常用的查看數據庫的sql
查看數據庫的sql 
1、查看表空間的名稱及大小 
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、查看表空間物理文件的名稱及大小 
select tablespace_name, file_id, file_name, 
round(bytes/(1024*1024),0) total_space 
from dba_data_files 
order by tablespace_name; 
3、查看回滾段名稱及大小 
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$logfile; 
6、查看表空間的使用情況 
select sum(bytes)/(1024*1024) as free_space,tablespace_name 
from dba_free_space 
group by tablespace_name; 
select a.tablespace_name,a.bytes total,b.bytes used, c.bytes free, 
(b.bytes*100)/a.bytes "% used",(c.bytes*100)/a.bytes "% free" 
from sys.sm$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、查看數據庫庫對象 
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status; 
8、查看數據庫的版本  
select version from product_component_version 
where substr(product,1,6)='oracle'; 
9、查看數據庫的創建日期和歸檔方式 
select created, log_mode, log_mode from v$database;