Oracle表空间监控

1. 查看所有表空间大小SQL> select tablespace_name,sum(bytes)/1024/1024 from dba_data_files  2  group by tablespace_name;2. 已经使用的表空间大小SQL> select tablespace_name,sum(bytes)/1024/1024 from dba_free_space  2  group by tablespace_name;3. 所以使用空间可以这样计算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) bwhere a.tablespace_name=b.tablespace_name;4. 下面这条语句查看所有segment的大小。Select Segment_Name,Sum(bytes)/1024/1024 From User_Extents Group By Segment_Name5. 还有在命令行情况下如何将结果放到一个文件里。SQL> spool out.txtSQL> select * from v$database;SQL> spool off--计算所有表空间文件大小，计算每个表空间占用百分比的除数select '表空间文件大小' tablespacesizename, (select  sum(tablespacesize)||'MB' from (select tablespace_name, sum(bytes/1024/1024) as tablespacesize from dba_data_files group by tablespace_name)) tablespacesize from dual;