DBA_HIST_DB_CACHE_ADVICE displays historical predictions of the number of physical reads for the cache size corresponding to each row. This view contains snapshots of V$DB_CACHE_ADVICE.
| Column | Datatype | NULL | Description |
|---|---|---|---|
SNAP_ID |
NUMBER |
Unique snapshot ID | |
DBID |
NUMBER |
Database ID for the snapshot | |
INSTANCE_NUMBER |
NUMBER |
Instance number for the snapshot | |
BPID |
NUMBER |
Buffer Pool identifier (ranges from 1 to 8) | |
BUFFERS_FOR_ESTIMATE |
NUMBER |
Cache size for prediction (in terms of buffers) | |
NAME |
VARCHAR2(20) |
Buffer pool name | |
BLOCK_SIZE |
NUMBER |
Block size in bytes for buffers in the pool (the standard block size, the power of 2 non-standard block sizes, 2048, 4096, 8192, 16384, or 32768) | |
ADVICE_STATUS |
VARCHAR2(3) |
Status of the advisory:
|
|
SIZE_FOR_ESTIMATE |
NUMBER |
Cache size for prediction (in megabytes) | |
SIZE_FACTOR |
NUMBER |
Size factor with respect to the current cache size | |
PHYSICAL_READS |
NUMBER |
Physical reads for the cache size | |
BASE_PHYSICAL_READS |
NUMBER |
Base physical reads for the cache size | |
ACTUAL_PHYSICAL_READS |
NUMBER |
Actual physical reads for the cache size |