1

Graph databases:time for serious stuff

David FunaroAlessandro Nadalin

Agenda

2

•Theory•When to use a graph?•Why graphDB?•The graphDB community•OrientDB•Orient PHP library

Essential (Theory)

A

3

Ver

tex

(V,G

raph

G =

Edg

e

E)

Binary Relation

4

BA

Hates

Itchy Scratchy

Binary Relation

4

B

Vertex Vertex

Edge

A

Graph

5

B

D

E

G

FA

Undirected Graph

B

D

E

F

A

Example: Friendship 6

Directed Edge

7

B

Vertex Vertex

Edge

A

Directed Graph

8Example: Followee

D

FA

BA

Path

9

B

D

E

G

FA

Path

10

B D EG FA

Graph -> GraphDB

11

A GraphDB is a database that use the graph as its primary data structure

... when to use a graph ?

Recommendations

14

John

Rome

Milan

Cinema A

Cinema B

Cinema C

Se7en

Mr Bean

Thriller

Fun

lives in

location

location

location

type

type

likes

shows

shows

shows

Recommendations

22

John

Rome

Milan

Cinema A

Cinema B

Cinema C

Se7en

Mr Bean

Thriller

Fun

lives in

location

location

location

type

type

likes

shows

shows

shows x

✓

x

x x x ✓ ✓ ✓ ✓

Your data is a graph

23

a tree is a graph

24

parent_id is a graph

25

Solve decision problems

Maximum flow

maximum flowGiven a dataset, calculate how to best organize it

travelling salesman problem

The pizza guy needs to deliver on A, B,C.

Decision base on distance, traffic, time and so on.

Shortest path

Identify "special" nodes of the graph

Given your dataset, organize some clusters

Are there some nodes which cannot belong to a cluster?

They probably have some properties different from the average

Given your dataset, organize some clusters

Are there some nodes which cannot belong to a cluster?

They probably have some properties different from the average

ACHTUNG!TERRORISTEN!

but ... why graphDB?

36

✓Relational Database

(mysql, oracle)

✓Document Oriented DB

(mongodb, couchdb)

✓XML Database

(MarkLogic, eXist-db)

http://www.slideshare.net/slidarko/problemsolving-using-graph-traversals-searching-scoring-ranking-and-recommendation#

Representing a Graph in:

37

where is the difference ?

38

A graph database is any storage system that provides index-free adjacency.

GraphDB

http://www.slideshare.net/slidarko/problemsolving-using-graph-traversals-searching-scoring-ranking-and-recommendation

Step by step example

40

Given a list of people, find their homepages

Tree-based DB WAY

41

1

find

http://davidfunaro.com

3

David Funaro

put in the Search Engine2

Tree-based DB WAY

41

1

find

http://davidfunaro.com

3

David Funaro

put in the Search Engine2

The cost to find a single friend HP grows as the friends HP tables grows

GraphDB WAY

42

get the embedded information(index)

www.odino.org

1

it’s like that the GraphDB has an additional information(the ancor <a>)

GraphDB WAY

43

<a href=”http://odino.org”>Alessandro Nadalin

</a>

The Anchor work as a local index to reach the document = index-free

adjacency

Local cost

44

The local cost is O(k) = Constant

Local cost

45

The local cost is O(k) = Constant

Local cost

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Thus, as the graph grows in size, the cost of a local step remain the same

any database can implicity represent a graph

BUTonly a graph database make the graph

structure explicit

47

Benchmark

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• 1 Million Vertex

• 4 Million Edge

• Scale Free Tolopogy

• MySql VS Neo4J

• Both Hash and BTree

Deph RDBMS Graph

1

2

3

4

5

100ms 30ms

1000ms 500ms

10000ms 3000ms

100000ms

50000ms

N/A 100000ms

http://markorodriguez.com/2011/02/18/mysql-vs-neo4j-on-a-large-scale-graph-traversal/

How ?

49

PREFIX geospecies: <http://rdf.geospecies.org/ont/geospecies#>PREFIX lycopodiophyta: <http://lod.geospecies.org/phyla/Pc2>PREFIX door_county: <http://sws.geonames.org/5250768/>PREFIX dcterms: <http://purl.org/dc/terms/>

SELECT DISTINCT ?family_name ?canonicalName ?commonName ?identifier ?wikipedia_url

WHERE {?x geospecies:hasFamilyName ?family_name; geospecies:hasCanonicalName ?canonicalName; geospecies:hasCommonName ?commonName; dcterms:identifier ?identifier; geospecies:inPhylum lycopodiophyta:; geospecies:isUSDA_ExpectedIn door_county:. OPTIONAL { ?x geospecies:hasCommonName ?commonName; geospecies:hasWikipediaArticle ?wikipedia_url} }

ORDER BY ?family_name ?canonicalName

50

http://blog.acaro.org/entry/somebody-is-going-to-hate-me-nosparql

NoSPARQL

Databases

community that is building and feeding the GraphDB ecosystem

ThinkerPopStack

NoSPARQL

Blueprints is a collection of interfaces, implementations, ouplementations, and test suites for the property graph data

model. Blueprints is analogous to the JDBC, but for graph databases.

https://github.com/tinkerpop/blueprints/wiki/

data model and their implementation

provide a collection of "pipes" that are connected togheter to from processing

pipelines

a data flow Framework using Process Graph

a graph-based programming language.

a Turing-Complete graph-base programming language that compiles Gremlin syntax down to Pipes

a REST-full graph shell.

Allow blueprints graph to be exposed through a RESTful API (HTTP)

What's hot

OrientDB

Glossary

59

<10:05>RID

Cluster Position

CLASS

Main features

Inheritance

class Bike

class Vehicle

class Car

class Bike

class Vehicle

class Car

SELECT FROM Vehicle WHERE owner = 1:1

class Bike

class Vehicle

class Car

can return records of class Bike or Car

Traversal

68SELECT FROM fellas WHERE any() traverse(0,-1) ( @rid = [Michelle @rid] )

SELECT FROM fellas WHERE any() traverse(0,2) ( @rid = [Michelle @rid] )

SQL synthax

beyond SQL

SELECT FROM authors WHERE book.title = ...

ACID

speaks JSON

{ "schema": { "name": "Address" }, "result": [{ "@type": "d", "@rid": "#13:0", "@version": 6, "@class": "Address", "type": "Residence", "street": "Piazza Navona, 1", "city": "#14:0", "nick": "Luca2" }, { ... ...

Double Protocol

HTTP

Universal

HTTP

Easy to interact with

Blazing fast

binary

on-record SELECTs

SELECT FROM cats

SELECT FROM 11:0

SELECT FROM [11:0,11:1]

SELECT FROM [11:0,12:0]

stress-free setup

2 Mb

./orient/bin/server.sh

94

in-memory DB

or disk-persisted

Supports standards Supports standards

97

OrientDB

•Inheritance

•Traversal

•SQL-like syntax

•ACID

•Speak JSON

•Double protocol

•on-record Select

•ThinkerPop Compliant

Language Bindings

99http://code.google.com/p/orient/wiki/ProgrammingLanguageBindings

Orient = PHP Library to work with OrientDB

101

https://github.com/congow/Orient

Data Mapper

Query BuilderHTTP Binding

HTTP Binding

use Congow\Orient;use Congow\Orient\Foundation\Binding;

$driver   = new Orient\Http\Client\Curl();$orient   = new Binding($driver, '127.0.0.1', '2480', 'admin', 'admin', 'demo');

$response = $orient->query("SELECT FROM Address");

$output   = json_decode($response->getBody());

foreach ($output->result as $address){  var_dump($address->street);}

apart from ->query($SQL)

->get|delete|postClass($class)

->post|delete|put|getDocument($rid)

...and much more!

(connect, disconnect, ...)

Query Builder

use Congow\Orient\Query;

$query = new Query();$query->from(array('users'))->where('username = ?', "admin");

echo $query->getRaw(); // SELECT FROM users WHERE username = "admin"

               $query->select(array('name', 'username', 'email'), false)                ->from(array('12:0', '12:1'), false)                ->where('any() traverse ( any() like "%danger%" )')                ->orWhere("1 = ?", 1)                ->andWhere("links = ?", 1)                ->limit(20)                ->orderBy('username')                ->orderBy('name', true, true)                ->range("12:0", "12:1");

              SELECT name, username, email               FROM [12:0, 12:1]               WHERE any() traverse ( any() like "%danger%" )              OR 1 = "1" AND links = "1"               ORDER BY name, username               LIMIT 20               RANGE 12:0 12:1

Data Mapper

namespace Poland\PHPCon\Entity;

use Congow\Orient\ODM\Mapper\Annotations as ODM;

/*** @ODM\Document(class="Person")*/class Speaker{    /**     * @ODM\Property( type="string")     */    protected $name;

    public function setName($name)    {        $this->name = $name;    }

Domain Driven Design

{ "schema": { "name": "Speaker" }, "result": [{ "@type": "d", "@rid": "#1:0", "@version": 6, "@class": "Speaker", "name": "David Coallier" }, { ... ...

{ "schema": { "name": "Speaker" }, "result": [{ "@type": "d", "@rid": "#1:0", "@version": 6, "@class": "Speaker", "name": "David Coallier" }, { ... ...

$david = $mapper->hydrate(json_decode($speaker));

{ "schema": { "name": "Speaker" }, "result": [{ "@type": "d", "@rid": "#1:0", "@version": 6, "@class": "Speaker", "name": "Martin Fowler" }, { ... ...

$david instanceOf Poland\PHPCon\Entity\Speaker

Repository Pattern

$repo = $manager->getRepository('Speaker')

$speakers = $repo->findAll();

$speaker = $repo->find($rid);

$criteria = array('Name' => 'Martin');

$lornas = $repo->findBy($criteria);

$criteria = array( 'Name' => 'Martin', 'last_name' => 'Fowler');

$lornaJ = $repo->findOneBy($criteria);

https://github.com/doctrine/common/tree/master/lib/Doctrine/Common/Persistence

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David Funaro@ingdavidinohttp://davidfunaro.com

Alessandro Nadalin@_odino_

http://odino.org

That’s all, folks!

Credits

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