oracle table space usage statistics query

--Query table space usage 
SELECT  Upper (F.TABLESPACE_NAME) "table space name",
       D.TOT_GROOTTE_MB "Table space size (M)",
       D.TOT_GROOTTE_MB - F.TOTAL_BYTES "Space used (M)",
       To_char( Round (( D.TOT_GROOTTE_MB - F.TOTAL_BYTES ) / D.TOT_GROOTTE_MB *  100 , 2 ), ' 990.99 ' )
        ||  ' % '                            "Use ratio",
       F.TOTAL_BYTES "Free space (M)",
       F.MAX_BYTES "Maximum block (M)"
FROM   (SELECT TABLESPACE_NAME,
               Round(Sum(BYTES) / ( 1024 * 1024 ), 2) TOTAL_BYTES,
               Round(Max(BYTES) / ( 1024 * 1024 ), 2) MAX_BYTES
        FROM   SYS.DBA_FREE_SPACE
        GROUP  BY TABLESPACE_NAME) F,
       (SELECT DD.TABLESPACE_NAME,
               Round(Sum(DD.BYTES) / ( 1024 * 1024 ), 2) TOT_GROOTTE_MB
        FROM   SYS.DBA_DATA_FILES DD
        GROUP  BY DD.TABLESPACE_NAME) D
WHERE  D.TABLESPACE_NAME = F.TABLESPACE_NAME
ORDER  BY 1

--查询表空间的free space
select tablespace_name, count(*) AS extends,round(sum(bytes) / 1024 / 1024, 2) AS MB,sum(blocks) AS blocks from dba_free_space group BY tablespace_name;

--Query the total capacity of the 
tablespace select tablespace_name, sum (bytes) /  1024  /  1024  as MB from dba_data_files group  by tablespace_name;
 --Query the tablespace usage 
SELECT total.tablespace_name,
        Round (total.MB, 2 )            AS Total_MB,
        Round (total.MB - free.MB, 2 ) AS Used_MB,
        Round (( 1  - free.MB / total.MB ) *  100, 2)
       || '%'                       AS Used_Pct
FROM   (SELECT tablespace_name,
               Sum(bytes) / 1024 / 1024 AS MB
        FROM   dba_free_space
        GROUP  BY tablespace_name) free,
       (SELECT tablespace_name,
               Sum(bytes) / 1024 / 1024 AS MB
        FROM   dba_data_files
        GROUP  BY tablespace_name) total
WHERE  free.tablespace_name = total.tablespace_name;