Graph Databases¶
Definition¶
A graph database is a databases whose specific purpose is the storage of
graph-oriented data structures. Thus it’s all about storing data as nodes and
edges.
By definition, a graph database is any storage solution where connected elements are linked together without using an index.
A graph database is a good fit for exploring data that are structured like a graph (or derived such as a tree), in particular when the relationships between items are significant. The ideal use case for a query, is starting from one or several nodes and traversing the graph.
Overview of the Different Platforms¶
Ranking Methodology :
The DB-Engines Ranking is a list of database management systems ranked by their current popularity. We measure the popularity of a system by using the following parameters:
Number of mentions of the system on websites measured as number of results in search engines queries. (Google, Bing and Yandex)
General interest in the system. Frequency of searches in Google Trends.
Frequency of technical discussions about the system. Number of related questions and the number of interested users on the well-known IT-related Q&A sites Stack Overflow and DBA Stack Exchange.
Number of job offers, in which the system is mentioned.
Number of profiles in professional networks, in which the system is mentioned (LinkedIn and Upwork).
Relevance in social networks. Number of Twitter tweets, in which the system is mentioned.
Neo4j Introduction¶
The Neo4j Graph Platform supports transactional processing and analytical processing of graph data.
It includes graph storage and graph computations. There is an extensive library
of graph models with a query language (Cypher)
The Neo4j Graph Algortihms Library has to be installed as a plug-in next to the database.
These algos are procedures that can be launched via the Cypher language.
Using Neo4j¶
A convenient way is to work with a local Neo4j database (download here). Another possibility is to use the sandbox-environment made available by Neo4j. On these sandboxes you will find plenty of ready to use examples.