Neo4j is a NoSQL database. It is quite scalable and schema-free.Neo4j is available in a GPL3-licensed open-source “community edition”, with online backup and high availability extensions licensed underneath a closed-source commercial license. Neo additionally licenses Neo4j with these extensions under closed-source commercial terms. It’s the world’s most famous graph database management system. Neo4j is developed by using Neo technology and known as an ACID-compliant transactional database with native graph storage and processing.
Neo4j is carried out in Java and available from software programs written in different languages the use of the Cypher query language via a transactional HTTP endpoint, or through the binary “bolt” protocol.
HOW NEO4J WORKS
Neo4j stores and displays information in the structure of the graph. In Neo4j, data is represented by means of nodes and relationships between these nodes.
Neo4j databases (as with any graph database) are a lot distinctive to relational databases such as MS Access, SQL Server, MySQL, etc. Relational databases use tables, rows, and columns to store data. They additionally existing data in a tabular fashion.
Neo4j does not use tables, rows, or columns to store or current data.
Neo4j is great for storing data that has many interconnecting relationships that’s why graph databases like Neo4j have a benefit and a lot higher at dealing with relational data than relational databases are. The format model would not generally require a predefined schema. So there is no need to create the database structure earlier than you load the information (like you do in a relational database). In Neo4j, the information is the structure. Neo4j is a “schema- optional” DBMS.
In Neo4j, no need to set up fundamental key/foreign key constraints to predetermine which fields can have a relationship, and to which data. You simply have to outline the relationships between the nodes you need.
FEATURES OF NEO4J
Distinguished Aspects Of Neo4j:
- Flexible Schema: Neo4j follows a data model known as graph model. The graph contains nodes and the nodes are linked to each other. Nodes and relationships store information in key-value pairs regarded as properties.
- ACID Property: Neo4j helps full ACID properties (Atomicity, Consistency, Isolation, and Durability).
- Scalability: Neo4j enables you to scale the database by way of increasing the number of reads/writes, and the volume besides affecting the data integrity and the speed of query processing.
- Reliability: Neo4j gives replication for data security and reliability.
- Cypher Query Language: Neo4j gives an effective declarative query language called Cypher Query language. It is used to create and retrieve relations between data besides the usage of the complex queries like Joins.
- Built-in Web applications: Neo4j additionally gives a built-in Neo4j browser internet application that can be used to create and retrieve your graph data.
- GraphDB: Neo4j follows the Property Graph Data Model.
- Drivers: Neo4j can work with −REST API to work with programming languages such as Java, Spring, Scala, etc.
- Java Script to work with UI MVC frameworks such as Node JS.
- It helps two types of Java API: Cypher API and Native Java API to enhance Java applications. In addition to these, you can also work with different databases such as MongoDB, Cassandra, etc.
- Indexing: Neo4j helps Indexes through the usage of Apache Lucence.
ADVANTAGES OF NEO4J
Most Essential Elements Of Neo4j:
- Highly scalable: Neo4j is distinctly scalable. It affords a simple, effective, and flexible facts model that can be modified in accordance with functions and uses. It provides:
Higher vertical scaling.
Improved operational characteristics at scale.
Higher concurrency.
Simplified tuning.
- Schema-free: Neo4j is schema-free like different NoSQL databases.
- High availability: Neo4j affords high availability for large organization real- time functions with transactional guarantees.
- Real-time data analysis: Neo4j affords results based totally on real-time data.
- Easy representation: Neo4j gives a very easy way to signify linked and semi-structured data.
- Fast Execution: Neo4j is fast due to the fact more related facts are very easy to retrieve and navigate.
- Easy retrieval: Neo4j enables you not only to signify but additionally without problems retrieve (traverse/navigate) linked information faster other databases comparatively.
- Cypher Query language: Neo4j affords CQL (Cypher Query Language) a declarative query language to represent the format visually, the usage of ASCII-art syntax. The commands of this language are very easy to analyze and human readable.
- No Join: Neo4j does not require complicated Joins to retrieve connected/related information as it is very effortless to retrieve its adjoining node or relationship details except
Joins or Indexes because it is a graph database and all nodes are already connected.
GRAPH DATABASE
A graph is a pictorial illustration of a set of objects where some pairs of objects are related through links. It is composed of two factors – nodes (vertices) and relationships (edges).
A graph database is a database used to model the data in the form of graph. Here, the nodes of a format depict the entities whilst the relationships depict the association of these nodes.
Popular Graph Databases
Neo4j is a famous Graph Database. Other Graph Databases are Oracle NoSQL Database, OrientDB, HypherGraphDB, GraphBase, InfiniteGraph, and AllegroGraph.
WHY GRAPH DATABASES
Nowadays, most of the information exists in the form of the relationship between different objects, and more often, the relationship between the information is more valuable than the information itself.
Relational databases save distinctly structured data that have quite a few documents storing the same kind of data so they can be used to store structured data and, they do not store the relationships between the data.
Unlike other databases, graph databases keep relationships and connections as first-class entities.
The data model for graph databases is less complicated compared to different databases and, they can be used with OLTP systems. They provide elements like transactional integrity and operational availability.
Popular Graph Databases
Neo4j is the most famous Graph Database. Other Graph Databases are
- Oracle NoSQL Database
- OrientDB
- HypherGraphDB
- GraphBase
- InfiniteGraph
- AllegroGraph etc.
NEO4J DATA MODEL
Neo4j Database follows the Property Graph Model for storing and managing its data. Neo4j is a graph database that includes the following aspects of the Property Graph Model.
The Graph model consists of Nodes, Relationships and Properties which specify data and its operation.
Properties are key-value pairs.
Nodes are represented the use of circle and Relationships are represented the usage of arrow keys. Relationship specifies the relation between two nodes.
There are two kinds of relationships between nodes in accordance to their directions: Unidirectional and Bidirectional
Each Relationship carries two nodes: “Start Node” or “From Node” and “To Node” or “End Node”.
Both Nodes and Relationships include properties.
Relationships ought to be directional in the Property Graph Data Model. If you create a relationship except a direction, it will through an error message.
There is three principal building block of a GraphDB Data model:
- Nodes
- Relationship
- Properties
Below is the simple instance of a Property Graph.
Property Graph
Here, we have represented Nodes the usage of Circles. Relationships are represented using Arrows. Relationships are directional. We can signify Node’s facts in terms of Properties (key-value pairs). In this example, we have represented each Node’s Id property within the Node’s Circle.
NODES: Nodes are frequently used to characterize entities. The simplest viable graph is a single node.
Consider the format below, consisting of a single node.
RELATIONSHIPS: A relationship connects two nodes. Relationships arrange nodes into structures, permitting a graph to resemble a list, a tree, a map, or a compound entity — any of which may additionally be combined into yet more complex, richly inter-connected structures.
PROPERTIES: Properties are name-value pairs that are used to add features to nodes and relationships.
In our example graphs, we have used the properties name and born on Person nodes, title and launched on Movie nodes, and the property roles on the : ACTED_IN relationship.
The price section of the property can preserve specific data kinds such as number, string, and Boolean
