Unified query engine for graph and relational data

A system comprising:

• a processor coupled to a memory, the memory having recorded thereon a computer program for querying by a query engine on a database having relational data and graph data that when executed by the processor causes the processor to be configured to:
• receive a query by the query engine, the query being in a language compatible with a first order logic paradigm,
• generate an intermediate representation (IR), the IR being compatible with a first order logic paradigm, and
• use the intermediate representation of the query for executing the query on the relational data and the graph data of the database.