彙總函數和百分比值總計

Question

我試圖通過使用ROLLUP函數來顯示錶空間使用情況，並且結果看起來不錯。但是，正如您所看到的，Total的percent_free只是一個總和而不是百分比。 你能幫我改變下面的查詢來獲得Total的百分比值嗎？

SELECT nvl(df.tablespace_name,'Total') TABLESPACE, 
    sum(df.total_space_mb) TOTAL_SPACE_MB, 
    sum((df.total_space_mb - fs.free_space_mb)) USED_SPACE_MB, 
    sum(fs.free_space_mb) FREE_SPACE_MB, 
    sum(ROUND(100 * (fs.free_space/df.total_space),2)) PERCENT_FREE 
FROM (SELECT tablespace_name, SUM(bytes) TOTAL_SPACE, 
    ROUND(SUM(bytes)/1048576) TOTAL_SPACE_MB 
    FROM dba_data_files 
    GROUP BY tablespace_name) df, 
    (SELECT tablespace_name, SUM(bytes) FREE_SPACE, 
    ROUND(SUM(bytes)/1048576) FREE_SPACE_MB 
    FROM dba_free_space 
    GROUP BY tablespace_name) fs 
WHERE df.tablespace_name = fs.tablespace_name(+) 
GROUP BY rollup(df.tablespace_name) 
ORDER BY df.tablespace_name 


TABLESPACE  TOTAL_SPACE_MB USED_SPACE_MB FREE_SPACE_MB PERCENT_FREE 
--------------- -------------- ------------- ------------- ------------ 
DEMO      1500   47   1453  96.87 
NORMAL      10    1    9  88.75 
SYSAUX     7990   7600   390   4.88 
SYSTEM      970   961    9   .9 
UNDOTBS1     1690   24   1666  98.57 
USERS      5275   964   4311  81.73 
Total     17435   9597   7838  371.7 

Answer 1

您可以使用DECODE此：

DECODE(df.tablespace_name, NULL, 
     ROUND(100*SUM(fs.FREE_SPACE)/SUM(df.total_space),2), 
     SUM(ROUND(100 * (fs.free_space/df.total_space),2))) PERCENT_FREE, 

當它是「總計」行（TABLESPACE_NAME爲null）使用金額上全面超過了整個表。然後像往常一樣在DECODE的else子句中計算其他行。

SELECT nvl(df.tablespace_name,'Total') TABLESPACE, 
    sum(df.total_space_mb) TOTAL_SPACE_MB, 
    sum((df.total_space_mb - fs.free_space_mb)) USED_SPACE_MB, 
    sum(fs.free_space_mb) FREE_SPACE_MB, 
    DECODE(df.tablespace_name, NULL, 
     ROUND(100*SUM(fs.FREE_SPACE)/SUM(df.total_space),2), 
     SUM(ROUND(100 * (fs.free_space/df.total_space),2))) PERCENT_FREE 
FROM (SELECT tablespace_name, SUM(bytes) TOTAL_SPACE, 
    ROUND(SUM(bytes)/1048576) TOTAL_SPACE_MB 
    FROM dba_data_files 
    GROUP BY tablespace_name) df, 
    (SELECT tablespace_name, SUM(bytes) FREE_SPACE, 
    ROUND(SUM(bytes)/1048576) FREE_SPACE_MB 
    FROM dba_free_space 
    GROUP BY tablespace_name) fs 
WHERE df.tablespace_name = fs.tablespace_name(+) 
GROUP BY rollup(df.tablespace_name) 
ORDER BY df.tablespace_name