oracle切换undo表空间

时间 2019-12-05

标签 oracle 切换 undo 空间栏目 Oracle 繁體版

原文原文链接

Oracle里的回滚表空间在数据库使用一段时间后，undo表空间的dbf文件每每会增加到比较大，这个时候咱们须要切换undo表空间数据库

1.新建undo表空间spa

SQL> create undo tablespace undotbs2 datafile '/data/undotbs02.dbf' size 10M autoextend on next 10M ;get

2.因为undo_tablespace是个动态参数，因此任什么时候候均可以set。string

SQL> alter system set undo_tablespace='undotbs2' scope=both; io

系统已更改。 table

3.查看原来的undo表空间中的undo segment是否都为offlinefile

SQL> select tablespace_name,segment_name,status from dba_rollback_segs; select

TABLESPACE_NAME SEGMENT_NAME STATUS next

------------------------------ ------------------------------ ---------------- 数据

SYSTEM SYSTEM ONLINE

UNDOTBS1 _SYSSMU1$ OFFLINE

UNDOTBS1 _SYSSMU2$ OFFLINE

UNDOTBS1 _SYSSMU3$ OFFLINE

UNDOTBS1 _SYSSMU4$ OFFLINE

UNDOTBS1 _SYSSMU5$ OFFLINE

UNDOTBS1 _SYSSMU6$ OFFLINE

UNDOTBS1 _SYSSMU7$ OFFLINE

UNDOTBS1 _SYSSMU8$ OFFLINE

UNDOTBS1 _SYSSMU9$ OFFLINE

UNDOTBS1 _SYSSMU10$ OFFLINE

UNDOTBS2 _SYSSMU11$ ONLINE

UNDOTBS2 _SYSSMU12$ ONLINE

UNDOTBS2 _SYSSMU13$ ONLINE

UNDOTBS2 _SYSSMU14$ ONLINE

UNDOTBS2 _SYSSMU15$ ONLINE

UNDOTBS2 _SYSSMU16$ ONLINE

UNDOTBS2 _SYSSMU17$ ONLINE

UNDOTBS2 _SYSSMU18$ ONLINE

UNDOTBS2 _SYSSMU19$ ONLINE

TABLESPACE_NAME SEGMENT_NAME STATUS

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

UNDOTBS2 _SYSSMU20$ ONLINE

21 rows selected www.2cto.com

原来undotbs1的undo_segment 都为offline，则能够删除undotbs1.

SQL> alter tablespace undotbs1 offline;

SQL> drop tablespace undotbs1 including contents and datafiles;

表空间已删除。

再次查看：

SQL> select tablespace_name,segment_name,status from dba_rollback_segs;

TABLESPACE_NAME SEGMENT_NAME STATUS

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

SYSTEM SYSTEM ONLINE

UNDOTBS2 _SYSSMU11$ ONLINE

UNDOTBS2 _SYSSMU12$ ONLINE

UNDOTBS2 _SYSSMU13$ ONLINE

UNDOTBS2 _SYSSMU14$ ONLINE

UNDOTBS2 _SYSSMU15$ ONLINE

UNDOTBS2 _SYSSMU16$ ONLINE

UNDOTBS2 _SYSSMU17$ ONLINE

UNDOTBS2 _SYSSMU18$ ONLINE

UNDOTBS2 _SYSSMU19$ ONLINE

UNDOTBS2 _SYSSMU20$ ONLINE

11 rows selected www.2cto.com

SQL> show parameter undo

NAME TYPE VALUE

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

undo_management string AUTO

undo_retention integer 900

undo_tablespace string undotbs1

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