Oracle Message PLW-07206 - analysis suggests that the assignment to string may be unnecessary

ERRORanalysis suggests that the assignment to string may be unnecessary
CAUSEThis assignment may be unnecessary; the PL/SQL optimizer could not find any further use of the variable which was being set. If the assignment was being done for some side-effect such as raising a specific exception, the compiler may not have been able to understand the side-effect and this warning may be inappropriate.
ACTIONIf the assignment sets a variable whose value will not be used again and there are no side-effects (exceptions or calls) to consider, remove the assignment for better performance. If the assignment was in place to raise a specific known exception, replace the assignment with a RAISE statement.