删除一个过大的UNDOTBS
select file_name,bytes/1024/1024 from dba_data_files where autoextensible='YES';一般自动扩展最容易变得很大的就是untotbs/oradata/rmdb/undotbs01.dbf 32G处理过程：(1) 生成autoextend off语句select 'alter database datafile '''||file_name||''' AUTOEXTEND OFF;' from dba_data_files where autoextensible='YES';(2) 新建一个undotbscreate undo tablespace undotbs1 datafile '/opt/oracle/oradata/ora11g/undotbs01.dbf' size 500m;(3) 切换undotbs,并记录到spfilealter system set undo_tablespace=UNDOTBS2 scope=both;(4) 过几天再把undotbs1干掉drop tablespace undotbs1 including contents and datafiles cascade constraints;?清理UNDO表空间SQL>connsys/sss@sssdbas sysdbaSQL>create undo tablespace UNDOTBS2 datafile 'C:\oracle\oradata\sssdb\UNDOTBS02.DBF'size 1M extent management local;SQL>alter system set undo_tablespace=UNDOTBS2;SQL>drop tablespace UNDOTBS1 including contents;SQL>shutdown immediateSQL>host del C:\oracle\oradata\sssdb\UNDOTBS01.DBF;如果删除文件失败，请重新启动计算机后再删除。
