How To resize undo tablespace in Oracle

2019年10月2日 146次阅读 来源: 花菜土豆粉

参考MOS文章How to Shrink the datafile of Undo Tablespace (文档 ID 268870.1)

操作步骤如下

  • Create a new undo tablespace with a smaller size:
SQL> create undo tablespace UNDO_RBS1 datafile 'undorbs1.dbf' size <new size>;
  • Set the new tablespace as the undo tablespace to be used:
SQL> alter system set undo\_tablespace=undo_rbs1;
  • Drop the old undo tablespace:
SQL> drop tablespace undo_rbs0 including contents.

可能碰到的问题

如果要drop的undo tablespace还有active事务的undo信息，那么需要等到事务结束之后，才能成功运行drop操作，否则会抛出ORA-30013: undo tablespace ‘%s’ is currently in use错误。一般的做法是，重启一次数据库，这样就可以确保所有事物使用的都是新建的undo tablespace。

通过以下sql可以查看当前系统中undo segment的情况：

SQL> select owner,segment_name,tablespace_name
     from dba_rollback_segs order by 3;

OWNER  SEGMENT_NAME                   TABLESPACE_NAME
------ ------------------------------ ------------------------------
PUBLIC _SYSSMU1$                      RBS
PUBLIC _SYSSMU2$                      RBS
PUBLIC _SYSSMU3$                      RBS
PUBLIC _SYSSMU5$                      RBS
PUBLIC _SYSSMU7$                      RBS
PUBLIC _SYSSMU9$                      RBS
PUBLIC _SYSSMU10$                     RBS
PUBLIC _SYSSMU8$                      RBS
PUBLIC _SYSSMU6$                      RBS
PUBLIC _SYSSMU4$                      RBS
SYS    SYSTEM                         SYSTEM
PUBLIC _SYSSMU11$                     UNDO_RBS1
PUBLIC _SYSSMU12$                     UNDO_RBS1
PUBLIC _SYSSMU13$                     UNDO_RBS1
PUBLIC _SYSSMU14$                     UNDO_RBS1
PUBLIC _SYSSMU15$                     UNDO_RBS1
PUBLIC _SYSSMU16$                     UNDO_RBS1
PUBLIC _SYSSMU17$                     UNDO_RBS1
PUBLIC _SYSSMU18$                     UNDO_RBS1
PUBLIC _SYSSMU19$                     UNDO_RBS1
PUBLIC _SYSSMU20$                     UNDO_RBS1
    原文作者：花菜土豆粉
    原文地址: https://segmentfault.com/a/1190000000594057
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
点赞