DBA_UNDO_EXTENTS

DBA_UNDO_EXTENTS lists the commit time for each extent in the undo tablespace.

Column	Datatype	NULL	Description
OWNER	CHAR(3)		Owner of the undo tablespace
SEGMENT_NAME	VARCHAR2(30)	NOT NULL	Name of the undo segment
TABLESPACE_NAME	VARCHAR2(30)	NOT NULL	Name of the undo tablespace
EXTENT_ID	NUMBER		ID of the extent
FILE_ID	NUMBER	NOT NULL	Number of the file containing the extent
BLOCK_ID	NUMBER		Start block number of the extent
BYTES	NUMBER		Size of the extent in bytes
BLOCKS	NUMBER		Size of the extent in blocks
RELATIVE_FNO	NUMBER		Relative file number of the segment header
COMMIT_JTIME	NUMBER		Commit time of the extent expressed as Julian time
COMMIT_WTIME	VARCHAR2(20)		Commit time of the extent expressed as Wallclock time