Emil Eifrem, founder of Neo4j has written an article for Mashable about the rise of graph databases. He writes, "Until the NOSQL wave hit a few years ago, the least fun part of a project was dealing with its database. Now there are new technologies to keep the adventuresome developer busy. The catch is, most of these post-relational databases, such as MongoDB, Cassandra, and Riak, are designed to handle simple data. However, the most interesting applications deal with a complex, connected world. A new type of database significantly changes the standard direction taken by NOSQL. Graph databases, unlike their NOSQL and relational brethren, are designed for lightning-fast access to complex data found in social networks, recommendation engines and networked systems."
He continues, "Pancake, for example, which is Mozilla’s next-generation browser project, uses a graph database to store browsing history in the cloud, since the web is just one big graph. Graph theory dates back to 1735, when Leonard Euler solved the Seven Bridges of Königsberg problem by devising a topology consisting of nodes and relationships to answer the then-famous question, 'Is it possible to trace a walk through the city that crosses every bridge just once?' Graph theory has since found many uses, but only recently has it been applied to storing and managing data. It turns out that graphs are a very intuitive way to represent relationships between data."
Image: Courtesy Neo4j