Graph Databases
Using Neo4J
2016-01-08
D Fetterman
What is a graph database?
- Relational datastore
- Can be schemaless
- Nodes
- Edges / Relationships
- Properties
Nodes
- Nouns
- Label(s) - optional
- Properties - Key:Value pairs
Person
ID: 100
Name: David
Gender: Male
Job: DBA
Person
ID: 101
Name: Eleanor
Gender: Female
Age: 1
Vehicle
ID: 102
Make: Honda
Model: Accord
Year: 2014
Employee
Relationships
- Verbs(?)
- Start and End node
- Directional
- Named
- Properties - optional
Person
ID: 100
Name: David
Vehicle
ID: 101
Make: Subaru
OWNS
ID: 102
Purchased: 2014
Why Graphs
- Performance
- Queries tend to be local
- Scales well compared to 'join-heavy' RDBMS data models
- Flexibility
- No enforced schemas
- Additive data model changes
- Fewer schema changes = lower maintenance
- Runtime schema changes?!
- Agility
- Data model in the code layer, not the datastore
- Exposed and testable API's
- Plays well in TDD
Interaction:
- neo4j-shell
-
web interface
- RESTful service
- REST::Neo4p
Examples
- Movie Graph
- CLI
- Web
- Perl