GV$MAP_ELEMENT definition in Oracle Database 11.2
GV$MAP_ELEMENT
select
inst_id, -- INST_ID NUMBER
elem_name, -- ELEM_NAME VARCHAR2(256)
elem_idx, -- ELEM_IDX NUMBER
elem_cfgid, -- ELEM_CFGID VARCHAR2(256)
decode( -- ELEM_TYPE VARCHAR2(12)
elem_type,1,'MIRROR',2,'STRIPE',3,'RAID5', 4,'CONCATENATED',5,'PARTITION',6,'DISK',7,'ASMDISK',8,'NONE'),
to_number( -- ELEM_SIZE NUMBER
decode(elem_size,4294967295,NULL,elem_size)),
elem_nsubelem, -- ELEM_NSUBELEM NUMBER
elem_descr, -- ELEM_DESCR VARCHAR2(256)
stripe_size, -- STRIPE_SIZE NUMBER
to_number( -- LIB_IDX NUMBER
decode(lib_idx,4294967295,NULL,lib_idx))
from
x$ksfmelem