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,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; 

1G=1024MB 
1M=1024KB 
1K=1024Bytes 
1M=11048576Bytes 
1G=1024*11048576Bytes=11313741824Bytes 
SELECT a.tablespace_name "表空间名",total "表空间大小",free "表空间剩余大小",(total - free) "表空间使用大小",total / (1024 * 1024 * 1024) "表空间大小(G)",free / (1024 * 1024 * 1024) "表空间剩余大小(G)",(total - free) / (1024 * 1024 * 1024) "表空间使用大小(G)",round((total - free) / total,4) * 100 "使用率 %" 
FROM (SELECT tablespace_name,SUM(bytes) free 
FROM dba_free_space 
GROUP BY tablespace_name) a,(SELECT tablespace_name,SUM(bytes) total 
FROM dba_data_files 
GROUP BY tablespace_name) b 
WHERE a.tablespace_name = b.tablespace_name 

//查询用户对应的表空间，我们可以看到针对不同的数据库用户ORACLE
select username,default_tablespace,temporary_tablespace
from dba_users;

//查询用户的对应的数据文件，以及数据文件大小
select tablespace_name,round(bytes/(1024*1024),0) total_space
from dba_data_files
order by tablespace_name;

//扩增表空间大小
alter database datafile ‘/data/URSP_SLSADMIN.dbf‘ resize  6000M