SELECT segment_name, segment_type, owner, a.tablespace_name "tablespace_name",
       initial_Extent, next_extent, pct_increase, b.bytes "tablespace max free space"
  FROM dba_segments a,
       (SELECT tablespace_name,max(bytes) Bytes
          FROM dba_free_space
         GROUP BY tablespace_name) b
 WHERE a.tablespace_name=b.tablespace_name AND next_extent>b.bytes
 
 -- показывает все таблицы и индексы с числом экстентов более 1
 
SELECT * FROM DBA_EXTENTS WHERE owner='UBC' AND extent_id>0