ORACLE 12C PDB 维护基础介绍

CDB和PDB是ORACLE 12C一个很亮的新特性,由于他们的引入导致传统的ORACLE数据库管理理念不少发生了改变,这里列举了部分最基本的cdb和pdb管理方式
cdb和pdb关系图

ORACLE 12C版本

SQL> select * from v$version;

BANNER                                                                               CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production              0
PL/SQL Release 12.1.0.1.0 - Production                                                    0
CORE    12.1.0.1.0      Production                                                        0
TNS for Linux: Version 12.1.0.1.0 - Production                                            0
NLSRTL Version 12.1.0.1.0 - Production                                                    0

启动关闭pdb

SQL> startup
ORACLE instance started.

Total System Global Area  597098496 bytes
Fixed Size                  2291072 bytes
Variable Size             272632448 bytes
Database Buffers          314572800 bytes
Redo Buffers                7602176 bytes
Database mounted.
Database opened.
SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           MOUNTED
         4 3872456618 PDB2                           MOUNTED

SQL> alter PLUGGABLE database pdb1 open;

Pluggable database altered.

SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           READ WRITE
         4 3872456618 PDB2                           MOUNTED

SQL> alter PLUGGABLE database pdb1 close;

Pluggable database altered.

SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           MOUNTED
         4 3872456618 PDB2                           MOUNTED

SQL> alter PLUGGABLE database all open;

Pluggable database altered.

SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           READ WRITE
         4 3872456618 PDB2                           READ WRITE

SQL> alter PLUGGABLE database all close;

Pluggable database altered.

SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           MOUNTED
         4 3872456618 PDB2                           MOUNTED

SQL> alter session set container=pdb1;

Session altered.

SQL> startup
Pluggable Database opened.
SQL>  select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         3 3313918585 PDB1                           READ WRITE

pdb的管理可以在cdb中进行也可以在pdb中进行,如果是cdb中进行,需要PLUGGABLE关键字,如果是pdb中直接和普通数据库一样

登录pdb

[oracle@xifenfei ~]$ lsnrctl status

LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 12-MAY-2013 08:07:02

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=xifenfei)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.1.0.1.0 - Production
Start Date                11-MAY-2013 18:30:54
Uptime                    0 days 13 hr. 36 min. 8 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/grid/product/12.1/network/admin/listener.ora
Listener Log File         /u01/app/grid/diag/tnslsnr/xifenfei/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=xifenfei)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=xifenfei)(PORT=5500))
(Security=(my_wallet_directory=/u01/oracle/12.1/db_1/admin/cdb/xdb_wallet))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM", status READY, has 1 handler(s) for this service...
Service "cdb" has 1 instance(s).
  Instance "cdb", status READY, has 1 handler(s) for this service...
Service "cdbXDB" has 1 instance(s).
  Instance "cdb", status READY, has 1 handler(s) for this service...
Service "pdb1" has 1 instance(s).
  Instance "cdb", status READY, has 1 handler(s) for this service...
Service "pdb2" has 1 instance(s).
  Instance "cdb", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@xifenfei ~]$ tnsping pdb1

TNS Ping Utility for Linux: Version 12.1.0.1.0 - Production on 12-MAY-2013 08:07:09

Copyright (c) 1997, 2013, Oracle.  All rights reserved.

Used parameter files:


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = xifenfei)
(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = pdb1)))
OK (20 msec)
[oracle@xifenfei ~]$ sqlplus sys/xifenfei@pdb1 as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Sun May 12 08:08:02 2013

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Advanced Analytics
and Real Application Testing options

SQL> show con_name;

CON_NAME
------------------------------
PDB1


[oracle@xifenfei ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Sun May 12 08:09:14 2013

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Advanced Analytics
and Real Application Testing options

SQL> alter session set container=pdb1;

Session altered.

SQL> show con_name;

CON_NAME
------------------------------
PDB1

pdb可以通过alter session container进入也可以直接通过tns方式登录

创建用户

SQL> show con_name;

CON_NAME
------------------------------
CDB$ROOT

SQL> select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

    CON_ID       DBID NAME                           OPEN_MODE
---------- ---------- ------------------------------ ----------
         2 4048821679 PDB$SEED                       READ ONLY
         3 3313918585 PDB1                           READ WRITE
         4 3872456618 PDB2                           MOUNTED

SQL> create user xff identified by xifenfei;
create user xff identified by xifenfei
            *
ERROR at line 1:
ORA-65096: invalid common user or role name


SQL> !oerr ora 65096
65096, 00000, "invalid common user or role name"
// *Cause:  An attempt was made to create a common user or role with a name
//          that wass not valid for common users or roles.  In addition to 
//          the usual rules for user and role names, common user and role 
//          names must start with C## or c## and consist only of ASCII 
//          characters.
// *Action: Specify a valid common user or role name.
//

SQL> create user c##xff identified by xifenfei;

User created.

SQL> SELECT USERNAME,CON_ID,USER_ID FROM CDB_USERS WHERE USERNAME='C##XFF';

USERNAME       CON_ID    USER_ID
---------- ---------- ----------
C##XFF              1        103
C##XFF              3        104

SQL> alter session set container=pdb1;

Session altered.

SQL> show con_name

CON_NAME
------------------------------
PDB1
SQL> create user xff identified by xifenfei;

User created.

SQL> create user c##abc identified by xifenfei;
create user c##abc identified by xifenfei
            *
ERROR at line 1:
ORA-65094: invalid local user or role name

创建用户默认的是container=all,在cdb中只能创建全局用户(c##开头),会在cdb和所有的pdb中创建该用户(但是pdb中的全局用户需要另外授权才能够在pdb中访问)。在pdb中只能创建的用户为本地用户

用户授权

SQL> grant connect to c##xff;

Grant succeeded.

SQL> select GRANTEE,con_id from cdb_ROLE_PRIVS where GRANTED_ROLE='CONNECT' AND GRANTEE='C##XFF';

GRANTEE                            CON_ID
------------------------------ ----------
C##XFF                                  1

SQL> grant resource to c##xff container=all;

Grant succeeded.

SQL>  select GRANTEE,con_id from cdb_ROLE_PRIVS where GRANTED_ROLE='RESOURCE' AND  GRANTEE='C##XFF';

GRANTEE                            CON_ID
------------------------------ ----------
C##XFF                                  1
C##XFF                                  3

用户授权默认情况下是只会给当前container,在cdb中也可以指定container=all,对所有open的pdb且存在该用户都进行授权

修改参数

SQL> alter system set open_cursors=500 container=all;

System altered.

SQL> conn sys/xifenfei@pdb1 as sysdba
Connected.
SQL> show parameter open_cursors;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
open_cursors                         integer     500
SQL>  alter system set open_cursors=100;
 alter system set open_cursors=100
*
ERROR at line 1:
ORA-01219: database or pluggable database not open: queries allowed on fixed
tables or views only


SQL> alter database open;

Database altered.

SQL> alter system set open_cursors=100;

System altered.

SQL>  show parameter open_cursors;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
open_cursors                         integer     100
SQL> conn / as sysdba
Connected.
SQL> show parameter open_cursors;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
open_cursors                         integer     500

这里可以看到在cdb中修改,pdb会继承进去;如果在pdb中修改会覆盖pdb从cdb中继承的参数含义

乱用_allow_resetlogs_corruption参数导致悲剧

一个朋友11.2.0.1的数据库因为断电,出现不能正常open问题,自己尝试恢复,折腾了几天,最后让我帮忙的时候错误如下

SQL> startup
ORACLE 例程已经启动。

Total System Global Area  778387456 bytes
Fixed Size                  1374808 bytes
Variable Size             545260968 bytes
Database Buffers          226492416 bytes
Redo Buffers                5259264 bytes
数据库装载完毕。
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00604: error occurred at recursive SQL level 1
ORA-01578: ORACLE data block corrupted (file # 1, block # 225)
ORA-01110: data file 1: 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'
进程 ID: 5964
会话 ID: 1144 序列号: 5

从启动的日志提示看初步判断就是悲剧了,因为根据经验值在11gr2版本中,该错误就是undo$(分析trace文件进步一确定是undo$),该block出现异常,数据库在启动的时候要扫描该表,把相关的回滚段给online起来,现在他异常了,数据库肯定无法正常启动
dbv检查数据库文件

F:\>dbv file='F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'

DBVERIFY: Release 11.2.0.1.0 - Production on 星期三 5月 22 11:06:00 2013

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - 开始验证: FILE = F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF
页 225 流入 - 很可能是介质损坏
Corrupt block relative dba: 0x004000e1 (file 1, block 225)
Fractured block found during dbv:
Data in bad block:
 type: 6 format: 2 rdba: 0x004000e1
 last change scn: 0x0000.00d65120 seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0xb98e0601
 check value in block header: 0xb307
 computed block checksum: 0xe8ae



DBVERIFY - 验证完成

检查的页总数: 134400
处理的页总数 (数据): 98226
失败的页总数 (数据): 0
处理的页总数 (索引): 14189
失败的页总数 (索引): 0
处理的页总数 (其他): 4178
处理的总页数 (段)  : 1
失败的总页数 (段)  : 0
空的页总数: 17806
标记为损坏的总页数: 1
流入的页总数: 1
加密的总页数        : 0
最高块 SCN            : 14045769 (0.14045769)

看到这里,可以确定坏块的存在,根据上面的提示,我们发现tailchk值不正确,应该是5120+06+01,而不该是b98e0601,通过bbed查看

BBED> p kcbh
struct kcbh, 20 bytes                       @0
   ub1 type_kcbh                            @0        0x06
   ub1 frmt_kcbh                            @1        0xa2
   ub1 spare1_kcbh                          @2        0x00
   ub1 spare2_kcbh                          @3        0x00
   ub4 rdba_kcbh                            @4        0x004000e1
   ub4 bas_kcbh                             @8        0x00d65120
   ub2 wrp_kcbh                             @12       0x0000
   ub1 seq_kcbh                             @14       0x01
   ub1 flg_kcbh                             @15       0x06 (KCBHFDLC, KCBHFCKV)
   ub2 chkval_kcbh                          @16       0x5ba9
   ub2 spare3_kcbh                          @18       0x0000

BBED> p tailchk
ub4 tailchk                                 @8188     0xb98e0601

进一步证明是tailchk异常导致,分析alert日志,数据库异常断电,然后启动的时候发现如下错误

Recovery of Online Redo Log: Thread 1 Group 2 Seq 431 Reading mem 0
  Mem# 0: F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\REDO02.LOG
RECOVERY OF THREAD 1 STUCK AT BLOCK 451 OF FILE 3
Aborting crash recovery due to error 1172
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_772.trc:
ORA-01172: 线程 1 的恢复停止在块 451 (在文件 3 中)
ORA-01151: 如果需要, 请使用介质恢复以恢复块和还原备份
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_772.trc:
ORA-01172: 线程 1 的恢复停止在块 451 (在文件 3 中)
ORA-01151: 如果需要, 请使用介质恢复以恢复块和还原备份
ORA-1172 signalled during: alter database open...
Tue May 21 14:27:29 2013
ALTER DATABASE RECOVER  datafile 3  
Media Recovery Start
Serial Media Recovery started
Recovery of Online Redo Log: Thread 1 Group 2 Seq 431 Reading mem 0
  Mem# 0: F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\REDO02.LOG
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_772.trc  (incident=112164):
ORA-00600: 内部错误代码, 参数: [3020], [3], [451], [12583363], [], [], [], [], [], [], [], []
ORA-10567: Redo is inconsistent with data block (file# 3, block# 451, file offset is 3694592 bytes)
ORA-10564: tablespace UNDOTBS1
ORA-01110: 数据文件 3: 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\UNDOTBS01.DBF'
ORA-10560: block type 'KTU UNDO BLOCK'
Media Recovery failed with error 600
ORA-283 signalled during: ALTER DATABASE RECOVER  datafile 3  ...

因为file# 3, block# 451和redo信息不一致,出现ora-600[3020]错误,而file# 3为undo文件,朋友从而设置undo_management=’manual’并设置了_allow_resetlogs_corruption=true,然后进行不完全恢复,从而出现了如下错误提示

Tue May 21 14:41:23 2013
SMON: enabling cache recovery
Corrupt block relative dba: 0x004000e1 (file 1, block 225)
Fractured block found during buffer read
Data in bad block:
 type: 6 format: 2 rdba: 0x004000e1
 last change scn: 0x0000.00d65120 seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0xb98e0601
 check value in block header: 0xb307
 computed block checksum: 0xe8ae
Reading datafile 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'
for corruption at rdba: 0x004000e1 (file 1, block 225)
Reread (file 1, block 225) found same corrupt data
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_4892.trc  (incident=120165):
ORA-01578: ORACLE 数据块损坏 (文件号 1, 块号 225)
ORA-01110: 数据文件 1: 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_4892.trc:
ORA-00604: 递归 SQL 级别 1 出现错误
ORA-01578: ORACLE 数据块损坏 (文件号 1, 块号 225)
ORA-01110: 数据文件 1: 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'
Errors in file f:\app\administrator\diag\rdbms\yfcloud\yfcloud\trace\yfcloud_ora_4892.trc:
ORA-00604: 递归 SQL 级别 1 出现错误
ORA-01578: ORACLE 数据块损坏 (文件号 1, 块号 225)
ORA-01110: 数据文件 1: 'F:\APP\ADMINISTRATOR\ORADATA\YFCLOUD\SYSTEM01.DBF'
Error 604 happened during db open, shutting down database
USER (ospid: 4892): terminating the instance due to error 604

从而的原因基本上可以从操作过程中了解到:数据库是因为file# 3 block# 451和redo不一致导致问题,而恢复的操作人员冲动的使用了_allow_resetlogs_corruption参数,从而使得数据库出现了不一致性,也就是导致file# 1 block# 225坏块的根本原因,针对这样的情况,完全没有到使用_allow_resetlogs_corruption隐含参数地步

使用bbed修改tailchk

BBED> p tailchk
ub4 tailchk                                 @8188     0xb98e0601

BBED> verify
DBVERIFY - Verification starting
FILE = system01.dbf
BLOCK = 225

Block 225 is corrupt
***
Corrupt block relative dba: 0x004000e1 (file 0, block 225)
Fractured block found during verification
Data in bad block -
 type: 6 format: 2 rdba: 0x004000e1
 last change scn: 0x0000.00d65120 seq: 0x1 flg: 0x06
 consistency value in tail: 0xb98e0601
 check value in block header: 0x5ba9, computed block checksum: 0x0
 spare1: 0x0, spare2: 0x0, spare3: 0x0
***


DBVERIFY - Verification complete

Total Blocks Examined         : 1
Total Blocks Processed (Data) : 0
Total Blocks Failing   (Data) : 0
Total Blocks Processed (Index): 0
Total Blocks Failing   (Index): 0
Total Blocks Empty            : 0
Total Blocks Marked Corrupt   : 1
Total Blocks Influx           : 2

BBED> m /x 01062051
 File: system01.dbf (0)
 Block: 226              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 01062051

 <32 bytes per line>

BBED> p tailchk
ub4 tailchk                                 @8188     0x51200601

BBED> sum apply
Check value for File 0, Block 226:
current = 0xb307, required = 0xb307

BBED> verify
DBVERIFY - Verification starting
FILE = system01.dbf
BLOCK = 225


DBVERIFY - Verification complete

Total Blocks Examined         : 1
Total Blocks Processed (Data) : 1
Total Blocks Failing   (Data) : 0
Total Blocks Processed (Index): 0
Total Blocks Failing   (Index): 0
Total Blocks Empty            : 0
Total Blocks Marked Corrupt   : 0
Total Blocks Influx           : 0

bbed修改block之后,数据库直接正常打开,完成数据库恢复任务,在这里很明显是因为错误的使用了_allow_resetlogs_corruption参数,屏蔽了redo前滚导致了相关的坏块,所以大家在数据库异常恢复的时候,需要知道各个参数的意义,而不要乱使用,很可能导致不可控结果

ksuapc : ORA-1033 foreground process starts before PMON

在11.2.0.1数据库中启动出现ksuapc : ORA-1033 foreground process starts before PMON错误

Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Picked latch-free SCN scheme 3
Using LOG_ARCHIVE_DEST_1 parameter default value as USE_DB_RECOVERY_FILE_DEST
Autotune of undo retention is turned on. 
IMODE=BR
ILAT =27
LICENSE_MAX_USERS = 0
SYS auditing is disabled
Starting up:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options.
Using parameter settings in server-side spfile /opt/oracle/product/11.2.0/dbhome_1/dbs/spfileora11bak.ora
System parameters with non-default values:
  processes                = 150
  nls_language             = "SIMPLIFIED CHINESE"
  nls_territory            = "CHINA"
  sga_target               = 1536M
  control_files            = "/opt/oracle/oradata/ora11bak/control01.ctl"
  control_files            = "/opt/oracle/flash_recovery_area/ora11bak/control02.ctl"
  db_block_size            = 8192
  compatible               = "11.2.0.0.0"
  db_recovery_file_dest    = "/opt/oracle/flash_recovery_area"
  db_recovery_file_dest_size= 3882M
  undo_tablespace          = "UNDOTBS1"
  remote_login_passwordfile= "EXCLUSIVE"
  db_domain                = ""
  dispatchers              = "(PROTOCOL=TCP) (SERVICE=ora11bakXDB)"
  audit_file_dest          = "/opt/oracle/admin/ora11bak/adump"
  audit_trail              = "DB"
  db_name                  = "ora11bak"
  open_cursors             = 300
  pga_aggregate_target     = 1595M
  diagnostic_dest          = "/opt/oracle"
Fri May 17 05:03:15 2013
ksuapc : ORA-1033 foreground process starts before PMON
Fri May 17 05:03:15 2013
ksuapc : ORA-1033 foreground process starts before PMON
Fri May 17 05:03:16 2013
ksuapc : ORA-1033 foreground process starts before PMON
Fri May 17 05:03:16 2013
ksuapc : ORA-1033 foreground process starts before PMON
Fri May 17 05:03:16 2013
ksuapc : ORA-1033 foreground process starts before PMON
Fri May 17 05:03:16 2013
ksuapc : ORA-1033 foreground process starts before PMON
…………

该错误的原因是数据库在启动过程中有前台进程连接数据库导致,该现象是数据库bug 8991997,该bug影响版本为:11.2.0.1/11.1.0.7,在11.2.0.1.1开始修复


一次侥幸的OSD-04016 O/S-Error异常恢复

一台数据库因为异常断电导致硬盘IO出现O/S-Error: (OS 23) 数据错误(循环冗余检查)错误,使得datafile 6无法完成实例恢复.使用dbv检查该数据文件也出现类似错误,尝试copy该文件,也出现了类似的错误.尝试dd拷贝完整,发现dd也只能拷贝81951个block.

Tue May 14 15:32:10 2013
Completed redo scan
 16941 redo blocks read, 1106 data blocks need recovery
Tue May 14 15:32:17 2013
Errors in file d:\oracle\product\10.2.0\admin\water\bdump\water_p002_1472.trc:
ORA-01115: IO error reading block from file 6 (block # 81951)
ORA-01110: data file 6: 'D:\ORACLE\PRODUCT\10.2.0\ORADATA\WATER\YD_DATA01.DBF'
ORA-27070: async read/write failed
OSD-04016: 异步 I/O 请求排队时出错。
O/S-Error: (OS 23) 数据错误(循环冗余检查)。

因为该数据库有一天前的备份,而且他们只要求恢复其中三张核心表的数据,通过分析数据字典,确定出来相关表的block均不在block 81951之上,也就是说,如果数据库只是该block异常了,可以通过跳过该block,从而copy相关block,来实现数据库恢复,因为是一个文件的中间部分异常了,所以决定使用dd来copy文件正常部分

dd if=D:\ORACLE\PRODUCT\10.2.0\ORADATA\WATER\YD_DATA01.DBF bs=8192 count=81951 of=h:\dd\yd_data01_1.dbf
dd if=D:\ORACLE\PRODUCT\10.2.0\ORADATA\WATER\YD_DATA01.DBF bs=8192  skip=81952   of=h:\dd\yd_data01_2.dbf

dd出来文件之后,因为我们跳过了block 81952(block 0 数据库为记录),所以我们需要通过dd来构造block 81952,并且把他们合并到一起

dd if=/dev/zero of=h:\dd\yd_data01_1.dbf seek=81951 bs=8192 count=1
dd if=h:\dd\yd_data01_2.dbf seek=81952 bs=8192 of=h:\dd\yd_data01_1.dbf 

然后使用dul工具抽出来客户需要的三张核心表的数据,恢复工作算完成。
针对本次恢复,如果需求是open数据库,通过设置隐含参数,bbed之类原则上也可以实现.
这次的恢复算是比较侥幸:1.客户有一天前的exp,只需要恢复三张核心表数据;2.三张表的数据恰好都不在损坏的block中;3.数据库就损坏了一个block.
如果出现不幸情况,那可能需要先硬盘恢复,然后数据库恢复,最后折腾数据.
总之再次提醒各位:数据库备份很重要,很重要.对于需求是不能丢失数据的系统备份,一定要rman的方式备份,千万别选择exp/expdp

关于ORACLE 11G密码大小写敏感猜想(USER$.SPARE4)

从11.1开始密码大小写敏感了,同时可以设置sec_case_sensitive_logon参数可以忽略大小写敏感。
通过朋友咨询的不设置sec_case_sensitive_logon参数让密码大小写不敏感的实验这篇文章疑惑,同时也感谢朋友让我学习到了新知识,我通过测试证明了如下结论:
1.password_versions的优先级大于sec_case_sensitive_logon
2.通过修改USER$.SPARE4为空实现了屏蔽ORACLE 11g密码大小写敏感

10g创建用户导出数据

SQL> create user ora10g identified by xifenfei;

User created.

SQL> grant connect to ora10g;

Grant succeeded.


C:\Documents and Settings\Administrator>expdp \"/ as sysdba \" DIRECTORY=exp_dp
DUMPFILE=chf.dmp schemas=ora10g

Export: Release 10.2.0.1.0 - Production on 星期三, 15 5月, 2013 22:59:45

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

连接到: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
启动 "SYS"."SYS_EXPORT_SCHEMA_01":  "/******** AS SYSDBA" DIRECTORY=exp_dp DUMPF
ILE=chf.dmp schemas=ora10g
正在使用 BLOCKS 方法进行估计...
处理对象类型 SCHEMA_EXPORT/TABLE/TABLE_DATA
使用 BLOCKS 方法的总估计: 0 KB
处理对象类型 SCHEMA_EXPORT/USER
处理对象类型 SCHEMA_EXPORT/ROLE_GRANT
处理对象类型 SCHEMA_EXPORT/DEFAULT_ROLE
处理对象类型 SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA
已成功加载/卸载了主表 "SYS"."SYS_EXPORT_SCHEMA_01"
******************************************************************************
SYS.SYS_EXPORT_SCHEMA_01 的转储文件集为:
  C:\CHF.DMP
作业 "SYS"."SYS_EXPORT_SCHEMA_01" 已于 23:00:19 成功完成

11g创建用户


SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE    11.2.0.3.0      Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production

SQL> show parameter logon

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
sec_case_sensitive_logon             boolean     TRUE
SQL> create user ora11g identified by xifenfei;

User created.

SQL> grant connect to ora11g;

Grant succeeded.

SQL> conn ora11g/xifenfei
Connected.
SQL> conn ora11g/XIFENFEI
ERROR:
ORA-01017: invalid username/password; logon denied


Warning: You are no longer connected to ORACLE.

这里证明,在sec_case_sensitive_logon=true的情况下,数据库密码是大小写敏感

导入10g创建用户dmp文件

[oracle@localhost ~]$ impdp '"/ as sysdba"' directory=exp_dp dumpfile=CHF.DMP 

Import: Release 11.2.0.3.0 - Production on Wed May 15 23:07:20 2013

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Master table "SYS"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYS"."SYS_IMPORT_FULL_01":  "/******** AS SYSDBA" directory=exp_dp dumpfile=CHF.DMP 
Processing object type SCHEMA_EXPORT/USER
Processing object type SCHEMA_EXPORT/ROLE_GRANT
Processing object type SCHEMA_EXPORT/DEFAULT_ROLE
Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA
Job "SYS"."SYS_IMPORT_FULL_01" successfully completed at 23:07:21

查询ora10g和ora11g用户区别

SQL> conn ora10g/xifenfei
Connected.
SQL> conn ora10g/XIFENFEI
Connected.
SQL> conn / as sysdba
Connected.
SQL>  select t.username,t.account_status,t.password_versions from dba_users t where t.username in ('ORA11G','ORA10G');

USERNAME                       ACCOUNT_STATUS                   PASSWORD
------------------------------ -------------------------------- --------
ORA11G                         OPEN                             10G 11G
ORA10G                         OPEN                             10G

SQL> select name,password,spare4 from SYS.USER$ t where name in ('ORA11G','ORA10G');

NAME                           PASSWORD                       SPARE4
------------------------------ ------------------------------ ----------------------------------------------------------------
ORA10G                         F3CF2F0CB35CB6CA
ORA11G                         559D84354181EB8E               S:BFE2625310D9382E9AEA6EE0AA2988E82C17B3EA23E3DAC23800490C2621

这里可以发现我们从低版本(10g)导入到11g中的用户登录是不区分大小写,而11g本身创建的用户是区分大小写,而他们的区别仅仅是在dba_users.password_versions中有不一样,跟踪到基表发现就是USER$.SPARE4列不一样(10g的该列为空).
猜想:password_versions的优先级大于sec_case_sensitive_logon这个参数

验证猜想
如果是password_versions的优先级大于sec_case_sensitive_logon那么,如果我修改了USER$.SPARE4,使得dba_users.password_versions变成和10g导入的库一样,是否就可以实现不区分密码大小写的问题,如果不缺乏证明:password_versions的优先级大于sec_case_sensitive_logon这个参数,反之失败.

SQL> update SYS.USER$ t set SPARE4='' where name='ORA11G';

1 row updated.

SQL> COMMIT;

Commit complete.


SQL> alter system flush shared_pool;

System altered.

SQL> conn ora11g/XIFENFEI
Connected.
SQL> conn ora11g/xifenfei
Connected.

由此得出两个结论:
1.password_versions的优先级大于sec_case_sensitive_logon
2.通过修改USER$.SPARE4为空实现了屏蔽ORACLE 11g密码大小写敏感