creationsToRemove.add(creation);
subChangeIterator.remove();
} else if (ArrayUtil.containsAll(colNames1, colNames2)) {
// columns were added to the constraint
String[] addedColumns = diff(colNames2, colNames1);
changesToAdd.add(new ConstraintColumnsAddition(constraint1, addedColumns));
creationsToRemove.add(creation);
subChangeIterator.remove();
} else {
// the constraint is completely different - leave this as a pair of DELETION and CREATION
}