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【DM版本】:8.0
【操作系统】：CentOS 7.9
【CPU】:48c Model name: Intel® Xeon® Gold 6126 CPU @ 2.60GHz

【问题描述】*：
通过视图 dba_data_files 和 dba_free_space 统计的表空间已使用空间跟 dba_segments里汇总统计的值差别很大。

SELECT F.TABLESPACE_NAME,
       ROUND((T.TOTAL_SPACE - F.FREE_SPACE) / 1024) "USED (GB)",
       ROUND(F.FREE_SPACE / 1024) "FREE (GB)",
       ROUND(T.TOTAL_SPACE / 1024)  "TOTAL(GB)",
       (ROUND((F.FREE_SPACE / T.TOTAL_SPACE) * 100)) ||  '% ' PER_FREE
  FROM (SELECT TABLESPACE_NAME,
               ROUND(SUM(BLOCKS *
                         (SELECT PARA_VALUE / 1024
                            FROM V$DM_INI
                           WHERE PARA_NAME = 'GLOBAL_PAGE_SIZE') / 1024)) FREE_SPACE
          FROM DBA_FREE_SPACE
         GROUP BY TABLESPACE_NAME) F,
       (SELECT TABLESPACE_NAME, ROUND(SUM(BYTES / 1048576)) TOTAL_SPACE
          FROM DBA_DATA_FILES
         GROUP BY TABLESPACE_NAME) T
 WHERE F.TABLESPACE_NAME = T.TABLESPACE_NAME AND T.TABLESPACE_NAME LIKE 'SYSBENCHDB%';

LINEID     TABLESPACE_NAME USED (GB) FREE (GB) TOTAL(GB) PER_FREE
---------- --------------- --------- --------- --------- --------
1          SYSBENCHDB      3040      6         3046      0%

SELECT sum(bytes)/1024/1024/1024 size_gb
FROM dba_segments 
WHERE tablespace_name='SYSBENCHDB';

LINEID     SIZE_GB
---------- --------------------
1          1583

used time: 00:00:11.799. Execute id is 36261901.

上面一个说表空间已使用 3040GB，一个说是1583GB。 我之前确实有删除表的操作。