Thanks for the input, Michael and Josef! I'm intrigued by the possibility of being able to have comment threads, etc. when you consider a tagging action as an event, and thus consider it a node in the graph.
I'm worried though about having the duplicate edges. How do you make sure everything remains consistent? If I delete a tag, do you delete the node for the previous tag event too? Or just the edge? If you delete the node too, that deletes the comment thread too then? Some great food for thought. Let me chew on this a bit more and get back to you guys. Thanks again, Aseem On Thu, Jun 9, 2011 at 1:55 AM, Josef Holy <ho...@centrum.cz> wrote: > > Hi, > > few notes from the top of my head on how we modeled this in the past: > > User is a Node > Resource (Document) is a Node > Tag is a Node (having a label, language property, can be connected via > relationships to other Tag Nodes representing its synonyms, can become a > concept in (tree-)structured thesauri, etc...) > > Scenario: User U tags Resource R with Tag T: > - Create special 'TaggingEvent' TE Node, with timestamp property and > connect it to U, R and T by creating [TE, U], [TE, R] and [TE, T] > relationships > - TE nodes are indexed by timestamp, allowing to easily generate 'Tag > activity streams' for different contexts - for users, resources or even tags > (if it makes sense) > - create some additional relationship(s) as needed between [U, T], [U, R] > and [T, R] to simplify graph traversals and also to aggregate/cache the > information like 'how many times was given R tagged with given T ~ this is > f.e. expressed by some 'weight' property on the [T,R] relationship - and > comes handy for generating things like tag clouds (~ get all [T,R] > relationships with their weights) > > Scenario: User U bookmarks Resource R: > - here it may be enough to create only [U,R] relationship with properties > like timestamp, but we followed similar model as above - create special > 'BookmarkEvent' Node BE, with timestamp and ralationships [BE, U] and [BE, > R] and [U,R] > - this again allows to easily create bookmarking activity streams, or to > mix tagging+bookmarking events into one stream, if there is a requirement to > do so. > > > That's about it. > > Hope this helps. > > > Regards, > > Josef. > > -- > www.subject.cz > > ______________________________________________________________ > > Od: "Max De Marzi Jr." <maxdema...@gmail.com> > > Komu: Neo4j user discussions <user@lists.neo4j.org> > > Datum: 09.06.2011 08:21 > > Předmět: Re: [Neo4j] Design question: Del.icio.us > > > >Aseem, > > > >Which users tagged what? SELECT DISTINCT user_id FROM USER_TAGS WHERE > >bookmark_id = x > >Which bookmarks did a user tag? SELECT DISTINCT bookmark_id FROM > >USER_TAGS WHERE user_id = x > >Which bookmarks were tagged with x? SELECT DISTINCT bookmark_id FROM > >USER_TAGS WHERE tag_id = x > > > >What question are you trying to answer that you can't get from a > >relational table? > > > >I think it's better to make your model depending on the questions you > >are trying to answer. > > > >I have a similar model (users tagging users) and I needed to answer: > >Which users have been tagged by me or my network 6 degrees out? > >What is the tagged distance a user is away from another user? > > > >Turns out, all I needed was User nodes with Tagged links. User -> > >tagged -> User -> tagged -> User > >Everything else I get from the relational db. > > > >When I start to care about which users have been tagged for by me or > >my network 6 degrees out for this KEYWORD, then I'll create a more > >complex model: > >User -> UserKeyword -> tagged -> UserKeyword -> User > > Keyword ---/ Keyword ---/ > > > >Regards, > >Max > > > >On Thu, Jun 9, 2011 at 12:33 AM, Aseem Kishore <aseem.kish...@gmail.com> > wrote: > >> Also forgot to add: now if you want to show all links (globally) for a > given > >> tag, how do you do that? Are you indexing each tag-link (as a key-value > >> pair) every time a tag is added? Removing from the index every time a > tag is > >> deleted? > >> > >> Thanks, > >> > >> Aseem > >> > >> On Wed, Jun 8, 2011 at 10:31 PM, Aseem Kishore <aseem.kish...@gmail.com > >wrote: > >> > >>> I forgot to state this, but a key requirement of tags of course is that > you > >>> can apply multiple of them to the same link. > >>> > >>> Would you still go that route then? > >>> > >>> If you want to delete a link from your bookmarks, it's a matter then of > >>> deleting each tag edge? > >>> > >>> Aseem > >>> > >>> > >>> On Wed, Jun 8, 2011 at 10:28 PM, Siddhartha Kasivajhula < > >>> countvajh...@gmail.com> wrote: > >>> > >>>> Couldn't you use edges for "tags" instead of nodes? > >>>> > >>>> user1 --tag--> link1 > >>>> user2 --tag--> link1 > >>>> user1 --tag--> link2 > >>>> > >>>> > >>>> On Wed, Jun 8, 2011 at 10:23 PM, Aseem Kishore < > aseem.kish...@gmail.com > >>>> >wrote: > >>>> > >>>> > Hi guys, > >>>> > > >>>> > We're thinking about implementing tags in our system, and we're > >>>> pondering a > >>>> > few ideas for how we'd go about it, and none of them seem perfect. > I'd > >>>> like > >>>> > to ask you guys: how would you design an analogous case: > Del.icio.us? > >>>> > > >>>> > At the core, *users bookmark links*, so it makes sense to have > "users" > >>>> and > >>>> > "links" as types of nodes, and "bookmark" as the type of edge that > >>>> connects > >>>> > them. Now, you can see all the links a given user has bookmarked, > and > >>>> all > >>>> > the users that have bookmarked a given link. > >>>> > > >>>> > Now users can also *tag* links, of course, but the most interesting > >>>> > requirement is that, when I'm looking at *my links*, I only want to > see > >>>> *my > >>>> > tags*. Thus, tags can't be tied just to links; they have to be tied > to > >>>> > users > >>>> > too. But most importantly, you have to maintain *which* user and > *which* > >>>> > link *each* tag is for. > >>>> > > >>>> > Thus, it seems most intuitive to us if we could have "tags" be nodes > >>>> > that *point > >>>> > to the "bookmark" edges*. Unfortunately, that's a hypergraph, which > >>>> Neo4j > >>>> > doesn't support. > >>>> > > >>>> > We could use intermediate nodes for bookmarks maybe, but that sort > of > >>>> sucks > >>>> > to lose the intuitiveness of the graph and introduce redundant > edges, > >>>> more > >>>> > complexity which makes consistency harder, etc. > >>>> > > >>>> > We have some other ideas, but I'm curious if any of you guys have > >>>> thought > >>>> > about this already or have done it, or if you guys have thoughts. > Thanks > >>>> in > >>>> > advance! > >>>> > > >>>> > Aseem > >>>> > _______________________________________________ > >>>> > 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 > >> > >_______________________________________________ > >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
