V$MAP_FILE_EXTENT displays a list of all file extent mapping structures in the shared memory of the instance.
| Column | Datatype | Description | 
|---|---|---|
| FILE_MAP_IDX | NUMBER | File index (corresponds to FILE_MAP_IDXinV$MAP_FILE) | 
| EXT_NUM | NUMBER | File extent number | 
| EXT_ELEM_OFF | NUMBER | Element offset in HKB | 
| EXT_SIZE | NUMBER | File extent size in HKB | 
| EXT_FILE_OFF | NUMBER | File Offset in HKB | 
| EXT_TYPE | VARCHAR2(6) | File Extent Type: 
 | 
| ELEM_IDX | NUMBER | Index in V$MAP_ELEMENTcorresponding to the element where the file extent resides |