Hi Sunil, 2010/2/19 Sunil Khedar <su...@truesparrow.com>: > Hi All, > > I was going through the neo4j API. There are few things in API that are not > clear to me: > > 1. What other configuration options can be set for neo4j, apart from > storeDir? As in API all configuration related parameter methods are either > depricated or will be soon. A new configuration API will hopefully make it into version 1.1. Until then, please look at http://wiki.neo4j.org/content/Configuration_Settings > > 2. Can I traverse nodes using "INCOMING" or "OUTGOING" directions, if they > have BOTH direction relations? Relationships are always directed, so they always have a start node and an end node. This means that a relationship only have a direction given a context, i.e. what is the direction of relationship (A) if you're looking at it from node (N). Direction can be ignored in traversals and when you get relationships for a node, and this is where the BOTH direction is used. > > 3. How DynamicRelationshipType is different from RelationshipType? Following > is mentioned in API: > "Dynamic relationship type is persisted only when the first relationship of > this type is created." > I think DynamicRelationshipType is of no use untill it's used for the > first time. Please correct me if I am wrong. DynamicRelationshipType is just a simple implementation of RelationshipType interface in that it only implements the name() method. RelationshipType is just a wrapper around a String really and it specifies the name of the relationship type. Either you use enums to list your relationship type, so that they become compile-time checked in your code, f.ex:
public enum MyRelationshipTypes implements RelationshipType { KNOWS, LOVES, } ...or you can do it on the fly at runtime via f.ex. DynamicRelationshipType.withName( "KNOWS" ). The result of using the one or the other is identical. > > 4. How EmbeddedReadOnlyGraphDatabase and EmbeddedGraphDatabase are > different? As both of them are able to create nodes? Are nodes created by > EmbeddedReadOnlyGraphDatabase non-persistent? I think I am missing something > here. You cannot modify the graph in an EmbeddedReadOnlyGraphDatabase. The methods are there, but you'll get a RuntimeException when calling f.ex. createNode(). > > 5. How to make sure that ASYNC_OTHER_TX related indexing jobs are not lost? > How these jobs are triggered? Currently they aren't persisted, so if your indexing is critical, stick with the default configuration. > > 6. Can we define custom ReturnableEvaluator and StopEvaluator? Sure, just create implementations of those classes and pass such instances into the Node.traverse method. > > 7. While creating a node can we define the node id? If no, I think we have > to use lucene in-order to get the node ids. Please correct me if there is > any other way. No, the node (and relationship) ids are internal and you could rely on an IndexService (see http://components.neo4j.org/neo4j-index/) for lookups about other properties, f.ex. "uri" or "username" or such. > > > Thanks, > Sunil > > -- > Sr. Software Architect > Center of Excellence (COE) > True Sparrow Systems > _______________________________________________ > Neo mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > -- Mattias Persson, [matt...@neotechnology.com] Neo Technology, www.neotechnology.com _______________________________________________ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user