DBA_EXTENTS

DBA_EXTENTS describes the extents comprising all segments in the database.

Related view:

• USER_EXTENTS describes extents in segments associated with objects owned by the current user. This view does not display the OWNER, FILE_ID, BLOCK_ID, or RELATIVE_FNO columns.

  Column	Datatype	NULL	Description
  OWNER	VARCHAR2(30)		Owner of the segment associated with the extent
  SEGMENT_NAME	VARCHAR2(81)		Name of the segment associated with the extent
  SEGMENT_TYPE	VARCHAR2(17)		Type of the segment: INDEX PARTITION, TABLE PARTITION
  TABLESPACE_NAME	VARCHAR2(30)		Name of the tablespace containing the extent
  EXTENT_ID	NUMBER	NOT NULL	Extent number in the segment
  FILE_ID	NUMBER	NOT NULL	Name of the file containing the extent
  BLOCK_ID	NUMBER	NOT NULL	Starting block number of the extent
  BYTES	NUMBER		Size of the extent in bytes
  BLOCKS	NUMBER	NOT NULL	Size of the extent in Oracle blocks
  RELATIVE_FNO	NUMBER	NOT NULL	Relative file number of the first extent block
  PARTITION_NAME	VARCHAR2(30)		Object Partition Name (Set to NULL for non-partitioned objects)