you can use category nodes to connect nodes of a certain type to. then you can count the nodes using a traversal
you dont have to go via an index to do things like that Sent from my iBrick4 Am 14.06.2011 um 17:10 schrieb Marko Rodriguez <[email protected]>: > Hi, > >> Is it possible that when we create the Automatic Index, that we can filter >> it on specific nodes? > > No. > >> Referring to the diagram below, we have a Node with a property _Type= >> Agency. I would like to create an index (aidx-agency-key) based on Key but >> only for the Nodes with _Type=Agency. >> So, pseudo code would be: >> g.createAutomaticIndex('myIndex', Vertex.class, new pair[,] >> {Node._Type=Agency},“Key”) >> >> Is this the right approach, or are we doing something wrong > > You can't do that with AutomaticIndices. > >> The solution we want is to be able to count all the Nodes in the database >> with a property _Type=Agency and property Key=”myKey” or to checking the >> existence of a Node with _Type=”Agency” and Key=”myKey”. > > Yea. The not so efficient way to do that is: > > g.idx('myIndex').get('_Type','Agency')[[key:'myKey']].count() > > 1. get agencies > 2. iterate and filter out those whose key doesn't equal 'myKey' > 3. count up what gets emitted from the pipeline. > > Perhaps Neo4j guys can help as there are some things with Lucene indices and > the 'AND' clause. Given that AutomaticIndex, when used with Neo4jGraph, is > just a wrapper to Lucene, I believe you can do stuff like '_Type AND > Key=myKey' ? -- I've never done it so I don't know... Rick, on this list, > knows the ins and outs of indices.... > >> >> and to do a count or check if it exists would be multiple filters >> g.V[[_Typey:Agency],[ Name:Acme]].count() > > Yea, thats a bit excessive -- too many things to iterate through. You can do > the previous: > g.idx('myIndex').get('_Type','Agency')[[key:'myKey']].count() > >> > > Good luck, > Marko. > > http://markorodriguez.com > > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
