For PostgreSQL AGE add-on (AgensGraph-Extension) with the implementation of the query language for manipulating sets of interconnected hierarchical data that form a graph. Instead of columns and rows, graph-oriented databases use a structure similar to a network - nodes, their properties, and relationships between nodes are specified. AGE licensed under the Apache 2.0 license, donated by Bitnine under the auspices of the Apache Foundation, and currently hosted in the Apache Incubator.
The project continues the development of the DBMS , which a modification of PostgreSQL redesigned for graph processing. The key difference is the implementation of AGE in the form of a universal add-on that works as an add-on on regular releases of PostgreSQL. Issue published today supports PostgreSQL 11.
In the current state of AGE features of the Cypher query language, such as the use of the "CREATE" expression to determine nodes and links, the "MATCH" expression to search for data in a graph by specified conditions (WHERE), in the specified order (ORDER BY) and with restrictions (SKIP, LIMIT) . The result set returned by the query is defined using the "RETURN" expression. A "WITH" expression is available to chain multiple requests into a chain.
It is possible to create multi-model databases that combine models of hierarchical storage of properties in the form of a graph, a relational model and a model for storing documents in JSON format. It supports the execution of integrated queries that include elements of the SQL and Cypher languages.
It is possible to create indexes for properties of graph vertices and edges.
An extended set of Agtype types is proposed for use, including types for edges, vertices and paths in a graph. Aggregate expressions are not yet implemented. Available custom functions include id, start_id, end_id, type, properties, head, last, length, size, startNode, endNode, timestamp, toBoolean, toFloat, toInteger, and coalesce.
Source: opennet.ru