C++ (using files as database)

 http://www.cplusplus.com/doc/tutorial/files/

 https://code.sololearn.com/czgs0L9Om9WY/?ref=appt

 http://soprano.sourceforge.net/

 https://couchdb.apache.org/

 https://www.mongodb.com/

 https://study.com/academy/lesson/practice-using-files-as-databases-for-industry.html

 

 

 https://github.com/LEW21/sparqlxx

 sparqlxx

C++ semantic toolkit + sparqlite RDF database