A quick introduction to Graphs, Neo4j and neography.

1. Introducing Neo4j
Your Next Database
Max De Marzi

2. About Me
Built the Neography Gem (Ruby
Wrapper to the Neo4j REST API)
Playing with Neo4j since 10/2009
• My Blog: http://maxdemarzi.com
• Find me on Twitter: @maxdemarzi
• Email me: maxdemarzi@gmail.com
• GitHub: http://github.com/maxdemarzi

3. Agenda
• What is a Graph?
• What is a Graph Database?
• What can you do with a Graph Database?

4. What is a Graph?
• An abstract representation of a set of objects
where some pairs are connected by links.
Object (Vertex, Node)
Link (Edge, Arc, Relationship)

5. Different Kinds of Graphs
• Undirected Graph
• Directed Graph
• Pseudo Graph
• Multi Graph
• Hyper Graph

6. More Kinds of Graphs
• Weighted Graph
• Labeled Graph
• Property Graph

7. What is a Graph Database?
• A database with an explicit graph structure
• Each node knows its adjacent nodes
• As the number of nodes increases, the cost of
a local step (or hop) remains the same

8. Good For
• Highly connected data (social networks)
• Recommendations (e-commerce)
• Path Finding (how do I know you?)
• A* (Least Cost path)
• Data First Schema (bottom-up, but you still
need to design)

9. Not so good for
• Set Operations:
– Union
– Intersection
– Cross Joins
• Ginormous Amounts of Data
– Billions ok, Trillions not so much.

10. What is Neo4j?
• A Graph Database + Lucene Index
• Property Graph
• Full ACID (atomicity, consistency, isolation,
durability)
• High Availability (with Enterprise Edition)
• 32 Billion Nodes, 32 Billion Relationships,
64 Billion Properties
• Embedded Server
• REST API

11. Neo4j + Ruby

12. Neo4j Data Browser

13. Neo4j Console

14. Friends Graph Illustrated

15. Friends Graph

16. Relationships
.both is actually creating two relationships.
One incoming and one outgoing friends relationship.
Each Relationship in Neo4j only goes in one direction.

17. Friends of Friends

18. All Simple Paths
Simple paths means no loops allowed

19. Shortest Path

22. Cypher : Neo4j Query Language
ASCII ART FTW: a--b, a-->b, a<--c

24. Neoflix: Movie Recommender
http://neoflix.herokuapp.com/

25. http://getvouched.com

26. Neo4j and Heroku Challenge
http://neo4j-challenge.herokuapp.com/

27. Questions?
?

28. Thank you!
http://maxdemarzi.com