Oracle各類空間大小及佔用大小

1.       表佔用空間大小計算方法

Select S.SEGMENT_NAME ,DECODE(SUM(BYTES), NULL, 0, SUM(BYTES) / 1024 / 1024) Mbytes
  From DBA_SEGMENTS S
 Where S.SEGMENT_NAME = 'MTL_MATERIAL_TRANSACTIONS' --表名
   And S.SEGMENT_TYPE = 'TABLE'
 Group By S.SEGMENT_NAME

2.       索引佔用空間大小計算方法

Select S.SEGMENT_NAME ,DECODE(SUM(BYTES), NULL, 0, SUM(BYTES) / 1024 / 1024) Mbytes
  From DBA_SEGMENTS S
 Where S.SEGMENT_NAME = 'MTL_MATERIAL_TRANSACTIONS_N1' --索引
   And S.SEGMENT_TYPE = 'INDEX'
 Group By S.SEGMENT_NAME

3.       分區表佔用空間大小計算方法

Select S.SEGMENT_NAME ,DECODE(SUM(BYTES), NULL, 0, SUM(BYTES) / 1024 / 1024) Mbytes
  From DBA_SEGMENTS S
 Where S.SEGMENT_TYPE = 'TABLE PARTITION'
 Group By S.SEGMENT_NAME

4.       表空間使用狀況

SELECT A.TABLESPACE_NAME 表空間名稱,
       Round(A.BYTES, 2) "總空間(G)",
       Round(B.BYTES, 2) "未用空間(G)",
       ROUND(((A.BYTES - B.BYTES) / A.BYTES) * 100, 2) "使用率%"
  FROM (SELECT TABLESPACE_NAME, SUM(BYTES) / (1024 * 1024 * 1024) BYTES
          FROM DBA_DATA_FILES
         GROUP BY TABLESPACE_NAME) A,
       (SELECT TABLESPACE_NAME, SUM(BYTES) / (1024 * 1024 * 1024) BYTES
          FROM DBA_FREE_SPACE
         GROUP BY TABLESPACE_NAME) B
 WHERE A.TABLESPACE_NAME = B.TABLESPACE_NAME
 ORDER BY ((A.BYTES - B.BYTES) / A.BYTES) DESC;