DBA_UNDO_EXTENTS

DBA_UNDO_EXTENTS describes the extents comprising the segments in all undo tablespaces in the database.

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 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:
  • ACTIVE

  • EXPIRED

  • UNEXPIRED