GV$WAITCLASSMETRIC definition in Oracle Database 11.2
GV$WAITCLASSMETRIC
SELECT
inst_id, -- INST_ID NUMBER
begtime, -- BEGIN_TIME DATE
endtime, -- END_TIME DATE
intsize_csec, -- INTSIZE_CSEC NUMBER
wait#, -- WAIT_CLASS# NUMBER
wait_id, -- WAIT_CLASS_ID NUMBER
average_waiter_count, -- AVERAGE_WAITER_COUNT NUMBER
dbtime_in_wait, -- DBTIME_IN_WAIT NUMBER
time_waited, -- TIME_WAITED NUMBER
wait_count, -- WAIT_COUNT NUMBER
time_waited_fg, -- TIME_WAITED_FG NUMBER
wait_count_fg -- WAIT_COUNT_FG NUMBER
FROM
x$kewmevmv
WHERE
flag1 = 1 AND GROUPID = 1