查询表空间使用情况：
select a.tablespace_name,total,free,total-free used from
( select tablespace_name,sum(bytes)/1024/1024 total from dba_data_files
group by tablespace_name) a,
( select tablespace_name,sum(bytes)/1024/1024 free from dba_free_space
group by tablespace_name) b
where a.tablespace_name=b.tablespace_name;
修改表空间大小：
alter database datafile 'E:/oracle/product/10.2.0/oradata/DEV/DEV_CENTER.DBF' resize 500m;
