unt_write,  sum_number_of_bytes_write AS total_written, IFNULL(sum_number_of_bytes_write / NULLIF(count_write, 0), 0.00) AS avg_write, sum_number_of_bytes_read + sum_number_of_bytes_write AS total,  IFNULL(ROUND(100-((sum_number_of_bytes_read/ NULLIF((sum_number_of_bytes_read+sum_number_of_bytes_write), 0))*100), 2), 0.00) AS write_pct  FROM performance_schema.file_summary_by_instance ORDER BY sum_number_of_bytes_read + sum_number_of_bytes_write DESC;