UNDO表空间备份恢复


UNDO表空间在有热备没有事物交易的时候有数据块损坏的恢复

第一，先看一下确保undo表空间里没有交易的事物

SQL>select XID USN,XIDSLOT,XIDSQN fromv$transaction;

no rows selected

第二，确认当前所用的回退表空间

SQL>show parameter undo



NAME                                          TYPE     VALUE

------------------------------------     -----------  ------------------------------

undo_management                     string     AUTO

undo_retention                             integer       900

undo_tablespace                    string         UNDOTBS1

第三查看表空间对应的数据文件

SQL>select   tablespace_name,file_name from dba_data_Files

TABLESPACE_NAME                FILE_NAME

------------------------------             ----------------------------------------

USERS                          /u01/tiger/oradata/orcl2/users01.dbf

SYSAUX                        /u01/tiger/oradata/orcl2/sysaux01.dbf

SYSTEM                        /u01/tiger/oradata/orcl2/system01.dbf

UNDOTBS2                      /u01/tiger/oradata/orcl2/undotbs02.dbf

TIGER                         /u01/tiger/oradata/orcl2/tiger.dbf

第四查看数据文件的状态

SQL> selectfile#,name,status,recover,error from v$datafile_header;



FILE#   NAME                                   STATUS         REC          ERROR

----------    ----------------------------------------                            -------                 ---            --------------------

  1          /u01/tiger/oradata/orcl2/system01.dbf     ONLINE                   NO

  3          /u01/tiger/orad