Graph Databases

Chapter 5. Graphs in the Real World

In this chapter we look at some of the common real-world use cases for graph databases and identify the reasons why organizations choose to use a graph database rather than a relational or other NOSQL store. The bulk of the chapter comprises three in-depth use cases, with details of the relevant data models and queries. Each of these examples has been drawn from a real-world production system; the names, however, have been changed, and the technical details simplified where necessary to hide any accidental complexity, and thereby highlight key design points.

Why Organizations Choose Graph Databases

Throughout this book, we’ve sung the praises of the graph data model, its power and flexibility, and its innate expressiveness. When it comes to applying a graph database to a real-world problem, with real-world technical and business constraints, organizations choose graph databases for the following reasons:

“Minutes to milliseconds” performance

Query performance and responsiveness are top of many organizations’ concerns with regard to their data platforms. Online transactional systems, large web applications in particular, must respond to end users in milliseconds if they are to be successful. In the relational world, as an application’s dataset size grows, join pains begin to manifest themselves, and performance deteriorates. Using index-free adjacency, a graph database turns complex joins into fast graph traversals, thereby maintaining millisecond ...