Oracle undo表空间切换
Oracle undo表空间切换
Oracle的AUM(Auto Undo Management)从出生以来就经常出现只扩展,不收缩(shrink)的情况(通常我们可以设置足够的UNDO表空间大小,然后取消其自动扩展属性),在实际的环境中遇到undo表空间为断上涨，报警短信不断。
1.确认文件
SQL> select file_name,bytes/1024/1024 from dba_data_files
2 where tablespace_name like 'UNDOTBS1';
FILE_NAME
--------------------------------------------------------------------------------
BYTES/1024/1024
---------------
+ORADG/danaly/datafile/undotbs1.265.600173875
27810
|
2.检查UNDO Segment状态
SQL> select usn,xacts,rssize/1024/1024/1024,hwmsize/1024/1024/1024,shrinks
2 from v$rollstat order by rssize;
USN XACTS RSSIZE/1024/1024/1024 HWMSIZE/1024/1024/1024 SHRINKS
---------- ---------- --------------------- ---------------------- ----------
0 0 .000358582 .000358582 0
2 0 .071517944 .071517944 0
3 0 .13722229 .13722229 0
9 0 .236984253 .236984253 0
10 0 .625144958 .625144958 0
5 1 1.22946167 1.22946167 0
8 0 1.27175903 1.27175903 0
4 1 1.27895355 1.27895355 0
7 0 1.56770325 1.56770325 0
1 0 2.02474976 2.02474976 0
6 0 2.9671936 2.9671936 0
11 rows selected.
|
3.创建新的UNDO表空间
SQL> create undo tablespace undotbs2; Tablespace created. |
4.切换UNDO表空间为新的UNDO表空间
SQL> alter system set undo_tablespace=undotbs2 scope=both; System altered. |
此处使用spfile需要注意，以前曾经记录过这样一个案例:Oracle诊断案例-Spfile案例一则
5.等待原UNDO表空间所有UNDO SEGMENT OFFLINE
SQL> select usn,xacts,status,rssize/1024/1024/1024,hwmsize/1024/1024/1024,shrinks
2 from v$rollstat order by rssize;
USN XACTS STATUS RSSIZE/1024/1024/1024 HWMSIZE/1024/1024/1024 SHRINKS
---------- ---------- --------------- --------------------- ---------------------- ----------
14 0 ONLINE .000114441 .000114441 0
19 0 ONLINE .000114441 .000114441 0
11 0 ONLINE .000114441 .000114441 0
12 0 ONLINE .000114441 .000114441 0
13 0 ONLINE .000114441 .000114441 0
20 0 ONLINE .000114441 .000114441 0
15 1 ONLINE .000114441 .000114441 0
16 0 ONLINE .000114441 .000114441 0
17 0 ONLINE .000114441 .000114441 0
18 0 ONLINE .000114441 .000114441 0
0 0 ONLINE .000358582 .000358582 0
USN XACTS STATUS RSSIZE/1024/1024/1024 HWMSIZE/1024/1024/1024 SHRINKS
---------- ---------- --------------- --------------------- ---------------------- ----------
6 0 PENDING OFFLINE 2.9671936 2.9671936 0
12 rows selected.
|
再看:
11:32:11 SQL> /
USN XACTS STATUS RSSIZE/1024/1024/1024 HWMSIZE/1024/1024/1024 SHRINKS
---------- ---------- --------------- --------------------- ---------------------- ----------
15 1 ONLINE .000114441 .000114441 0
11 0 ONLINE .000114441 .000114441 0
12 0 ONLINE .000114441 .000114441 0
13 0 ONLINE .000114441 .000114441 0
14 0 ONLINE .000114441 .000114441 0
20 0 ONLINE .000114441 .000114441 0
16 0 ONLINE .000114441 .000114441 0
17 0 ONLINE .000114441 .000114441 0
18 0 ONLINE .000114441 .000114441 0
19 0 ONLINE .000114441 .000114441 0
0 0 ONLINE .000358582 .000358582 0
11 rows selected.
Elapsed: 00:00:00.00
|
6.删除原UNDO表空间
11:34:00 SQL> drop tablespace undotbs1 including contents; Tablespace dropped. Elapsed: 00:00:03.13 |
以下是自己实际操作;
-- 操作步骤
1.创建undo表空间
create undo tablespace undotbs2 datafile '/dev/vgdata01/rlv_ora_log11';
alter tablespace undotbs2 add datafile '/dev/vgdata01/rlv_ora_log12';
alter tablespace undotbs2 add datafile '/dev/vgdata01/rlv_ora_log13';
2.切换undo表空间
alter system set undo_tablespace=undotbs2 scope=both;
3.删除原表空间
drop tablespace undotbs1 including contents;
4.原表空间及数据文件：
/dev/vgdata01/rlv_ora_rbs01 UNDOTBS1
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