V$MAP_FILE_EXTENT

V$MAP_FILE_EXTENT contains 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_IDX in V$MAP_FILE)
EXT_NUM	NUMBER	File extent number
EXT_ELEM_OFF	NUMBER	Element offset in HKB
EXT_SIZE	NUMBER	File extent size in HKB
EXT_FILE_OFF	NUMBER	File Offset in HKB
EXT_TYPE	VARCHAR2(6)	File Extent Type (DATA, PARITY, or NONE)
ELEM_IDX	NUMBER	Index in V$MAP_ELEMENT corresponding to the element where the file extent resides