V$MAP_FILE_IO_STACK displays the hierarchical arrangement of storage containers for files. Each row in the view represents a level in the hierarchy.
| Column | Datatype | Description |
|---|---|---|
FILE_MAP_IDX |
NUMBER |
File index (corresponds to FILE_MAP_IDX in V$MAP_FILE) |
DEPTH |
NUMBER |
Element depth within the I/O stack |
ELEM_IDX |
NUMBER |
Index corresponding to the element |
CU_SIZE |
NUMBER |
Contiguous set of logical blocks of the file (in HKB units) that is resident contiguously on the element |
STRIDE |
NUMBER |
Number of HKB between contiguous units (CU) in the file that are contiguous on this element. Used in RAID5 and striped files. |
NUM_CU |
NUMBER |
Number of contiguous units that are adjacent to each other on this element that are separated by STRIDE HKB in the file. In RAID5, the number of contiguous units also include the parity stripes. |
ELEM_OFFSET |
NUMBER |
Element offset in HKB units |
FILE_OFFSET |
NUMBER |
Offset in HKB units from the start of the file to the first byte of the contiguous units |
DATA_TYPE |
VARCHAR2(15) |
Datatype:
|
PARITY_POS |
NUMBER |
Position of the parity. Only for RAID5. This column is needed to distinguish the parity from the data part. |
PARITY_PERIOD |
NUMBER |
Parity period. Only for RAID5. |
ID |
NUMBER |
Unique identifier |
PARENT_ID |
NUMBER |
Parent identifier |