1. Surrounded by Graphs
a short introduction to Graph Databases
and Neo4j
Created by , Neo Technology Inc.Julian Simpson
@builddoctor

2. Introduction: Who are you?
Yes, you!
0

3. Introduction: Who am I?
Dotbomb Solaris Admin
Reformed Java Build Monkey
DevOps Agitator
(Who actually went to DevOpsDays conference #1)
Full Stack Developer at Neo Technology, makers of Neo4j

4. Agenda: What's this talk about?
NoSQL Landscape
What are graphs, really?
Graph Examples
Neo4j Example and Story Time
Questions

5. Define NoSQL
(from: http://martinfowler.com/bliki/NosqlDe nition.html)
Not using the relational model (nor the SQL language)
Open source (mostly)
Designed to run on large clusters (mostly)
Based on the needs of 21st century web properties
No schema, allowing elds to be added to any record without controls

6. 4 kinds of NoSQL Database
Key-Value (e.g. BerkeleyDB, Redis)
Document (e.g. MongoDB, CouchDB)
Column Family (e.g. Cassandra, Vertica)
Graph (e.g. Neo4j, In niteGraph)
Most content stolen from NoSQL Distilled: A Brief Guide to the Emerging
World of Polyglot Persistence Paperback – August 18, 2012 by Pramod J.
Sadalage, Martin Fowler

7. Key Value
Definition
A simple hash table, primarily used when all access to
the database is via primary key
Example
<SEThobbit:name"baggins"
OK
<GEThobbit:name
"baggins"

8. Key Value
Use Cases
Recommended Not Recommended
Storing Session Information Relationships among data
User Pro les and Preferences Multi Operation Transactions
Shopping Cart Data Operations by Sets
Query by Data

9. Document Database
Definition
... documents are self-describing, hierarchical tree
data structures which can consist of maps, collections
and scalar values.
Example
{
"_id":1,
"name":{
"first":"Bilbo",
"last":"Baggins"
},
"comment":"Aren'twegladthishobbitbusinessisdone?"
}

10. Document Database
Use Cases
Recommended Not Recommended
Event Logging Complex Transactions spanning di erent
documents
Blogging, CMS
platforms
Queries against varying aggregate structure
Web or Real-Time
analytics
E-Commerce

11. Column Family Stores
Definition
... store data with keys mapped to values and the
values grouped into multiple column families, each
column family being a map of data
Example
{
"bilbo":{
age:"eleventysix",
surname:"baggins"
},
"frodo":{
nickname:"Mr.Frodo",
surname:"Baggins"
}

12. Column Family Stores
Use Cases
Recommended Not Recommended
Event Logging ACID Transactions
Content Management Systems, Blogging
platforms
Early Prototypes and
Spikes
Counters
Expiring Usage

13. Graph Databases
Definition
... store entities and relationships between those
entities.
Example
create(bilbo:Hobbit{name:'BilboBaggins'});
create(frodo:Hobbit{name:'FrodoBaggins'});
create(bilbo)-[:UNCLE_OF]->(frodo);

14. Graph Databases
Use Cases
Recommended Not Recommended
Connected Data Cases where you update all (or a
subset) of entities
Routing, Dispatch, Location
based services
(because Global Graph Operations)
Recommendation Engines
Fraud Detection

15. Chart or Graph?

16. Chart or Graph?
image: giphy.com

17. Chart or Graph?
From Ancient Greek su x -γραφω (-graphō), from
γράφω (gráphō, “to scratch, to scrape, to graze”),
from whence also -graphy.
Wiktionary

18. Chart or Graph?
Every invariant and covariant thus becomes
expressible by a graph precisely identical with a
Kekuléan diagram or chemicograph.
JJ Sylvester, 1878
image: Wikipedia

19. Graph all the bridges
image: Wikipedia

20. Graph all the bridges
image: Wikipedia

21. Graph all the things: Make
all:foobarbaz
bar:
touchbar
foo:bar
touchfoo
baz:bar
touchbaz

22. Graph all the things: Make
digraphG{
n3[label="all",color="red"];
n5[label="bar",color="red"];
n6[label="baz",color="red"];
n2[label="examples/Makefile",color="green"];
n4[label="foo",color="red"];
n5->n3;
n6->n3;
n4->n3;
n5->n6;
n5->n4;
}

23. Graph all the things: Make

24. Graph all the things: Maven

25. Graph all the things: Git

26. http://www.cse.scu.edu/
Graph all the things: Linux
image: http://www.cse.scu.edu/

27. Story Time
(a convoluted Neo4j Demo)

28. Cool story

29. Cool story
digraphBook{
page1[label="You'reOnConcorde"];
page1->page6;
page6[label="Youmeetaliens"];
page6->page3 [label="Demandtogohome"];
page6->page4 [label="BondwithU-TY"];
page3[label="You'refeelingsleepy"];
page3->page5 [label="Haveanap"];
page3->page16[label="StayAwake"];
page3->page8 [label="YoumeetIncu"];

30. Cool graph

31. Cypher Query Language
Declarative, like SQL
Allows query or update of the graph
Built on ASCII art
Named after a Matrix character

32. Cypher Query Language
CREATE (page1:Beginning:Page{number:1,synopsis:'YouareonConcorde,andsomethingcomestowards
(page6:Page{number:6,synopsis:'Youininacircularroom'}),
(page3:Page{number:3,synopsis:'Youareinanotherroomwithotherpeople. Youarefeelingsleep
(page4:Page{number:4,synopsis:'YouasktheU-TYmastersaboutthemselves.'}),
page1-[:TURNS_TO]->page6,
page6-[:TURNS_TO{decision:'DemandtobetakentoEarth'}]->page3,
page6-[:TURNS_TO{decision:'AsktheU-TYaboutthemselves'}]->page4,
(page5:Page {number:4,synopsis:'Thereisabandonyourhead'}),
(page8:Page {number:8,synopsis:'YoumeetIncu,captivefromAlara'}),
(page16:Page{number:16,synopsis:'YoumeetIngmar,theSwedishkidfrom1682'}),

33. How many pages are there?
MATCH(p:Page)
RETURNcount(p)asPages;
+-------+
| Pages |
+-------+
| 80 |
+-------+
1 row
238 ms

34. How many endings are there?
match(e:Ending)
returncount(e)asEndings;
+---------+
| Endings |
+---------+
| 27 |
+---------+
1 row
25 ms

35. How many Decisions?
match(p1)-[r:TURNS_TO]->(p2)
wherehas(r.decision)
returncount(r.decision)asDecisions;
+-----------+
| Decisions |
+-----------+
| 59 |
+-----------+
1 row
198 ms

36. How many paths through the
book?
match(b:Beginning)-[r:TURNS_TO*]-(e:Ending)
returncount(b)asPaths;
+-------+
| Paths |
+-------+
| 125 |
+-------+
1 row
250 ms

37. What's the shortest path?
match(b:Beginning)-[r:TURNS_TO*]-(e:Ending)
returnlength(r)asLength,e.synopsisasEnding
orderbylength(r)
limit1;
+------------------------------------+
| Length | Ending |
+------------------------------------+
| 4 | "You fall asleep forever" |
+------------------------------------+
1 row
88 ms

38. What's the longest path?
match(b:Beginning)-[r:TURNS_TO*]-(e:Ending)
returnlength(r)asLength,e.synopsisasEnding
orderbylength(r)desc
limit1;
+--------------------------------------------------------------------------------+
|Length|Ending |
+--------------------------------------------------------------------------------+
|19 |"YousendtheU-TYontheirway,feelingguiltaboutabandoningIncu"|
+--------------------------------------------------------------------------------+
1row
138ms

39. What's in the shortest path?
match(b:Beginning),(e:Ending),
path=shortestPath((b)-[*]-(e))
returnnodes(path);
+---------------------------------------------------------
| [Node[20]{number:1,synopsis:"You are on Concorde, and so
| [Node[20]{number:1,synopsis:"You are on Concorde, and so
| [Node[20]{number:1,synopsis:"You are on Concorde, and so

40. Wat? Oh.
match(b:Beginning),(e:Ending),
path=shortestPath((b)-[*]-(e))
returnnodes(path)asShortestPath
limit1;
+----------------------------------------------------------------------------------------------------------------------
|ShortestPath|
+----------------------------------------------------------------------------------------------------------------------
|[Node[20]{number:1,synopsis:"YouareonConcorde,andsomethingcomestowardsyou"},Node[21]{number:6,synopsis:"Youi
+----------------------------------------------------------------------------------------------------------------------

41. Where is Ultima?
match(p:Page)
wherep.synopsis=~'.*Ultima.*'
returnp;
+-------------------------------------------------------------------+
|p |
+-------------------------------------------------------------------+
|Node[98]{number:101,synopsis:"YouFindUltima! Itisparadise."}|
+-------------------------------------------------------------------+
1row
5ms

42. What links to Ultima?
matchpage-[:TURNS_TO]->(p:Page{number:101})
returnpage;
+------+
| page |
+------+
+------+
0 row
4 ms

43. Does anything link to it?
matchn-[*]-(p:Page{number:101})
returnn,p;
+----------------------------------------------------------------------------------------------------------------------------
---------------------------------+
|n |p
|
+----------------------------------------------------------------------------------------------------------------------------
---------------------------------+
|Node[2684]{number:104,synopsis:"Yournewfriendsletyouhangoutanytimeyoulike"}|Node[2683]{number:101,synopsis:"You
FindUltima! Itisparadise."}|
+----------------------------------------------------------------------------------------------------------------------------
---------------------------------+
1row
10ms

44. Ultima Visualized

45. About Neo4j
Drivers for Java, Ruby, Python, Scala, Perl, Clojure (and more)
GPL Community edition
AGPL Enterprise
Written in Java and Scala
Open sourced in 2007
https://github.com/neo4j/neo4j
http://neo4j.com

46. Thank you
Questions?
@neo4j
@builddoctor
image: memegenerator

47. Circular Dependencies
create (alice:Person {name:"Alice"})-[:LOVES]->
(bob:Person {name:"Bob"}),
(bob)-[:LOVES]->(carol:Person {name:"Carol"}),
(carol)-[:LOVES]->(alice)

48. Circular Dependencies
match (n)-[:LOVES]->(m) return n.name,m.name
+-------------------+
| n.name | m.name |
+-------------------+
| "Alice" | "Bob" |
| "Bob" | "Carol" |
| "Carol" | "Alice" |
+-------------------+
6 rows
39 ms