Link parkin’: AgensGraph
AgensGraph is a new generation multi-model graph database for the modern complex data environment, which supports the relational and graph data models at the same time. AgensGraph supports ANSI-SQL and openCypher. SQL and Cypher can be integrated into single queries in AgensGraph.
AgensGraph is yet another PostgreSQL derivative. So at this point you could conceivably have one DB engine that has strong relational credibility, hardened geospatial functionality, support for time series via extension, semi-structured document data capabilities, and at least commercially developed graph data support.
Could this be the small to medium data management Rapture? Ha, ha! Only serious.