Use Neo4j In Your Next Java Project
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This document discusses using Neo4j graph databases for projects instead of traditional SQL databases. It notes that graph databases better model complex relationships, scale to large amounts of data more efficiently, and allow for faster querying of connected data through graph traversal compared to SQL databases which require complex joins. Examples are provided showing how queries involving friends of friends or finding connection paths between characters can be done more simply and quickly using the Cypher query language in Neo4j compared to equivalent SQL queries. A demo is also promised to illustrate these benefits hands-on.
![MATCH
(c:Character)-[:MEMBER_OF]->(t:Team)
WHERE t.name = 'Avengers'
RETURN c.name
Cypher Intro](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-13-320.jpg)
![MATCH (deadpool:Character)-[:FRIEND_OF*2]->(FriendOfFriend)
WHERE deadpool.name = 'Deadpool'
AND NOT (deadpool)-[:FRIEND_OF]->(FriendOfFriend)
AND NOT deadpool = FriendOfFriend
RETURN FriendOfFriend.name, COUNT(*)
ORDER BY COUNT(*) DESC, FriendOfFriend.name
Sooo Many Joins](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-19-320.jpg)
![MATCH (deadpool:Character)-[:FRIEND_OF*2]->(FriendOfFriend)
Sooo Many Joins
FROM MarvelCharacter deadpool
INNER JOIN Friends DeadpoolFriends
ON deadpool.Id = DeadpoolFriends.CharacterId1
INNER JOIN Friends FriendsFriends
ON DeadpoolFriends.CharacterId2 = FriendsFriends.CharacterId1
INNER JOIN MarvelCharacter FriendOfFriend
ON FriendsFriends.CharacterId2 = FriendOfFriend.Id](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-20-320.jpg)
![MATCH (deadpool:Character { name:"Deadpool" }),
(other:Character { name:"Ultron" }),
path = shortestPath((deadpool)-[*]-(other))
RETURN path
Shortest Path](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-23-320.jpg)
![MATCH (deadpool:Character { name:"Deadpool" }),
(other:Character { name:"Ultron" }),
path = shortestPath((deadpool)-[*]-(other))
RETURN path
Shortest Path](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-24-320.jpg)
![MATCH (deadpool:Character { name:"Deadpool" }),
(other:Character { name:"Ultron" }),
path = shortestPath((deadpool)-[*]-(other))
RETURN path
Shortest Path](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-25-320.jpg)
![MATCH (deadpool:Character { name:"Deadpool" }),
(other:Character { name:"Ultron" }),
path = shortestPath((deadpool)-[*]-(other))
RETURN path
Shortest Path](https://image.slidesharecdn.com/neo4j-icjrev-160722072537/85/Use-Neo4j-In-Your-Next-Java-Project-26-320.jpg)
Use Neo4j In Your Next Java Project
- 1. Use Neo4j In Your Next Java Project Love relationships again Tobias Coetzee @tobiascode
- 2. All Roads Lead To SQL Do we even have other choices? Every project we work on will have some form of database, 99% of those in the enterprise will be a relational database
- 3. Impedance Mismatch The database model does not match the domain model Not Scaling More data means less speed Complex Queries Lots of joins and some self joining nightmares as a bonus Relationship Problems
- 5. Queries with lots of joins to get to the final answer Similar Data Models Configuration Security Navigation
- 6. Graph Databases Just Mathematics Based on graph theory, created by Leonhard Euler All About Relationships In graph databases relationships are first class citizens Neo4j Most well known and widely used graph database
- 7. Graph Databases Nodes Represent the entities or records in the database Relationships Link nodes together Properties Nodes and relationships can also have properties
- 8. MEMBER_OF MEMBER_OF FRIEND_OF WAS_IN TOOK_PART_IN • Eyes: Blue • Hair: None • Citizenship: Canada• Since: 14 Feb 2001 Graph Databases
- 9. The database model does not match the domain model Impedance Mismatch
- 11. Traditional Solutions ORM Frameworks, e.g. Hibernate or Spring Data Boilerplate code generation tools Impedance Mismatch
- 13. MATCH (c:Character)-[:MEMBER_OF]->(t:Team) WHERE t.name = 'Avengers' RETURN c.name Cypher Intro
- 14. Demo Time
- 15. Lots of joins and some self joining nightmares as a bonus Complex Queries
- 16. Denormalise the database Hide complexity behind views and stored procedures Traditional Solutions Complex Queries
- 17. Friends of Friends Name Number Friends in Common Vision 51 Wolfsbane 38 Punisher 33 Rage 38 Shard 25 Wind Dancer 25 Possible friend recommendations for Deadpool
- 18. SELECT FriendOfFriend.Name, COUNT(*) FROM MarvelCharacter deadpool INNER JOIN Friends DeadpoolFriends ON deadpool.Id = DeadpoolFriends.CharacterId1 INNER JOIN Friends FriendsFriends ON DeadpoolFriends.CharacterId2 = FriendsFriends.CharacterId1 INNER JOIN MarvelCharacter FriendOfFriend ON FriendsFriends.CharacterId2 = FriendOfFriend.Id WHERE deadpool.Name = 'Deadpool' AND FriendsFriends.CharacterId2 NOT IN( SELECT CharacterId2 FROM MarvelCharacter INNER JOIN Friends ON MarvelCharacter.Id = CharacterId1 WHERE Name = 'Deadpool') GROUP BY FriendOfFriend.Name ORDER BY COUNT(*) DESC Sooo Many Joins
- 19. MATCH (deadpool:Character)-[:FRIEND_OF*2]->(FriendOfFriend) WHERE deadpool.name = 'Deadpool' AND NOT (deadpool)-[:FRIEND_OF]->(FriendOfFriend) AND NOT deadpool = FriendOfFriend RETURN FriendOfFriend.name, COUNT(*) ORDER BY COUNT(*) DESC, FriendOfFriend.name Sooo Many Joins
- 20. MATCH (deadpool:Character)-[:FRIEND_OF*2]->(FriendOfFriend) Sooo Many Joins FROM MarvelCharacter deadpool INNER JOIN Friends DeadpoolFriends ON deadpool.Id = DeadpoolFriends.CharacterId1 INNER JOIN Friends FriendsFriends ON DeadpoolFriends.CharacterId2 = FriendsFriends.CharacterId1 INNER JOIN MarvelCharacter FriendOfFriend ON FriendsFriends.CharacterId2 = FriendOfFriend.Id
- 21. Quick Demo
- 22. How Do You Know Him? MEMBER_OF MEMBER_OF FRIEND_OF How can Deadpool connect to Ironman?
- 23. MATCH (deadpool:Character { name:"Deadpool" }), (other:Character { name:"Ultron" }), path = shortestPath((deadpool)-[*]-(other)) RETURN path Shortest Path
- 24. MATCH (deadpool:Character { name:"Deadpool" }), (other:Character { name:"Ultron" }), path = shortestPath((deadpool)-[*]-(other)) RETURN path Shortest Path
- 25. MATCH (deadpool:Character { name:"Deadpool" }), (other:Character { name:"Ultron" }), path = shortestPath((deadpool)-[*]-(other)) RETURN path Shortest Path
- 26. MATCH (deadpool:Character { name:"Deadpool" }), (other:Character { name:"Ultron" }), path = shortestPath((deadpool)-[*]-(other)) RETURN path Shortest Path
- 27. Quick Demo
- 28. Not Scaling More data means less speed
- 29. Traditional Solutions Offline databases Batch runs to process data More indexes Not Scaling
- 30. Speed Embedded Server Processing requires reading the same data you wrote Fixed Size Records All records of the same type have the same size on disk Index-Free Adjacency Pointer to the next node
- 31. Demo Time
- 32. Wrong Usage This is not a hammer
- 33. Wrong Usage Set Orientated Lists of things with few or no joins Global Operations Made for local graph operations Aggregate Queries Processing requires reading the same data you wrote
- 34. Thank You For Staying Till The End! @tobiascode