Hi, Following on from a couple of recent posts and points that were raised I thought I'd outline some of my impressions of using Neo over the last 2-3 months and hopefully it'll be useful to some and/or start some discussion.
i) Indexing and querying. One of my use cases needed the ability to query node properties using complex queries - basically exactly the thing Lucene provides. Now, having used the Compass project very successfully in another project I looked there as a potential solution over and above the provided Lucene indexer. It was pretty easy to get integrated via their resource concept and it provides i) transactions ii) configuration via and integration with Spring (eg @Transactioned) iii) ability to define searchable resources, type mappings and various other Lucene properties in configurations files. Could be a potential starting point of better integrated indexer that has been mentioned a few times? The project also has event based integration with various ORM technologies so it's not too much of a stretch to think that it could be extended to provide event based index updating in Neo. ii) Remote access. This was an initial worry about the applicability of Neo to my project. My clients are Swing based and so distributed and need to talk to a server to get their data. The solution I'm currently using, which is working well, is a service using Neo as an underlying data store that sends either GraphML or TreeML documents back to my swing clients, depending on the use case. This initially required a little rework of the solution I was migrating from (an RDF store accessed remotely) but I actually think it's improved the architecture of the solution. The GraphML and TreeML representations are being used since the display technology I'm using, prefuse, has the capability of reading that format and I went with that for ease of prototype development. So far it's working well and I have no plans of moving to another data transfer format. iii) Data entry. My project is aimed at integrating data from multiple different sources and so one of the very nice features of the Sesame RDF store I was previously using was the ability to import datasources from common file formats. Neo has no such capability and it is missed, although it also wasn't too hard to invent my own and write the parsers for it. iv) Data updated. Another requirement of my project is the ability to update data in the graph as new versions become available. Since I'm taking data from multiple different sources these updates don't happen concurrently, but they do occur as a batch release requiring a deletion of the old data followed by an insert of the new. The sesame store had a nice solution to this exact problem (which was driven by real life experience) in that data could be tagged with a specific context and data in a specific context could be deleted, and re-uploaded, independently from the rest of the graph. I'm still thinking about ways to achieve something similar with Neo. v) Graph data format. The reason I am using Neo and was previously using RDF is that the data I'm working with is naturally a graph, and so they make sense. What I ended up disliking about RDF is that everything is treated as a graph node and relationships, and so the semantic graph of entity relationships gets confused with the syntatic graph of representing entity properties. This led to some very nasty code to tease these apart. Neo gets over this by providing node (and edge) properties that allow entity (and relationship) properties to be represented naturally resulting in a clean graph of entity relationships. vi) The other major advantage Neo has over RDF is traversal. I have use cases that need it and it was my feeble attempts to implement this over an RDF store that was the final straw that made me move to Neo. I'm still learning to appreciate the power of traversals and this, at least for me, was the major conceptual hurdle in using Neo. thanks, Jonny _______________________________________________ Neo mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
