GV$IOFUNCMETRIC definition in Oracle Database 11.2
GV$IOFUNCMETRIC
SELECT
inst_id, -- INST_ID NUMBER
begtime, -- BEGIN_TIME DATE
endtime, -- END_TIME DATE
intsize_csec, -- INTSIZE_CSEC NUMBER
f.function_id, -- FUNCTION_ID NUMBER
fn.function_name, -- FUNCTION_NAME VARCHAR2(18)
small_read_mbps, -- SMALL_READ_MBPS NUMBER
small_write_mbps, -- SMALL_WRITE_MBPS NUMBER
large_read_mbps, -- LARGE_READ_MBPS NUMBER
large_write_mbps, -- LARGE_WRITE_MBPS NUMBER
small_read_iops, -- SMALL_READ_IOPS NUMBER
small_write_iops, -- SMALL_WRITE_IOPS NUMBER
large_read_iops, -- LARGE_READ_IOPS NUMBER
large_write_iops, -- LARGE_WRITE_IOPS NUMBER
decode( -- AVG_WAIT_TIME NUMBER
num_waits, 0, 0, wait_time / num_waits)
FROM
x$kewmiofmv f,
(
select
function_id,
function_name
from
v$iostat_function
group by
function_id,
function_name) fn
WHERE
flag1 = 1 AND f.function_id = fn.function_id