be suggested as friends to me), > > >>> then how to to that... I've thought all that I could, but I always > > >>> come up with something stupid... Any suggestions about this? > > >>> > > >>> On 6/18/11, Aman <aman.6...@gmail.com> wrote: > > >>>> Hi Jim, > > >>>> The way you mentioned, that will take care of these suggestions, > > >>>> thanks for the same. But here's a tougher problem.... > > >>>> If I have a database of 50k people, and I want to find friends based > > >>>> upon the places that those 50k people have visited (i.e. People who > > >>>> have visited same places as me should be suggested as friends to > me), > > >>>> then how to to that... I've thought all that I could, but I always > > >>>> come up with something stupid... Any suggestions about this? > > >>>> > > >>>> On 6/18/11, Jim Webber <j...@neotechnology.com> wrote: > > >>>>> Hi Aman, > > >>>>> > > >>>>> I'm puzzled. > > >>>>> > > >>>>> Why not > > >>>>> > > >>>>> Aman--HAS_VISITED-->USA > > >>>>> Jim--HAS_VISITED-->India > > >>>>> > > >>>>> And if: > > >>>>> > > >>>>> Aman--FRIEND-OF-->Jim > > >>>>> > > >>>>> Then you just need to traverse from Aman following outgoing > FRIEND_OF > > >>>>> relationships to all your friends, and then traverse out their > > >>>>> outgoing > > >>>>> HAS_VISITED relationships to find places your friends have been. > > >>>>> > > >>>>> The general idiom with Neo4j is use indexes the find your start > node > > >>>>> (e.g. > > >>>>> the Aman node in the above) then traverse from there. > > >>>>> > > >>>>> Jim > > >>>>> > > >>>>> _______________________________________________ > > >>>>> Neo4j mailing list > > >>>>> User@lists.neo4j.org > > >>>>> https://lists.neo4j.org/mailman/listinfo/user > > >>>>> > > >>>> > > >>>> > > >>>> -- > > >>>> Amandeep > > >>>> +91-9878483857 > > >>>> > > >>> > > >>> > > >>> -- > > >>> Amandeep > > >>> +91-9878483857 > > >>> _______________________________________________ > > >>> Neo4j mailing list > > >>> User@lists.neo4j.org > > >>> https://lists.neo4j.org/mailman/listinfo/user > > >>> _______________________________________________ > > >>> Neo4j mailing list > > >>> User@lists.neo4j.org > > >>> https://lists.neo4j.org/mailman/listinfo/user > > >> > > >> _______________________________________________ > > >> Neo4j mailing list > > >> User@lists.neo4j.org > > >> https://lists.neo4j.org/mailman/listinfo/user > > >> > > > > > > > > > -- > > > Amandeep > > > +91-9878483857 > > > > > > > > > -- > > Amandeep > > +91-9878483857 > > _______________________________________________ > > Neo4j mailing list > > User@lists.neo4j.org > > https://lists.neo4j.org/mailman/listinfo/user > > > _______________________________________________ > Neo4j mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > -- Mattias Persson, [matt...@neotechnology.com] Hacker, Neo Technology www.neotechnology.com _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
