Oracle各种空间大小及占用大小

1. 表占用空间大小计算方法 Select S.SEGMENT_NAME ,DECODE(SUM(BYTES), NULL, 0, SUM(BYTES) / 1024 / 1024) Mbytes From

1.       表占用空间大小计算方法

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.       索引占用空间大小计算方法

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.       分区表占用空间大小计算方法

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.       表空间使用情况

SELECT A.TABLESPACE_NAME 表空间名称,

Round(A.BYTES, 2) "总空间(G)",

Round(B.BYTES, 2) "未用空间(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;

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