Oracle重建undo表空间

在日常管理过程中，我们有时会遇到需要重建undo表空间的情况。

重建undo表空间可以用来消减undo大小。重建参考如下步骤：

1 首先创建APPS_UNDOTS2表空间

sqlplus /nolog    conn / as sysdba
SQL> create undo tablespace APPS_UNDOTS2 datafile '/data/rbs99.dbf'size 100M extent management local;
SQL> shutdown immediate;

2 修改pfile中undo_tablespace参数

vi $ORACLE_HOME/dbs/initprod.ora
---> undo_tablespace=APPS_UNDOTS2

3 删除、重建APPS_UNDOTS1

SQL> startup
SQL> drop tablespace APPS_UNDOTS1 including contents and datafiles;
SQL> create undo tablespace APPS_UNDOTS1 datafile
     ''/data/rbs01.dbf'size 2000M ,
     ''/data/rbs02.dbf'size 2000M ,
     ''/data/rbs03.dbf'size 2000M ,
     ''/data/rbs04.dbf'size 2000M ,
     ''/data/rbs05.dbf'size 2000M ,
     ''/data/rbs06.dbf'size 2000M
     extent management local;
SQL> shutdown immediate;

4 修改pfile中undo_tablespace参数

vi $ORACLE_HOME/dbs/initprod.ora
---> undo_tablespace=APPS_UNDOTS1

5 删除APPS_UNDOTS2

SQL> startup 
SQL> drop tablespace APPS_UNDOTS2 including contents and datafiles;