oracle查看用户占用空间

查看用户 或 表 占用了多少空间：

SELECT TABLESPACE_NAME,
       round(SUM(BYTES) /1024 / 1024 / 1024, 3)  占用空间G
  FROM DBA_EXTENTS
 WHERE OWNER = '&OWNER'
  -- AND SEGMENT_NAME = '&TABLE_NAME'
  -- AND SEGMENT_TYPE LIKE 'TABLE%'
 GROUP BY TABLESPACE_NAME;