A seminar on neo4 j

WelcomeSchool of Engineering, CUSAT 1

A SEMINAR ON

NEO4J

Presented by: Vishnu Sanker

Project guide: Dr. Sudheep Elayidom

Contents

• Trends in big data

• NoSQL

• Graphs

• Neo4j

• Brief introduction to Cypher

• Pros and Cons of Neo4j

School of Engineering, CUSAT 3

TRENDS IN BIG DATA

1. Increasing data size (big data)

• “Every 2 days we create as much information as we did up to 2003”

- Eric Schmidt

2. Increasingly connected data (graph data)

• For example, text documents to html

3. Semi-structured data

• Individualization of data, with common sub-set

4. Architecture

• From monolithic to modular, distributed applications


NO SQL


NOSQL

• Carlo Strozzi used the term NoSQL in 1998 to name his lightweight,

open-source relational database that did not expose the standard

SQL interface

• Provides a mechanism for storage and retrieval of data that is

modeled in means other than the tabular relations used in relational

databases.


BENEFITS OF NOSQL

• Large volumes of structured, semi-structured and unstructured data

• Agile sprints, quick iteration, and frequent code pushes

• Flexible, easy to use object-oriented programming

• Efficient, scale-out architecture instead of expensive, monolithic architecture


TYPES OF NOSQL

• Column

- distributed data store is a NoSQL object of the lowest level in a keyspace. It is a tuple (a key-value pair) consisting of three elements

Unique name : Used to reference the column

Value : The content of the column.

Timestamp : Used to determine the valid content

• Document oriented

- designed for storing, retrieving, and managing document-oriented information, also known as semi-structured data

• Key value pairs

- collection of key value pairs

• Graph

- database that uses graph structures with nodes, edges, and properties to represent and store data


GRAPHS


GRAPHS

A GRAPH DATABASE...

NO: not for charts & diagrams, or vector artwork

YES: for storing data that is structured as a graph


Graphs Everywhere

๏Relationships in

•Politics, Economics, History, Science, Transportation

๏Biology, Chemistry, Physics, Sociology

•Body, Ecosphere, Reaction, Interactions

๏Internet

•Hardware, Software, Interaction

๏Social Networks

•Family, Friends

•Work, Communities

•Neighbours, Cities, Society



Good Relationships

๏The world is rich, messy and related data

๏Relationships are as least as important as the things they connect

๏Complex interactions

๏Always changing, change of structures as well

๏Graph: Relationships are part of the data

๏RDBMS: Relationships part of the fixed schema


HOW AN RDB IS REPRESENTED BY GRAPH

RDB PROPERTY GRAPH


NEO4J - A GRAPH DATABASE

NEO4j - A GRAPH DATABASE


GRAPHS



Neo4j is a Graph Database

๏A Graph Database:

•a schema-free Property Graph

•perfect for complex, highly connected data

๏Why NEO4J:

•reliable with real ACID Transactions

•fast with more than 1M traversals / second

•Server with REST API, or Embeddable on the JVM

•scale out for higher-performance reads with High-Availability


DATA MODELING FOR NEO4J









SAMPLE CODE



CYPHER


CYPHER - QUERY LANGUAGE FOR NEO4J

• Declarative query language

• Describe what you want, not how

• Based on pattern matching

• declarative grammar with clauses (like SQL)

• aggregation, ordering, limits

• create, update, delete


Cypher: START + RETURN

๏START <lookup> RETURN <expressions>

๏START binds terms using simple look-up

•directly using known ids

•or based on indexed Property

๏RETURN expressions specify result set


Cypher: MATCH

๏START <lookup> MATCH <pattern> RETURN <expr>

๏MATCH describes a pattern of nodes+relationships

•node terms in optional parenthesis

•lines with arrows for relationships


Cypher: WHERE

๏START <lookup> [MATCH <pattern>]

๏WHERE <condition> RETURN <expr>

๏WHERE filters nodes or relationships

•uses expressions to constrain elements


Cypher: SET

๏SET [<node property>] [<relationship property>]

•update a property on a node or relationship

•must follow a START


Cypher: DELETE

๏DELETE [<node>|<relationship>|<property>]

•delete a node, relationship or property

•must follow a START

•to delete a node, all relationships must be deleted

first


PROS AND CONS OF NEO4J

PROS

• Powerful data model - as generalized as rdbms

• Connected data is locally indexed

• Easy to query

Cons

• Sharding

• Needs new way of thinking


Concluding...

• Neo4j is property graph database

• It is scalable, flexible, and is totally

designed in java

• Cypher is a query language for neo4j,

which is highly declarative and flexible

aswell


