AgensGraph is a graph database built on top of PostgreSQL. The ability of PostgreSQL to handle with graph drive the AgensGraph's Team to develop a special index type to manage edges between nodes.
They also implemented the most part of the Cypher language and it is possible to write PL/Pgsql function with Cypher's query inside.
They also implemented the most part of the Cypher language and it is possible to write PL/Pgsql function with Cypher's query inside.
AgensGraph is Apache 2.0 licence.