1、查看表空间的名称及大小
select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size
from dba_tablespaces t, dba_data_files d
where t.tablespace_name = d.tablespace_name
group by t.tablespace_name;2、查看表空间物理文件的名称及大小
select tablespace_name, file_id, file_name,
round(bytes/(1024*1024),0) total_space
from dba_data_files
order by tablespace_name;
3、查看回滚段名称及大小
select segment_name, tablespace_name, r.status,
(initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent,
max_extents, v.curext CurExtent
From dba_rollback_segs r, v$rollstat v
Where r.segment_id = v.usn(+)
order by segment_name ;
4、查看控制文件
select name from v$controlfile;
5、查看日志文件
select member from v$logfile;
6、查看表空间的使用情况
select sum(bytes)/(1024*1024) as free_space,tablespace_name
from dba_free_space
group by tablespace_name;
SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE,
(B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE"
FROM SYS.SM$TS_AVAIL A,SYS.SM$TS_USED B,SYS.SM$TS_FREE C
WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME;
7、查看数据库库对象
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;
8、查看数据库的版本
Select version FROM Product_component_version
Where SUBSTR(PRODUCT,1,6)='Oracle';
9、查看数据库的创建日期和归档方式
Select Created, Log_Mode, Log_Mode From V$Database;
10、查看当前所有对象
select * from tab;
11、建一个和a表结构一样的空表
create table b as select * from a where 1=2;
create table b(b1,b2,b3) as select a1,a2,a3 from a where 1=2;
12、察看数据库的大小，和空间使用情况
col tablespace format a20
select b.file_id --文件ID,
b.tablespace_name --表空间,
b.file_name --物理文件名,
b.bytes --总字节数,
(b.bytes-sum(nvl(a.bytes,0))) --已使用,
sum(nvl(a.bytes,0)) --剩余,
sum(nvl(a.bytes,0))/(b.bytes)*100 --剩余百分比
from dba_free_space a,dba_data_files b
where a.file_id=b.file_id
group by b.tablespace_name,b.file_name,b.file_id,b.bytes
order by b.tablespace_name
/
dba_free_space --表空间剩余空间状况
dba_data_files --数据文件空间占用情况
13、查看现有回滚段及其状态
col segment format a30
SELECT SEGMENT_NAME,OWNER,TABLESPACE_NAME,SEGMENT_ID,FILE_ID,STATUS FROM DBA_ROLLBACK_SEGS;
14、查看数据文件放置的路径
col file_name format a50
select tablespace_name,file_id,bytes/1024/1024,file_name from dba_data_files order by file_id;
15、显示当前连接用户
show user
16、把SQL*Plus当计算器
select 100*20 from dual;
17、连接字符串
select 列1||列2 from 表1;
select concat(列1,列2) from 表1;
18、查询当前日期
select to_char(sysdate,'yyyy-mm-dd,hh24:mi:ss') from dual;
19、用户间复制数据
copy from user1 to user2 create table2 using select * from table1;
20、视图中不能使用order by，但可用group by代替来达到排序目的
create view a as select b1,b2 from b group by b1,b2;
21、通过授权的方式来创建用户
grant connect,resource to test identified by test;
conn test/test;
posted on 2008-02-22 01:10
浩霖 阅读(182)
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