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 | 
File identifier 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 number of the file containing the segment header | 
COMMIT_JTIME | 
NUMBER | 
  | 
Commit time of the undo in the extent expressed as Julian time. This column is deprecated, but retained for backward compatibility reasons. | 
COMMIT_WTIME | 
VARCHAR2(20) | 
  | 
Commit time of the undo in the extent expressed as Wallclock time.This column is deprecated, but retained for backward compatibility reasons | 
STATUS | 
VARCHAR2(9) | 
  | 
Transaction Status of the undo in the extent:
 |