oracle 数据库里查看表空间使用状况

oracle 数据库里查看表空间使用状况；
oracle表空间的事情状况要经常查看，一般空闲比例过低的时候就应该考虑增大表看空间了。查看方法如下SQL:

方法一：

select dbf.tablespace_name,
dbf.totalspace "总量(M)",
dbf.totalblocks as 总块数,
dfs.freespace "剩余总量(M)",
dfs.freeblocks "剩余块数",
(dfs.freespace / dbf.totalspace) * 100 "空闲比例" 
from (select t.tablespace_name,
sum(t.bytes) / 1024 / 1024 totalspace,
sum(t.blocks) totalblocks
from dba_data_files t
group by t.tablespace_name) dbf,
(select tt.tablespace_name,
sum(tt.bytes) / 1024 / 1024 freespace,
sum(tt.blocks) freeblocks
from dba_free_space tt
group by tt.tablespace_name) dfs
where trim(dbf.tablespace_name) = trim(dfs.tablespace_name)

方法二：

SELECT Total.name "Tablespace Name",
Free_space, (total_space-Free_space) Used_space, total_space
FROM
(select tablespace_name, sum(bytes/1024/1024) Free_Space
from sys.dba_free_space
group by tablespace_name
) Free,
(select b.name, sum(bytes/1024/1024) TOTAL_SPACE
from sys.v_$datafile a, sys.v_$tablespace B
where a.ts# = b.ts#
group by b.name
) Total
WHERE Free.Tablespace_name = Total.name 

当发现有的表空间不够的错误时，处理如下：
1：找出该表空间对应的数据文件及路径

select * from dba_data_files t
where t.tablespace_name = ''ARD''

2：增大数据文件

alter database datafile ''全路径的数据文件名称'' resize ***M

3：增加数据文件

alter tablespace 表空间名称

add datafile ''全路径的数据文件名称'' ***M
注解：表空间尽量让free百分比保持在10%以上，如果低于10%就增加datafile或者resizedatafile，一般数据文件不要超过2G

=============查询表空间使用情况=======================
法一：
select a.tablespace_name, round(a.total_size) "total_size(MB)", 
round(a.total_size)-round(b.free_size,3) "used_size(MB)", 
round(b.free_size,3) "free_size(MB)", round(b.free_size/total_size*100,2)||'%' free_rate 
from ( select tablespace_name, sum(bytes)/1024/1024 total_size 
  from dba_data_files 
  group by tablespace_name ) a, 
  ( select tablespace_name, sum(bytes)/1024/1024 free_size 
  from dba_free_space 
  group by tablespace_name ) b 
  where a.tablespace_name = b.tablespace_name(+);
法二：
SELECT UPPER(F.TABLESPACE_NAME) "表空间名", 
D.TOT_GROOTTE_MB "表空间大小(M)", 
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)", 
TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100, 
2), 
'990.99') "使用比", 
F.TOTAL_BYTES "空闲空间(M)", 
F.MAX_BYTES "最大块(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 4 DESC
--order by F.TABLESPACE_NAME

====

select sum(maxbytes)/1024/1024/1024 from dba_data_files where tablespace_name='ETL_TBS'；