If it is supported in the JDBC interface of the database system, then two run-throughs are executed:
1st run - active: all constraints are enabled during the insertion process.
2nd run - inactive:: disabling all constraints (FK, PK and UK), inserting the rows into the database tables, reenabling the constraints.
Databases where this is not possible have the entry 'active - no choice^. The fastest run is displayed. Improvement then shows the ratio to the other run variant.
For MariaDB it means that the run with enabled constraints is 73.7% faster than the run with disabled constraints.
Hope this helps.