For PostgreSQL the AGE (AgensGraph-Extension) plugin with a query language implementation for manipulating sets of interconnected hierarchical data that form a graph. Instead of columns and rows, graph-oriented databases use a structure resembling a network — defining nodes, their properties, and relationships between nodes. AGE is licensed under Apache 2.0, transferred by Bitnine under the auspices of the Apache Foundation and is currently in the Apache incubator.
The project continues the development of the DBMS , which a modified version of PostgreSQL optimized for graph processing. The key difference is the implementation of AGE as a universal plugin, functioning as an addon over standard PostgreSQL releases. The recently released supports operation with PostgreSQL 11.
In its current state, AGE offers query language capabilities such as the use of the 'CREATE' expression to define nodes and edges, the 'MATCH' expression to search data in the graph based on specified conditions (WHERE), in a given order (ORDER BY) and with set limits (SKIP, LIMIT). The resulting dataset returned by the query is specified using the 'RETURN' expression. The 'WITH' expression is available for chaining multiple queries.
It is possible to create multimodal databases that combine models for hierarchical property storage in the form of a graph, relational models, and document storage in JSON format. Integration queries combining elements of SQL and Cypher languages are supported.
Index creation is available for properties of graph nodes and edges.
For use, an extended set of Agtype types has been proposed, including types for edges, nodes, and paths in the graph. Aggregate expressions are not yet implemented. Among the available specialized functions are: id, start_id, end_id, type, properties, head, last, length, size, startNode, endNode, timestamp, toBoolean, toFloat, toInteger, and coalesce.
Source: opennet.ru
