GV$DB_CACHE_ADVICE definition in Oracle Database 11.2
GV$DB_CACHE_ADVICE
select
A.inst_id, -- INST_ID NUMBER
A.bpid, -- ID NUMBER
B.bp_name, -- NAME VARCHAR2(20)
A.blksz, -- BLOCK_SIZE NUMBER
decode ( -- ADVICE_STATUS VARCHAR2(3)
A.status, 2, 'ON', 'OFF'),
A.poolsz, -- SIZE_FOR_ESTIMATE NUMBER
round((A.poolsz / A.actual_poolsz), 4), -- SIZE_FACTOR NUMBER
A.nbufs, -- BUFFERS_FOR_ESTIMATE NUMBER
decode ( -- ESTD_PHYSICAL_READ_FACTOR NUMBER
A.base_preads, 0, to_number(null), round((A.preads / A.base_preads), 4)),
decode ( -- ESTD_PHYSICAL_READS NUMBER
A.base_preads, 0, A.actual_preads, round((A.preads * (A.actual_preads / A.base_preads)), 0)),
A.estd_time_for_disk_reads, -- ESTD_PHYSICAL_READ_TIME NUMBER
decode ( -- ESTD_PCT_OF_DB_TIME_FOR_READS NUMBER
A.total_db_time, 0, A.estd_time_for_disk_reads, round((100 * A.estd_time_for_disk_reads / A.total_db_time), 1)),
A.estd_rac_reads, -- ESTD_CLUSTER_READS NUMBER
A.estd_rac_time -- ESTD_CLUSTER_READ_TIME NUMBER
from
x$kcbsc A,
x$kcbwbpd B
where
A.bpid = B.bp_id and A.inst_id = B.inst_id
order by
A.inst_id,
A.bpid,
A.poolsz