sqlplus查询oracle数据库数据容量

登录sqlplus：

cmd命令行登录：sqlplus orcl/orcl as sysdba

查询表空间使用率

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

select tablespace_name, segment_name, bytes / 1024 / 1024 from user_segments where segment_type = \'TABLE\' and tablespace_name = \'VNOX\' order by bytes desc ;

查询表空间总大小(DBA_DATA_FILES和DBA_SEGMENTS,DBA_FREE_SPACE区别)

1, dba_data_files,dba_segments,dba_free_space
得出结论:一般情况下(没有drop表的时候):dba_data_files bytes = (dba_segments bytes + dba_free_space bytes)

实验:

SQL> Select sum(bytes)/1024/1024/1024 from dba_segments;
SUM(BYTES)/1024/1024/1024
-------------------------
1.58441162

SQL> select sum(bytes)/1024/1024/1024 from dba_free_space;
SUM(BYTES)/1024/1024/1024
-------------------------
.323669434

SQL> select sum(bytes)/1024/1024/1024 from dba_data_files;
SUM(BYTES)/1024/1024/1024
-------------------------
1.9140625