[Neo] Relation properties

Anton Popov popov.UA.work at gmail.com
Mon Feb 1 11:49:53 CET 2010


Hello Rick,

I've tried to set my own ID to be able to quickly find my relations, because
of unavailable relation indexing functionality. As far as I can see I will
make changes to LuceneIndex.

On 29 January 2010 17:48, Rick Bullotta <
rick.bullotta at burningskysoftware.com> wrote:

> Why do you need to set your own ID's?  You can use the relationship's
> built-in as your index key (it is guaranteed to be unique) and
> getRelationshipByID to retrieve the relationship.  You'd need to very
> slightly extend the LuceneIndex stuff to deal with relationships, but it
> shouldn't be difficult.
>
> -----Original Message-----
> From: user-bounces at lists.neo4j.org [mailto:user-bounces at lists.neo4j.org]
> On
> Behalf Of Anton Popov
> Sent: Friday, January 29, 2010 9:31 AM
> To: Neo user discussions
> Subject: Re: [Neo] Relation properties
>
> And as far as I can see there is no way to set my own id'es for Relations?
> Only Nodes has such functionality - am I right?
>
> ---------- Forwarded message ----------
> From: Anton Popov <popov.UA.work at gmail.com>
> Date: 2010/1/29
> Subject: Re: [Neo] Relation properties
> To: Neo user discussions <user at lists.neo4j.org>
>
>
> Hello Mattias,
>
> Got it. Thanks.
> Is there any RoadMap available?
>
> 2010/1/29 Mattias Persson <mattias at neotechnology.com>
>
> Unfortunately you cannot index Relationships, but it's a (frquently
> > requested) feature we're planning to add.
> >
> > 2010/1/29 Anton Popov <popov.UA.work at gmail.com>:
> > > Hello everybody,
> > >
> > > A related question is can I index both Nodes & Relations?
> > > As I can see LuceneIndexBatchInserter.index( long node, String key,
> > Object
> > > value ) applies for Nodes only.
> > >
> > > 2010/1/28 Mattias Persson <mattias at neotechnology.com>
> > >
> > >> Not at all, you're not the first one to overlook that inheritance!
> > >>
> > >> 2010/1/28, Anton Popov <popov.UA.work at gmail.com>:
> > >> > Thanks for a quick answer, Mattias.
> > >> >
> > >> > Sorry for a stupid questions, just haven't noticed the inheritance
> of
> > >> > Relationship interface.
> > >> >
> > >> > On 28 January 2010 19:43, Mattias Persson <
> mattias at neotechnology.com>
> > >> wrote:
> > >> >
> > >> >> Relationship has all the property methods, just like Node...
> they're
> > >> >> actually on PropertyContainer (a common super interface to Node and
> > >> >> Relationship) see
> > >> >> http://api.neo4j.org/current/org/neo4j/graphdb/Relationship.htmland
> > >> >>
> > http://api.neo4j.org/current/org/neo4j/graphdb/PropertyContainer.html
> > >> >> for more information.
> > >> >>
> > >> >> So to manage the cost in a dijkstra algorithm you can use whatever
> > >> >> property key, f.ex. "weight", like this:
> > >> >>
> > >> >>    Relationship rel = ... // any relationship
> > >> >>    rel.setProperty( "weight", 4 );
> > >> >>
> > >> >> And if you're using the Dijkstra algorithms in the
> "neo4j-graph-algo"
> > >> >> component, http://components.neo4j.org/neo4j-graph-algo/ , you can
> > >> >> instantiate it with a CostEvaluator instance something like this:
> > >> >>
> > >> >>    new CostEvaluator<Integer>()
> > >> >>    {
> > >> >>        CostType getCost( Relationship relationship, boolean
> backwards
> > )
> > >> >>        {
> > >> >>            / TODO Handle backwards flag?
> > >> >>            return ( Integer ) relationship.getProperty( "weight", 1
> > );
> > >> >>        }
> > >> >>    }
> > >> >>
> > >> >> ...and pass it to your Dijkstra algo instance.
> > >> >>
> > >> >> Is this what you were looking for?
> > >> >>
> > >> >> 2010/1/28 Anton Popov <popov.UA.work at gmail.com>:
> > >> >> > Hello everyone,
> > >> >> >
> > >> >> > Is there any possibility to assign properties to Relations?
> > >> >> > The matter is I want to try Dijkstra algorithm performance on
> some
> > >> >> weighted
> > >> >> > directed graph and don't know where to put weight actually...
> > >> >> >
> > >> >> > --
> > >> >> > Best regards,
> > >> >> > Popov Anton
> > >> >> > _______________________________________________
> > >> >> > Neo mailing list
> > >> >> > User at lists.neo4j.org
> > >> >> > https://lists.neo4j.org/mailman/listinfo/user
> > >> >> >
> > >> >>
> > >> >>
> > >> >>
> > >> >> --
> > >> >> Mattias Persson, [mattias at neotechnology.com]
> > >> >> Neo Technology, www.neotechnology.com
> > >> >> _______________________________________________
> > >> >> Neo mailing list
> > >> >> User at lists.neo4j.org
> > >> >> https://lists.neo4j.org/mailman/listinfo/user
> > >> >>
> > >> >
> > >> >
> > >> >
> > >> > --
> > >> > Best regards,
> > >> > Popov Anton
> > >> > _______________________________________________
> > >> > Neo mailing list
> > >> > User at lists.neo4j.org
> > >> > https://lists.neo4j.org/mailman/listinfo/user
> > >> >
> > >>
> > >>
> > >> --
> > >> Mattias Persson, [mattias at neotechnology.com]
> > >> Neo Technology, www.neotechnology.com
> > >> _______________________________________________
> > >> Neo mailing list
> > >> User at lists.neo4j.org
> > >> https://lists.neo4j.org/mailman/listinfo/user
> > >>
> > >
> > >
> > >
> > > --
> > > Best regards,
> > > Popov Anton
> > > _______________________________________________
> > > Neo mailing list
> > > User at lists.neo4j.org
> > > https://lists.neo4j.org/mailman/listinfo/user
> > >
> >
> >
> >
> > --
> > Mattias Persson, [mattias at neotechnology.com]
> > Neo Technology, www.neotechnology.com
> > _______________________________________________
> > Neo mailing list
> > User at lists.neo4j.org
> > https://lists.neo4j.org/mailman/listinfo/user
> >
>
>
>
> --
> Best regards,
> Popov Anton
>
>
>
> --
> Best regards,
> Popov Anton
> _______________________________________________
> Neo mailing list
> User at lists.neo4j.org
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>
> _______________________________________________
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>



-- 
Best regards,
Popov Anton


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