filament: All content tagged as filament in NoSQL databases and polyglot persistence
Pere Urbón ☞ published a short review of a couple of existing graph databases. For your reference, below are the ones reviewed in the post and a couple more that we’ve previously mentioned here on myNoSQL:
☞ Neo4j is an embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables.
☞ DEX is a high performance library to manage very large graphs or networks
☞ HyperGraphDB: a general purpose, extensible, portable, distributed, embeddable, open-source data storage mechanism.
☞ InfoGrid: an Internet Graph Database with a many additional software components that make the development of REST-ful web applications on a graph foundation easy.
☞ vertexdb: a high performance graph database server that supports automatic garbage collection.
Note: by checking the project homepage I cannot tell if the project is still active or not.
☞ AllegroGraph RDFStore: a modern, high-performance, persistent RDF graph database.
Note: AllegroGraph seems to be positioned in the RDF stores space, which features some other solutions too.
☞ Filament: a graph persistence framework and associated toolkits based on a navigational query style.
☞ Sones GraphDS provides an inherent support for high-level data abstraction concepts (graph structures, walks, consistency, editions, revisions, copies), its own Graph Query Language, an underlying distributed file system and various interfaces like SOAP, REST or WebDAV.
And I’m not sure these are all …
Update: make sure you check the NoSQL Graph Database Matrix
As I said in MongoDB MapReduce tutorial, the best way to validate that you’ve got the basics right about a system is to use some basic code. And this is exactly the idea behind this post: to take a look at a very (very) basic tagging app in InfoGrid and Neo4j.
The code with more details can be found ☞ here.
The Neo4j code was contributed by Mattias Persson from Neo Technology (thanks Mattias).
Note: I couldn’t figure out a way to make the code more readable that this. But you can hover over the code snippets and you’ll get the option to see the original source code.
Here are my notes about the two code snippets above:
- everything in Neo4j must happen inside a transaction even if it’s a graph traversal operation (this gives a very strong Isolation level). The InfoGrid traversal code seem to happen outside the transaction, so it sounds like it supports a more relaxed isolation level (interesting question here is: if traversal would happen inside a transaction, would that isolate it from seeing possible external modifications?)
- InfoGrid’s central element is
MeshObject, while Neo4j has
Relationship. Generally speaking I have found the terminology in InfoGrid a bit more unusual (f.e.
- the Neo4j uses also the
LuceneIndexServicefor indexing both the tag and web resources nodes, but that’s only becaus e the code there makes sure not to duplicate either tags or web resources (i.e. this functionality is not present in the InfoGrid code and I don’t know how that would look like)
- in both cases a relationship gives you access at both its ends. While both InfoGrid and Neo4j documentation speak about bidirectional arcs
Update: The guys from Sones picked up my challenge and they show up their C# implementation on this ☞ post. I have included below the code for reference
Update: I’ve just got another submission from Filament. Code is included below and their original post is ☞ here