5). 检查数据文件的状态记录状态不是“online”的数据文件，并做恢复。
select file_name from dba_data_files where status=’offline’
(6). 检查表空间的使用情况
select tablespace_name, max_m, count_blocks free_blk_cnt, sum_free_m,to_char(100*sum_free_m/sum_m, 99.99) || % as pct_free
from ( select tablespace_name,sum(bytes)/1024/1024 as sum_m from dba_data_files group by tablespace_name),
( select tablespace_name as fs_ts_name, max(bytes)/1024/1024 as max_m, count(blocks) as count_blocks, sum(bytes/1024/1024) as sum_free_m from dba_free_space group by tablespace_name )
where tablespace_name = fs_ts_name
(7). 检查剩余表空间
select tablespace_name, sum ( blocks ) as free_blk ,
trunc ( sum ( bytes ) /(1024*1024) ) as free_m,
max ( bytes ) / (1024) as big_chunk_k, count (*) as num_chunks
from dba_free_space group by tablespace_name;

查询字符集：

select *  from V$NLS_PARAMETERS

select  userenv('language') from dual