----查看undo相关参数
SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS2
SQL>
---创建一个undo的表空间
SQL> create undo tablespace undotbs1 datafile '/u01/app/oracle/oradata/ORA/undotbs1.dbf' size 100m autoextend on next 10m maxsize 300m;

Tablespace created.

SQL>
---切换一下undo的表空间

SQL> alter system set undo_tablespace=undotbs1;
\
System altered.

SQL>
-SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1
SQL>
---删掉一个undo表空间
SQL>drop tablespace undotbs2 including contents and datafiles;

Tablespace dropped.

SQL>
---改变undo保留数据的时间
SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1

SQL> alter system set undo_retention=600;

System altered.

ITPub博客

undo表空间

最新文章