A graph is a data structure describing the real-world relationships among entities. A graph database management system (henceforth, a graph database) is then an online database management system in support of semantic operations based on the graph structure. It uses the vertex and edge to represent and store data, and supports CRUD operations.
Different from the traditional relational database management system (RDBMS, henceforth, a relational database), a graph database directly stores the relationships among entities, which in relational databases resort to expensive and time-consuming JOINs by way of foreign keys. When compared with the traditional tabular storage model, the graph data model provides a natural and hi-fi representation of complex real-word relationships.
The following figure describes relationships among entities like director, movie, actor/actress, movie genre, etc. using the graph database Galaxybase.
Regarding the storage model, traditional relational databases store and manage data in a tabular form consisting of rows and columns. Graph databases, on the other hand, are optimized and designed for efficient graph data store and queries, using vertices and edges as basic storage units. Typically accessed directly from an application, a graph database exposes a graph data model through CRUD operations. It is the equivalent of online transactional processing (OLTP) databases in the relational world.
In terms of the underlying storage, the graph database landscape can be divided into native and non-native. A native graph database stores data directly in the graph structure, while a non-native graph database serializes graph data into a relational database or some other type of database. Native graph databases are specially optimized and designed for storing and querying graph data, and therefore have better performance in deep-link queries.
Galaxybase graph database developed by CreateLink Tech. adopts a native distributed parallel framework. As its underlying storage and compute engine are both independently developed，and together with its remarkable scalability, Galaxybase is deeply optimized for efficient graph data store and processing at scale in the era of big data.