Database queries for retrieving data from database tables, that do not impose any constraints on the data to be retrieved, result in Cartesian product joins. Such unconstrained database queries when executed impose a significant load on resources, take a long time to execute, and may produce inaccurate and misleading results. Functionality can be implemented to reduce the amount of data retrieved by constraining database queries resulting in Cartesian product joins before they are executed. This can be done by leveraging referential constraints that depict relationships between the tables to be joined to limit the results produced by executing the Cartesian product join. Automatically detecting and preventing execution of Cartesian product joins by leveraging the referential constraints can reduce the processing load on the machine, reduce the time spent in executing the database query, minimize the number of query results, and prevent inaccurate results from being displayed.