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![Design Decisions
ASCII-art patterns
LOVES
A B
A -[:LOVES]-> B
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-19-2048.jpg)
![Design Decisions
Variable length paths
A B
A B
A B
...
A -[*]-> B
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-26-2048.jpg)
![Design Decisions
Optional relationships
A B
A -[?]-> B
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-28-2048.jpg)
![Design Decisions
Closures
start london = node(1), moscow = node(2)
match path = london -[*]-> moscow
where all(city in nodes(path) where city.capital = true)
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-29-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
return n
Parameters()
Nodes(n)
Extract([n])
ColumnFilter([n])
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-33-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
match n-[*]-> b
return n.name, n, count(*)
order by n.age
Parameters()
Nodes(n)
PatternMatch(n-[*]->b)
Extract([n.name, n])
EagerAggregation( keys: [n.name, n], aggregates: [count(*)])
Extract([n.age])
Sort(n.age ASC)
ColumnFilter([n.name,n,count(*)])
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-34-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
match n-[*]-> b
return n.name, n, count(*)
order by n.name
Parameters()
Nodes(n)
PatternMatch(n-[*]->b)
Extract([n.name, n])
Sort(n.name ASC,n ASC)
EagerAggregation( keys: [n.name, n], aggregates: [count(*)])
ColumnFilter([n.name,n,count(*)])
Wednesday, February 8, 2012](https://image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-35-2048.jpg)
![Design Decisions
ASCII-art patterns
LOVES
A B
A -[:LOVES]-> B
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-19-2048.jpg)
![Design Decisions
Variable length paths
A B
A B
A B
...
A -[*]-> B
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-26-2048.jpg)
![Design Decisions
Optional relationships
A B
A -[?]-> B
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-28-2048.jpg)
![Design Decisions
Closures
start london = node(1), moscow = node(2)
match path = london -[*]-> moscow
where all(city in nodes(path) where city.capital = true)
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-29-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
return n
Parameters()
Nodes(n)
Extract([n])
ColumnFilter([n])
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-33-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
match n-[*]-> b
return n.name, n, count(*)
order by n.age
Parameters()
Nodes(n)
PatternMatch(n-[*]->b)
Extract([n.name, n])
EagerAggregation( keys: [n.name, n], aggregates: [count(*)])
Extract([n.age])
Sort(n.age ASC)
ColumnFilter([n.name,n,count(*)])
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-34-2048.jpg)
![Implementation
Execution Plan
start n=node(0)
match n-[*]-> b
return n.name, n, count(*)
order by n.name
Parameters()
Nodes(n)
PatternMatch(n-[*]->b)
Extract([n.name, n])
Sort(n.name ASC,n ASC)
EagerAggregation( keys: [n.name, n], aggregates: [count(*)])
ColumnFilter([n.name,n,count(*)])
Wednesday, February 8, 2012](https://crownmelresort.com/image.slidesharecdn.com/cypher-120209041725-phpapp02/75/Cypher-Query-Language-35-2048.jpg)
Cypher Query Language
- 1. FOSDEM 2012 Graph Processing Room 5 Feb 2012 Cypher Query Language Andrés Taylor and Alistair Jones Wednesday, February 8, 2012
- 2. What is Cypher? • Graph Query Language for Neo4j • Aims to make querying simple Wednesday, February 8, 2012
- 3. Motivation Something new? • Existing Neo4j query mechanisms were not simple enough • Too verbose (Java API) • Too prescriptive (Gremlin) Wednesday, February 8, 2012
- 4. Motivation SQL? • Unable to express paths • these are crucial for graph-based reasoning • neo4j is schema/table free Wednesday, February 8, 2012
- 5. Motivation SPARQL? • SPARQL designed for a different data model • namespaces • properties as nodes Wednesday, February 8, 2012
- 6.
- 7. Design Decisions Declarative Imperative Declarative follow relationship specify starting point breadth-first vs depth-first specify desired outcome explicit algorithm algorithm adaptable based on query Wednesday, February 8, 2012
- 8. Design Decisions Pattern matching Wednesday, February 8, 2012
- 9. Design Decisions Pattern matching A B C Wednesday, February 8, 2012
- 10. Design Decisions A Pattern matching B C Wednesday, February 8, 2012
- 11. Design Decisions A Pattern matching B C Wednesday, February 8, 2012
- 12. Design Decisions A Pattern matching B C Wednesday, February 8, 2012
- 13. Design Decisions A Pattern matching B C Wednesday, February 8, 2012
- 14. Design Decisions ASCII-art patterns Wednesday, February 8, 2012
- 15. Design Decisions ASCII-art patterns () --> () Wednesday, February 8, 2012
- 16. Design Decisions ASCII-art patterns A B Wednesday, February 8, 2012
- 17. Design Decisions ASCII-art patterns A B (A) --> (B) Wednesday, February 8, 2012
- 18. Design Decisions ASCII-art patterns LOVES A B Wednesday, February 8, 2012
- 19. Design Decisions ASCII-art patterns LOVES A B A -[:LOVES]-> B Wednesday, February 8, 2012
- 20. Design Decisions ASCII-art patterns A B C Wednesday, February 8, 2012
- 21. Design Decisions ASCII-art patterns A B C A --> B --> C Wednesday, February 8, 2012
- 22. Design Decisions ASCII-art patterns A B C Wednesday, February 8, 2012
- 23. Design Decisions ASCII-art patterns A B C A --> B --> C, A --> C Wednesday, February 8, 2012
- 24. Design Decisions ASCII-art patterns A B C A --> B --> C, A --> C A --> B --> C <-- A Wednesday, February 8, 2012
- 25. Design Decisions Variable length paths A B A B A B ... Wednesday, February 8, 2012
- 26. Design Decisions Variable length paths A B A B A B ... A -[*]-> B Wednesday, February 8, 2012
- 27. Design Decisions Optional relationships A B Wednesday, February 8, 2012
- 28. Design Decisions Optional relationships A B A -[?]-> B Wednesday, February 8, 2012
- 29. Design Decisions Closures start london = node(1), moscow = node(2) match path = london -[*]-> moscow where all(city in nodes(path) where city.capital = true) Wednesday, February 8, 2012
- 30. Design Decisions Parsed, not an internal DSL Execution Semantics Serialisation Type System Portability Wednesday, February 8, 2012
- 31. Design Decisions Familiar for SQL users select start from match where where group by return order by Wednesday, February 8, 2012
- 32.
- 33. Implementation Execution Plan start n=node(0) return n Parameters() Nodes(n) Extract([n]) ColumnFilter([n]) Wednesday, February 8, 2012
- 34. Implementation Execution Plan start n=node(0) match n-[*]-> b return n.name, n, count(*) order by n.age Parameters() Nodes(n) PatternMatch(n-[*]->b) Extract([n.name, n]) EagerAggregation( keys: [n.name, n], aggregates: [count(*)]) Extract([n.age]) Sort(n.age ASC) ColumnFilter([n.name,n,count(*)]) Wednesday, February 8, 2012
- 35. Implementation Execution Plan start n=node(0) match n-[*]-> b return n.name, n, count(*) order by n.name Parameters() Nodes(n) PatternMatch(n-[*]->b) Extract([n.name, n]) Sort(n.name ASC,n ASC) EagerAggregation( keys: [n.name, n], aggregates: [count(*)]) ColumnFilter([n.name,n,count(*)]) Wednesday, February 8, 2012
- 36. Thanks for Listening! Questions? Andrés Taylor andres.taylor@neotechnology.com @andres_taylor Alistair Jones alistair.jones@neotechnology.com @apcj Wednesday, February 8, 2012