Thanks Peter, we'll look into Gremlin. =) But I'll push back a bit and say it would still ask for a feature like this to be a first-class feature of the REST API. If my app is e.g. in Python, it's not super API-friendly for me to have to write Java-ish code to achieve what I want.
I'd get it if what I was asking for was an uncommon edge case request. But for quite a while, this has been the one biggest pain point of Neo4j for us: how to return a meaningful subset of traverse results instead of all results. Having a paged traverser doesn't help at all if you can neither specify the order nor know what the default ordering is based on (I asked a while back and was told it's unspecified). (And again, by "order" here I mean beyond just "breadth first".) I'm all for simple, minimalistic and elegant APIs. I'm also all for being scenario-driven, and solving problems rather than building arbitrary features. So perhaps one solution here would be to introduce a new built-in "best first" order that's just like Djikstra's shortest-path API: you just specify a "cost" property (or function) for nodes and/or relationships. This would definitely solve our problem, and, I suspect, most people's problems in this regard. It wouldn't be a bulky feature that doesn't fit in (it would compliment Djikstra's very nicely), and it wouldn't require writing a complex Gremlin script to achieve this (I would think) common requirement. I'll get off the soapbox now. ;) Thanks for your consideration! Aseem On Thu, Aug 25, 2011 at 9:01 AM, Peter Neubauer < peter.neuba...@neotechnology.com> wrote: > See the other mail for a pointer :) > > Cheers, > > /peter neubauer > > GTalk: neubauer.peter > Skype peter.neubauer > Phone +46 704 106975 > LinkedIn http://www.linkedin.com/in/neubauer > Twitter http://twitter.com/peterneubauer > > http://www.neo4j.org - Your high performance graph database. > http://startupbootcamp.org/ - Öresund - Innovation happens HERE. > http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. > > > On Thu, Aug 25, 2011 at 1:00 AM, Matt Luongo <m...@scholr.ly> wrote: > > > +1, we could really use that. Client-side sorting sucks. > > > > -- > > Matt Luongo > > Co-Founder, Scholr.ly > > > > > > > > On Wed, Aug 24, 2011 at 4:43 PM, Aseem Kishore <aseem.kish...@gmail.com > > >wrote: > > > > > I've just spent a bunch of time reading into how one can control the > > > ordering of a traverse beyond simple "breadth first" or "depth first". > > More > > > precisely, even when breadth first, how one can control *which* > neighbors > > > are traversed first. > > > > > > (It matters less in which order they're traversed vs. which order > they're > > > returned if you're returning all results, since you can just sort on > the > > > client. But it matters a lot if you want to use the paged traverser, > > since > > > you're then only returning the first results.) > > > > > > I've learned that this is doable from Java by writing your own > > > BranchSelector implementation: > > > > > > http://components.neo4j.org/neo4j/1.4.1/apidocs/ > > > > > > I've found the built-in implementations, e.g. the pre-order > breadth-first > > > and depth-first: > > > > > > > > > > > > https://github.com/neo4j/community/blob/master/kernel/src/main/java/org/neo4j/kernel/PreorderBreadthFirstSelector.java > > > > > > > > > > > > https://github.com/neo4j/community/blob/master/kernel/src/main/java/org/neo4j/kernel/PreorderDepthFirstSelector.java > > > > > > To achieve a custom "best first", Igor Dovgiy for example shared that > he > > > modeled his implementation of the breadth-first selector, except just > > using > > > a PriorityQueue instead of a regular Queue. > > > > > > My question is: is there any way to specify this sort of thing over the > > > REST > > > API instead of having to write a plugin? If not, does that sound like a > > > reasonable feature request? > > > > > > I really just want something simple: nodes ordered by some "timestamp" > > > property. It's killing us that we can't do this today. We might just > have > > > to > > > look into writing this as a plugin... > > > > > > Thanks! > > > > > > 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
