GV$BLOCKING_QUIESCE definition in Oracle Database 11.2
GV$BLOCKING_QUIESCE
select
inst_id, -- INST_ID NUMBER
sid_kgskvft -- SID NUMBER
from
x$kgskvft
where
active_kgskvft = 1 and cg_name_kgskvft <> 'SYS_GROUP' and cg_name_kgskvft <> '_ORACLE_BACKGROUND_GROUP_'