Oracle各種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.       資料表空間使用方式

SELECT A.TABLESPACE_NAME 資料表空間名稱,

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;