第40章 管理还原数据

第40章 管理还原数据

undo是保存DML操作之前的数据
日志文件保存更改的操作
查询所有表空间
select name from v$datafile;

删除表undo表空间
ho rm /u01/oracle/oradata/wyzc10g/undotbs01.dbf
shutdown immediate
startup

show parameter undo_m
alter system set undo_management=manual scope=spfile;
shutdown
startup
alter database datafiel 2 offile drop
alter database open;
drop tablespace undotbs1;
create undo tablespace undotbd1 datafile '/u01/oracle/oradata/wyzc10g/undotbs01.dbf' size 10m autoextend on;
alter system set undo_managerment scope=spfile;
shutdown immediate
startup