Several weeks ago, on March 31, 2010, Twitter hosted a talk about Neo4j at the Twitter headquarters in San Francisco. If you are not familiar with Neo4J it is a database that stores data as a graph, with nodes, relationships (edges), and attributes (of the node). As far as I could glean from the presentation the graph is directed and can be weighted as well. From my perspective there are a few aspects of Neo4J that are quite impressive. First, the simplicity of the API let’s you get up and running in very little time. Next, the performance is quite remarkable with 1M nodes with each node having 50 connections, it takes only 2 milliseconds to find out if there is a path between two randomly chosen nodes. It also allows for transactions and rollbacks. More…