分类目录归档：ORA-xxxxx

ORA-01578坏块解决(1)

发表于 2011 年 8 月 15 日 由 惜分飞
一、创建测试表
SQL> create table t_rep as
2  select * from all_objects;
Table created.
SQL> select count(*) from  t_rep;
COUNT(*)
———-
49857
二、使用bbed修改数据块
三、错误现象
1、sqlplus窗口
SQL> select count(*) from  t_rep;
select count(*) from  t_rep
*
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 6, block # 1477)
ORA-01110: data file 6: ‘/opt/oracle/oradata/test/xifenfei01.dbf’
2、alert.log文件中
Sun Aug 14 22:01:14 2011
Hex dump of (file 6, block 1477) in trace file /opt/oracle/admin/test/udump/test_ora_10785.trc
Corrupt block relative dba: 0x018005c5 (file 6, block 1477)
Bad check value found during buffer read
Data in bad block:
type: 6 format: 2 rdba: 0x018005c5
last change scn: 0×0000.001328ef seq: 0×2 flg: 0×04
spare1: 0×0 spare2: 0×0 spare3: 0×0
consistency value in tail: 0x28ef0602
check value in block header: 0×493
computed block checksum: 0x44b9
Reread of rdba: 0x018005c5 (file 6, block 1477) found same corrupted data
Sun Aug 14 22:01:15 2011
Corrupt Block Found
TSN = 6, TSNAME = XFF
RFN = 6, BLK = 1477, RDBA = 25167301
OBJN = 52727, OBJD = 52728, OBJECT = T_REP, SUBOBJECT =
SEGMENT OWNER = SYS, SEGMENT TYPE = Table Segment
四、验证是否真的坏块
1、dbv验证
[oracle@ECP-UC-DB1 ~]$ dbv file =/opt/oracle/oradata/test/xifenfei01.dbf
DBVERIFY: Release 10.2.0.4.0 – Production on Sun Aug 14 22:08:37 2011
Copyright (c) 1982, 2007, Oracle.  All rights reserved.
DBVERIFY – Verification starting : FILE = /opt/oracle/oradata/test/xifenfei01.dbf
Page 1477 is marked corrupt
Corrupt block relative dba: 0x018005c5 (file 6, block 1477)
Bad check value found during dbv:
Data in bad block:
type: 6 format: 2 rdba: 0x018005c5
last change scn: 0×0000.001328ef seq: 0×2 flg: 0×04
spare1: 0×0 spare2: 0×0 spare3: 0×0
consistency value in tail: 0x28ef0602
check value in block header: 0×493
computed block checksum: 0x44b9
DBVERIFY – Verification complete
Total Pages Examined         : 2560
Total Pages Processed (Data) : 1371
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 48
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 1140
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 0
Highest block SCN            : 1256043 (0.1256043)
2、rman验证
RMAN> backup check logical validate datafile 6;
Starting backup at 2011-08-14 22:09:51
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=157 devtype=DISK
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00006 name=/opt/oracle/oradata/test/xifenfei01.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2011-08-14 22:09:53
RMAN> exit
Recovery Manager complete.
[oracle@ECP-UC-DB1 ~]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.4.0 – Production on Sun Aug 14 22:10:00 2011
Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL>  select file#,block#,blocks from v$database_block_corruption;SQL> exec dbms_repair.skip_corrupt_blocks(‘SYS’,’T_REP’);
FILE#     BLOCK#     BLOCKS
———- ———- ———-
6       1477          1
五、跳过坏块读取其他数据
SQL> exec dbms_repair.skip_corrupt_blocks(‘SYS’,’T_REP’);
PL/SQL procedure successfully completed.
SQL> select skip_corrupt from dba_tables where table_name=’T_REP’;
SKIP_COR
——–
ENABLED
SQL> select count(*) from t_rep;
COUNT(*)
———-
49794
说明：数据发生丢失6号文件的1477块中的数据丢失
发表在 ORA-xxxxx, Oracle备份恢复 | 标签为 | 一条评论

物化视图on prebuilt table

发表于 2011 年 8 月 14 日 由 惜分飞

1、ORA-12059
执行语句：
CREATE MATERIALIZED VIEW mv_t2
on prebuilt TABLE
AS
SELECT * FROM SCOTT.emp

错误提示：
ORA-12059: prebuilt table “CHF”.”MV_T2″ does not exist

错误原因：
物化视图对应的表不存在（物化视图需要和表同名，结构相同）

解决方法：
CREATE TABLE mv_t2 AS
SELECT * FROM scott.emp WHERE 1=0;

2、ORA-23413
执行语句：
CREATE MATERIALIZED VIEW mv_t2
on prebuilt TABLE
WITH REDUCED PRECISION
refresh FAST on demand
AS
SELECT * FROM SCOTT.emp

错误提示：
ORA-23413: table “SCOTT”.”EMP” does not have a materialized view log

错误原因：
使用fast模式刷新物化视图，需要有物化视图日志

解决方法：
1）创建物化视图日志
CREATE MATERIALIZED VIEW LOG ON scott.emp ;
2）刷新模式改为force，其实实质是采用了complete刷新模式

3、ORA-12058
执行语句（mv log是基于rowid，表无主键）
CREATE MATERIALIZED VIEW mv_t2
on prebuilt TABLE
WITH REDUCED PRECISION
refresh FAST on DEMAND
WITH ROWID
AS
SELECT * FROM SCOTT.emp

错误提示：
ORA-12058: materialized view cannot use prebuilt table

错误原因：
fast刷新模式不能基于rowid进行

解决方法：
1）删除mv log，表添加主键，采用基于主键模式重新建mv log和物化视图
DROP MATERIALIZED VIEW mv_t1;
ALTER TABLE mv_t2 ADD PRIMARY KEY (EMPNO);
CREATE MATERIALIZED VIEW LOG ON scott.emp;
CREATE MATERIALIZED VIEW mv_t2
on prebuilt TABLE
WITH REDUCED PRECISION
refresh FAST on DEMAND
–WITH ROWID
AS
SELECT * FROM SCOTT.emp;

2）刷新模式改为force，其实实质是采用了complete刷新模式

4、总结
1）在执行创建物化视图之前，需要先创建同名、同结构表
2）如果使用fast模式刷新（疑惑在线重定义可以通过rowid实现，为什么直接通过物化视图就不可以），物化视图同表需要主键，需要物化视图日志
3）通过drop mv，发现同名表还存在，和on prebuilt table本质区别

发表在 ORA-xxxxx | 评论关闭

ORA-01012: not logged on

发表于 2011 年 8 月 4 日 由 惜分飞

今天接到现场反馈，数据库出现ORA-01012: not logged on错误提示，这个问题上次也出现过一次，当时按照网上说的方法，直接重启数据库了，问题解决了，同时也导致因为数据库重启，现场破坏，而alert日志中无任何异常信息，所以不知从何处下手分析。这次我上数据库准备查看时，发现数据库已经正常，监控也显示正常，说明数据库已经恢复正常。从此我推理这个问题应该是外部因素导致，而不是数据库本身的bug，从而决定要找出该问题的原因来。有个重要的因素，该数据库是我几个月前因为undo损坏做过恢复的，查看相关参数，发现processes是默认值150，是不是该值导致的不敢肯定，因为一般process超了会报ORA-00020错误，而这次只有ORA-01012。但是心中还是没有底，总感觉这个的可能性最大，于是想通过试验来证实下自己的想法
1、数据库版本（10g结果相同）
SQL> select * from v$version where rownum=1;

BANNER
—————————————————————-
Oracle9i Enterprise Edition Release 9.2.0.4.0 – Production

2、创建pfile，修改processes，重启数据库，查看processes值
SQL> select name,value from v$parameter where name=’processes’;

NAME VALUE
——————– ——————–
processes 30

3、查看系统processes数量
SQL> select count(*) from v$process;

COUNT(*)
———-
13

4、添加数据库连接数（为了增加process数目）
[oracle@localhost ~]$ sqlplus chf/xifenfei

SQL*Plus: Release 9.2.0.4.0 – Production on Wed Jul 27 23:11:50 2011

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 – Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 – Production

SQL> !

5、重复3和4，发现当process数量为29时出现激动人心一幕
5.1)继续访问数据库
[oracle@localhost ~]$ sqlplus system/xifenfei

SQL*Plus: Release 9.2.0.4.0 – Production on Wed Jul 27 23:12:06 2011

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

ERROR:
ORA-00020: maximum number of processes (%s) exceeded

Enter user-name:

5.2)使用其他用户访问
[oracle@localhost ~]$ sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 – Production on Wed Jul 27 23:12:49 2011

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

SQL> conn / as sysdba
Connected to an idle instance.
SQL> select * from dual;
select * from dual
*
ERROR at line 1:
ORA-01012: not logged on

SQL> conn chf/xifenfei
ERROR:
ORA-00020: maximum number of processes (%s) exceeded

[oracle@localhost ~]$ sqlplus “/ as sysdba”

SQL*Plus: Release 9.2.0.4.0 – Production on Wed Jul 27 23:29:52 2011

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected.
SQL> select * from dual;
select * from dual
*
ERROR at line 1:
ORA-01012: not logged on
现象说明：
1)终于发现了ORA-01012错误，期待了很久。发现只有当sys登录系统，对数据库进行查询或者操作之时才会出现ORA-01012，其他用户只要一登录数据库就会提示ORA-00020错误。

2)当process达到数据库最大限时，sysdba登录系统是也显示不正常
2.1）当使用sqlplus “/ as sysdba”登录时，缺少：
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 – Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 – Production
2.2）当使用conn / as sysdba登录时，提示为：
Connected to an idle instance.

发表在 ORA-xxxxx | 标签为 | 2 条评论