Graph database: All content tagged as Graph database in NoSQL databases and polyglot persistence
Scroll to minute 16:55 of this video to watch Jim Webber explain the benefits of polyglot persistence and how starting (again) the winner-takes-it-all war is just sending us back at least 10 years from the database Nirvana.
We’ve just come from the place where one-size-fits-all and we don’t want to go back there. There is a huge wonderful ecosystem of stores. Pick the right one. Don’t just assume that the one you find the easiest or the one that shouts the loudest is the one you’re going to use. Pick the one that suits your data model.
It doesn’t matter what flavor of relational or NoSQL database you prefer or have experience with or if a small or large database vendor is paying your bills. You really need to get this right as otherwise we’re just going to destroy a lot of valuable options we’ve added to our toolboxes.
Original title and link: The Database Nirvana ( ©myNoSQL)
Very good slidedeck from Max de Marzi introducing Neo4j’s Cypher query language. While you’ll have to go through the 50 slides yourself to get the details, I’ve extracted a couple of interesting bits:
- Cypher was created because Neo4j Java API was too verbose and Gremlin is too prescriptive
- SPARQL was designed for a different data model and doesn’t work very well with a graph database
- Cypher design decisions:
- ASCII-art patterns (nb: when first sawing Cypher I haven’t thought of this, but it is cool)
- external DSL
- SQL familiarity (nb: as much as it’s possible with a radically different data model and processing model)
Marco A. Rodriguez in Exploring Wikipedia with Gremlin Graph Traversals:
There are numerous ways in which Wikipedia can be represented as a graph. The articles and the href hyperlinks between them is one way. This type of graph is known a single-relational graph because all the edges have the same meaning — a hyperlink. A more complex rendering could represent the people discussed in the articles as “people-vertices” who know other “people-vertices” and that live in particular “city-vertices” and work for various “company-vertices” — so forth and so on until what emerges is a multi-relational concept graph. For the purpose of this post, a middle ground representation is used. The vertices are Wikipedia articles and Wikipedia categories. The edges are hyperlinks between articles as well as taxonomical relations amongst the categories.
Imagine the reachness of the model you’d achieve when every piece of data and metadata would become a vertex or an edge. It’s not just the wealth of data but also the connectivity. Time would be the only missing dimension.
Original title and link: The Richness of the Graph Model: The Sky Is the Limit ( ©myNoSQL)
Two new releases in the graph databases space:
DEX Graph Database 4.5
The new DEX Graph Database release comes with pre-packaged graph algorithms—breadth and depth first traversal, shortest path, Gabow connectivity—available for Java, .NET, and C++. You can get the new version from here.
Neo4j 1.7 Milestone 1
As per Neo4j 1.7 milestone 1 update, this version features:
- improved Cypher
- SSL support
- improved Neo4j documentation
- high availability improvements (nb: there are recommended maintenance releases for Neo4j 1.5 and 1.6)
- upgraded Blueprints and Gremlin support
You can get Neo4j 1.7 from here.
Original title and link: Graph Databases Updates: DEX Graph Database 4.5 and Neo4j 1.7 Milestone 1 ( ©myNoSQL)
Even if my first post about the Micosoft research graph database Trinity is back from March last year, I haven’t heard much about it since. Based on my tip, Klint Finley published an interesting speculation about Trinity, Dryad, Probase, and Bing. Since then though, Microsoft moved away from using Dryad to Hadoop and I’m still not sure about the status of the Trinity project. But I have found a paper about the Trinity graph engine authored by Bin Shao, Haixun Wang, Yatao Li. You can read it or download it after the break.
We introduce Trinity, a memory-based distributed database and computation platform that supports online query processing and offline analytics on graphs. Trinity leverages graph access patterns in online and offline computation to optimize the use of main memory and communication in order to deliver the best performance. With Trinity, we can perform efficient graph analytics on web-scale, billion-node graphs using dozens of commodity machines, while existing platforms such as MapReduce and Pregel require hundreds of machines. In this paper, we analyze several typical and important graph applications, including search in a so- cial network, calculating Pagerank on a web graph, and sub-graph matching on web-scale graphs without using index, to demonstrate the strength of Trinity.
- Max de Marzi is lately my favorite source for graph data visualization posts
- Even if the diagram looks amazing I’m wondering if it would scale for larger data sets
- Even if I gave it some thought, I’m still not sure how graph databases can record historical relationship/the evolution of relationships in a graph. If you have any ideas I’d love to hear.
Original title and link: Neo4j and D3.js: Visualizing Connections Over Time ( ©myNoSQL)