I’m not sure whether it is possible to split a report output in more than one file, but I guess the answer is no.
I think you could implement some kind of pagination to split the report in many files.
You could do it by modifying the report’s query to receive the record numbers to include as parameters.
Using ROWNUM, the query should look something like this:
SELECT * from (SELECT ID, first_name, salary,rownum rnum
WHERE rownum <= :your_highest_record_number
ORDER BY salary
WHERE rnum >= :your_lowest_record_number ;
Or you could achieve something similar using the ROW_NUMBER() analytical function.
These pagination queries will not perform very fast, but in some circumstances they are the only choice.
You might want to have a look at these Oracle pagination tips