Oracle查询表占用的空间(表大小)的3种方法

DECLARE
  su NUMBER;
  sa NUMBER;
  cp NUMBER;
BEGIN
  dbms_space.object_space_usage('LOG'
                               ,'BIG_TABLE'
                               ,'TABLE'
                               ,NULL
                               ,su
                               ,sa
                               ,cp);
  dbms_output.put_line('Space Used: ' || to_char(su));
  dbms_output.put_line('Space Allocated: ' || to_char(sa));
  dbms_output.put_line('Chained Percentage: ' || to_char(cp));
END;

SELECT segment_name "表名",
       segment_type "对象类型",
       sum(bytes) / 1024 / 1024 "占用空间（MB）"
  FROM dba_extents
 WHERE 1=1
   -- AND segment_name = '表名'
 GROUP BY segment_name, segment_type
 ORDER BY "占用空间（MB）" DESC;

SELECT owner,
       segment_name,
       segment_type,
       sum(bytes) / 1024 / 1024 "占用空间（MB）"
  FROM dba_segments
 WHERE 1=1
    -- AND owner = '表所有者'
 GROUP BY owner, segment_name, segment_type
 ORDER BY "占用空间（MB）" DESC;