While working on Enhanced API, I realize two crucial method are missing on the Node interface of the standard API:
RelationshipType[] getRelationshipTypes(); RelationshipType[] getRelationshipTypes(Direction); For Enhanced API, I'd like to be able to plug in different Relationship implementations (eg. SortedRelations and HyperRelations). Doing so is sort of possible, but only by cluttering a class called ElementImpl with all sorts of logic related to those different Relationship implementations (not the place where it belongs). The neat way would be to dispatch on RelationshipType and have the different Relationship implementations handle that logic. The API for PropertyContainer on the other hand does provide a method similar to what I am asking for: PropertyContainer#getPropertyKeys(). I realize this request cannot be honored without changing the record layout of the neo4j store, which has a major impact. However, there is already good reason to reconsider the record layout of the relationship store to solve the issue of densely connected nodes. To properly solve the densely connected node issue, relationships should be partitioned by relationship type and by direction. That way only those Relationships belonging to a RelationshipType that contributes to the densely connectedness will take time to load, while other Relationships can be fetched fast. Such partitioning immediately provides the meta information I am asking for. Such meta information (as exists for properties), has value beyond its use in the Enhanced API. I would eg. like to be able to present a form with the property keys and RelationshipTypes associated with a particular Node, and on request load the content belonging to a property key or a RelationshipType. For property keys this is possible, but for RelationshipTypes all relationships need to be fetched to know which RelationshipTypes are associated with a particular node. Especially for RelationshipTypes with many instances connected to one Node this is not a suitable solution and runs counter to the need to load those relationships on request. Niels _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
