未完待续……未完待续……未完待续……未完待续…… 1.查询某个表所占空间大小 col tablespace_name for a15 col segment_name for a15 col segment_type for a15 select segment_name,segment_type,tablespace_name,extents,bytes/1024 KB from dba_segment

未完待续……未完待续……未完待续……未完待续……

1.查询某个表所占空间大小

col tablespace_name for a15
col segment_name for a15
col segment_type for a15

select segment_name,segment_type,tablespace_name,extents,bytes/1024 KB from dba_segments where segment_name like 'TEST%';

结果如下：

SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME EXTENTS KB
--------------- --------------- --------------- ---------- ----------
TEST TABLE USERS 1
TEST1 TABLE USERS 1
TEST1 TABLE USERS 168 794624
TEST5 TABLE RMANTEST 1
TEST9 TABLE USERS 169 800768

3.某个用户下的表所占空间前三位:

select * from (select segment_name,bytes/1024 KB from dba_segments where owner = 'BYS' order by bytes desc ) where rownum <= 3;
SEGMENT_NAME KB
--------------- ----------
TEST9 800768
TEST1 794624
EMP
用SQL计算出某个用户下所有对象的大小，给出SQL语句和结果。
SQL> show user
User is "bys"

SQL> select sum(a.m) from (select segment_name,segment_type,bytes/1024/1024 M from user_segments) a;

SUM(A.M)
----------
4

2.查询表空间大小及空闲空间大小，使用率等

主要使用的视图有：dba_data_files，dba_free_space

col used_% for a8

col TABLESPACE_NAME for a15

select df.tablespace_name,df.sum_df_m as space_m,df.sum_df_m-fs.sum_fs_m as used_m,fs.sum_fs_m as free_space,to_char(trunc((df.sum_df_m-fs.sum_fs_m)/df.sum_df_m,2)*100) as "used_%",100-to_char(trunc((df.sum_df_m-fs.sum_fs_m)/df.sum_df_m,2)*100) "unused_%" from (select tablespace_name,sum(bytes/1024/1024) as sum_df_m from dba_data_files group by tablespace_name) df,(select tablespace_name,sum(bytes/1024/1024) as sum_fs_m from dba_free_space group by tablespace_name) fs where df.tablespace_name=fs.tablespace_name;

结果如下：
TABLESPACE_NAME SPACE_M USED_M FREE_SPACE used_% unused_%
------------------------------ ---------- ---------- ---------- -------- ----------
SYSAUX 625.625 595.625 30 95 5
UNDOTBS1 200 137.4375 62.5625 68 32
USERS 219.8125 121.875 97.9375 55 45
SYSTEM 500 346.1875 153.8125 69 31
TEST1 110 2 108 1 99

select df.tablespace_name,df.sum_df_m as space_m,df.sum_df_m-fs.sum_fs_m as used_m,fs.sum_fs_m as free_space,to_char(trunc((df.sum_df_m-fs.sum_fs_m)/df.sum_df_m,2)*100) as "used_%" from (select tablespace_name,sum(bytes/1024/1024) as sum_df_m from dba_data_files group by tablespace_name) df,(select tablespace_name,sum(bytes/1024/1024) as sum_fs_m from dba_free_space group by tablespace_name) fs where df.tablespace_name=fs.tablespace_name and df.tablespace_name='USERS';

结果如下：

TABLESPACE_NAME SPACE_M USED_M FREE_SPACE used_%
--------------- ---------- ---------- ---------- --------
USERS 1703.75 1562.5 141.25 91

.用SQL计算某个表空间所包含对象的大小

3.查询数据文件大小及文件名

col file_name for a35
select file_name,file_id,tablespace_name,bytes/1024/1024 MB from dba_data_files;

FILE_NAME FILE_ID TABLESPACE_NAME MB
----------------------------------- ---------- --------------- ----------
/u01/oradata/bys1/users01.dbf 4 USERS 1703.75
/u01/oradata/bys1/undotbs01.dbf 3 UNDOTBS1 125
/u01/oradata/bys1/sysaux01.dbf 2 SYSAUX 670
/u01/oradata/bys1/system01.dbf 1 SYSTEM 700
/u01/oradata/bys1/example01.dbf 5 EXAMPLE 100
/u01/oradata/bys1/rmantest.dbf 6 RMANTEST 10

4.查询整个数据库的容量

数据文件大小
select sum(m) as sum_d from (select file_name,tablespace_name,bytes/1024/1024 m from dba_data_files union select file_name,tablespace_name,bytes/1024/1024 m from dba_temp_files);
重做日志文件大小
select sum(a.members*a.m) as sum_r from (select group#,members,bytes/1024/1024 m from v$log) a;
控制文件大小
SQL> select sum(bytes_m) as sum_c from (select name,block_size*file_size_blks/1024/1024 as bytes_m from v$controlfile);
数据库总容量：
SQL> select sum_d+sum_r+sum_c as sum_database_M,sum_d as sum_datafile,sum_r as sum_redo,sum_c as sum_ctl from (select sum(m) as sum_d from (select file_name,tablespace_name,bytes/1024/1024 m from dba_data_files union select file_name,tablespace_name,bytes/1024/1024 m from dba_temp_files)) a,(select sum(members*m) as sum_r from (select group#,members,bytes/1024/1024 m from v$log)) b,(select sum(bytes_m) as sum_c from (select name,block_size*file_size_blks/1024/1024 as bytes_m from v$controlfile)) c;

SUM_DATABASE_M SUM_DATAFILE SUM_REDO SUM_CTL
-------------- ------------ ---------- ----------
2733.75 2615.25 90 28.5