月归档：十月 2013

因RAC的undo_management参数不一致导致数据库mount报ORA-01105 ORA-01606

发表于 2013 年 10 月 27 日由惜分飞

环境Linux 5.8 10.2.0.5 RAC,两个节点只能一个节点mount,如果尝试mount另外节点就报ORA-01105和ORA-01606错误
数据库版本

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production
CORE    10.2.0.5.0      Production
TNS for Linux: Version 10.2.0.5.0 - Production
NLSRTL Version 10.2.0.5.0 - Production

crs资源情况

[oracle@node1 dbs]$ $ORA_CRS_HOME/bin/crs_stat -t
Name           Type           Target    State     Host        
------------------------------------------------------------
ora....D1.inst application    OFFLINE   OFFLINE               
ora....D2.inst application    ONLINE    ONLINE    node2       
ora.PROD.db    application    ONLINE    ONLINE    node2       
ora....SM1.asm application    ONLINE    ONLINE    node1       
ora....E1.lsnr application    ONLINE    ONLINE    node1       
ora.node1.gsd  application    ONLINE    ONLINE    node1       
ora.node1.ons  application    ONLINE    ONLINE    node1       
ora.node1.vip  application    ONLINE    ONLINE    node1       
ora....SM2.asm application    ONLINE    ONLINE    node2       
ora....E2.lsnr application    ONLINE    ONLINE    node2       
ora.node2.gsd  application    ONLINE    ONLINE    node2       
ora.node2.ons  application    ONLINE    ONLINE    node2       
ora.node2.vip  application    ONLINE    ONLINE    node2

节点1 mount报错

SQL> startup
ORACLE instance started.
 
Total System Global Area  171966464 bytes
Fixed Size                  2094832 bytes
Variable Size             113248528 bytes
Database Buffers           50331648 bytes
Redo Buffers                6291456 bytes
ORA-01105: mount is incompatible with mounts by other instances
ORA-01606: gc_files_to_locks not identical to that of another mounted instance

Error:    ORA 1105 
Text:     mount is incompatible with mounts by other instances 
-------------------------------------------------------------------------------
Cause:  An attempt was made to mount the database, but another instance has already mounted 
        a database by the same name, and the mounts are not compatible.
        dditional messages will accompany this message to report why the mounts are incompatible.
Action:  See the accompanying messages for the appropriate action to take.

Error:  ORA 1606 
Text:   GC_FILES_TO_LOCKS not identical to that of another mounted instance 
-------------------------------------------------------------------------------
Cause:  The initialization parameter GC_FILES_TO_LOCKS is not the same as 
        another instance mounted in parallel mode.
        This parameter must be the same as that for all shared instances.
Action: Modify the parameter to be compatible with the other instances, then 
        shut down and restart the instance.

根据这个错误提示，查询两个节点的gc_files_to_locks参数，均为空值(默认值),也就是值相同

SQL> show parameter gc_files_to_locks;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
gc_files_to_locks                    string

检查两个节点的gc相关隐含参数,发现所有值也均一致

NAME                           DESCRIPTION                                                           VALUE  
------------------------------ --------------------------------------------------------------------- -------
_gc_affinity_limit             dynamic affinity limit                                                50     
_gc_affinity_minimum           dynamic affinity minimum activity per minute                          6000   
_gc_affinity_time              if non zero, enable dynamic object affinity                           10     
_gc_async_memcpy               if TRUE, use async memcpy                                             FALSE  
_gc_check_bscn                 if TRUE, check for stale blocks                                       TRUE   
_gc_coalesce_recovery_reads    if TRUE, coalesce recovery reads                                      TRUE   
_gc_defer_time                 how long to defer down converts for hot buffers                       3      
_gc_dissolve_undo_affinity     if TRUE, dissolve undo affinity after an offline                      FALSE  
_gc_dynamic_affinity_locks     if TRUE, get dynamic affinity locks                                   TRUE   
_gc_element_percent            global cache element percent                                          103    
_gc_global_lru                 turn global lru off, make it automatic, or turn it on                 AUTO   
_gc_initiate_undo_affinity     if TRUE, initiate undo affinity after an online                       TRUE   
_gc_integrity_checks           set the integrity check level                                         1      
_gc_keep_recovery_buffers      if TRUE, make recovery buffers current                                TRUE   
_gc_latches                    number of latches per LMS process                                     8      
_gc_maximum_bids               maximum number of bids which can be prepared                          0      
_gcs_fast_reconfig             if TRUE, enable fast reconfiguration for gcs locks                    TRUE   
_gcs_latches                   number of gcs resource hash latches to be allocated per LMS process   64     
_gcs_pkey_history              number of pkey remastering history                                    4000   
_gcs_process_in_recovery       if TRUE, process gcs requests during instance recovery                TRUE   
_gcs_resources                 number of gcs resources to be allocated                                      
_gcs_shadow_locks              number of pcm shadow locks to be allocated                                   
_gc_statistics                 if TRUE, kcl statistics are maintained                                TRUE   
_gcs_testing                   GCS testing parameter                                                 0      
_gc_tsn_undo_affinity          if TRUE, use TSN undo affinity                                        TRUE   
_gc_undo_affinity              if TRUE, enable dynamic undo affinity                                 TRUE   
_gc_undo_affinity_locks        if TRUE, get affinity locks for undo                                  TRUE   
_gc_use_cr                     if TRUE, allow CR pins on PI and WRITING buffers                      TRUE   
_gc_vector_read                if TRUE, vector read current buffers                                  TRUE

仔细对比数据库参数，发现undo异常

--节点1
SQL>  show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      MANUAL
undo_retention                       integer     900
undo_tablespace                      string      SYSTEM


--节点2
SQL>  show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1

这里已经明确，因为两个节点的undo_*相关参数配置不正确，导致数据库只能一个节点mount。进一步定位问题发现，原来是因为dba粗心在编辑节点1的参数文件的时候把undo_*相关的参数给弄丢了,从而数据库使用了默认值undo_management=manual,undo_tablespace=system

发表在 ORA-xxxxx | 标签为 ORA-01105, ORA-01606 | 评论关闭

win平台rman备份和删除dg备库归档日志脚本

发表于 2013 年 10 月 26 日由惜分飞

总觉得使用windows跑oracle是不靠谱的事情,可以这个世界上总有很多人喜欢做类似这样的事情,对于数据库比较常见的两件事情:rman和删除dg备库归档日志,在linux/unix平台上使用shell实现很简单,可是跑到win里面,就变的烦了,不是因为其麻烦,而是因为用的人少,不知道怎么下手处理该事情,我编写了简单的实现初级功能的win下面rman备份和删除备库归档日志脚本,供大家参考,也更加欢迎朋友提出来更加好的处理方法(win是真心的不懂)
rman备份脚本

--backup_oracle.bat文件
rman target / cmdfile=D:\backup\rman\backup_db.rman 
log=d:/backup/rman/logfile/rmanlog%date:~0,4%%date:~5,2%%date:~8,2%.log

--backup_db.rman文件
CONFIGURE RETENTION POLICY TO REDUNDANCY = 2;
CONFIGURE DEVICE TYPE DISK PARALLELISM 2;
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
backup filesperset = 5 as compressed backupset database format 'd:/backup/rman/full_%U.rman';
sql 'alter system archive log current';
backup  filesperset = 50 as compressed backupset archivelog  all format 'd:/backup/rman/arch_%U.rman'  delete input;
DELETE noprompt OBSOLETE;
crosscheck backup;
delete noprompt expired backup;
backup  format 'd:/backup/rman/ctl_%U.rman' current controlfile;
backup spfile format 'd:/backup/rman/spfile_%U.rman' ;
exit;

backup_oracle.bat文件加入到计划任务即可

删除dg备库归档日志(已经应用)

--delete_dg_archivelog.bat
rem 注意修改 部署目录
cd D:\win_xifenfei
d:
rem 注意delete_archive.sql 查询是否有记录

echo delete archivelog staring > delete_archivelog.bak
sqlplus / as sysdba @delete_archive.sql
echo rman target / cmdfile=rman_checkcross.rman>>delete_archivelog.bat 
delete_archivelog.bat >>delete_dg_archivelog_%DATE:~0,4%%DATE:~5,2%%DATE:~8,2%".log
exit

--delete_archive.sql
set lines 150
col name for a150
set pagesize 0 feedback off verify off heading off echo off
spool delete_archivelog.bat
select 'del '||name from v$archived_log where APPLIED='YES' AND NAME IS NOT NULL and DEST_ID=1;
spool off
exit;

--rman_checkcross.rman
crosscheck archivelog all;
delete noprompt expired archivelog all;
exit

delete_dg_archivelog.bat加入到计划任务即可

发表在 Data Guard | 评论关闭

db_block_checksum实质是通过flg_kcbh来控制block checksum

发表于 2013 年 10 月 20 日由惜分飞

db_block_checksum 用于DBWn和direct loader数据块写入到磁盘时，基于块内的所有字节计算得出一个校验值并将其写入块头。在该参数设置为typical和full时，当读入时候重新计算校验和写出时候的校验对比，如果不同则认为是块损坏。如果设置为FULL模式,则基于update/delete应用程序语句级别的改变发生后，校验值会被重新计算并写入。同时对于日志块，在写入之前，同样会生产校验值并写入到块头。该参数主要是防止IO硬件和IO子系统的错误。
这里提示我们是在系统参数级别使用db_block_checksum来控制block是否进行验证，那在block本身级别，是否有类似的值来控制，实现对block值的checksum？通过dump结合bbed给出相关答案
db_block_checksum为TYPICAL测试

CDB_CDB$ROOT@SYS> show parameter db_block_checksum;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_block_checksum                    string      TYPICAL
CDB_CDB$ROOT@SYS> conn / as sysdba
已连接。
CDB_CDB$ROOT@SYS> alter session set container=pdb;

会话已更改。

CDB_CDB$ROOT@SYS> alter database open;

数据库已更改。

CDB_CDB$ROOT@SYS> alter session set current_schema=chf;

会话已更改。

CDB_CDB$ROOT@SYS> create table t_xifenfei(id number,name varchar2(100));

表已创建。

CDB_CDB$ROOT@SYS> insert into t_xifenfei values(1,'www.xifenfei.com');

已创建 1 行。

CDB_CDB$ROOT@SYS> alter system checkpoint;

系统已更改。

CDB_CDB$ROOT@SYS>  select dbms_rowid.rowid_relative_fno(rowid) file_no,
2  dbms_rowid.rowid_block_number(rowid) block_no  from t_xifenfei;

   FILE_NO   BLOCK_NO
---------- ----------
         9      19229

CDB_CDB$ROOT@SYS> SELECT NAME FROM V$DATAFILE WHERE FILE#=9;

NAME
---------------------------------------------------------------------
E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF

dump 该block

buffer tsn: 3 rdba: 0x02404b1d (9/19229)
scn: 0xb8c.3c232935 seq: 0x01 flg: 0x06 tail: 0x29350601
frmt: 0x02 chkval: 0xe08b type: 0x06=trans data
Hex dump of block: st=0, typ_found=1

tab 0, row 0, @0x1f81
tl: 23 fb: --H-FL-- lb: 0x1  cc: 2
col  0: [ 2]  c1 02
col  1: [16]  77 77 77 2e 78 69 66 65 6e 66 65 69 2e 63 6f 6d
end_of_block_dump
End dump data blocks tsn: 3 file#: 9 minblk 19229 maxblk 19229

这里可以看到因为db_block_checksum=TYPICAL，因此插入记录的时候，dump block发现flg: 0×06 和 chkval: 0xe08b

使用bbed查看相关记录
补充:在win系统中,bbed查看block和block num相差1

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        0x02404b1d
   ub4 bas_kcbh                             @8        0x3c232935
   ub2 wrp_kcbh                             @12       0x0b8c
   ub1 seq_kcbh                             @14       0x01
   ub1 flg_kcbh                             @15       0x06 (KCBHFDLC, KCBHFCKV)
   ub2 chkval_kcbh                          @16       0xe08b
   ub2 spare3_kcbh                          @18       0x0000

通过对比bbed和dump出来数据，可以得出flg: 0×06(flg_kcbh),chkval: 0xe08b(chkval_kcbh)

使用bbed修改block验证chkval_kcbh
提问：在使用bbed修改block的时候，一般都需要使用sum apply 处理下，为什么呢？

BBED> d /v
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19230   Offsets: 8165 to 8191  Dba:0x00000000
-------------------------------------------------------
 2c010202 c1021077 77772e78 6966656e l ,...?.www.xifen
 6665692e 636f6d01 063529            l fei.com..5)

 <16 bytes per line>

--没有修改任何值，sum的current和required值相同，而且和chkval_kcbh也相同
BBED> sum
Check value for File 0, Block 19230:
current = 0xe08b, required = 0xe08b

--尝试修改值
BBED> m /x 78 offset 8173
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19230            Offsets: 8173 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 78772e78 6966656e 6665692e 636f6d01 063529

 <32 bytes per line>

BBED> d /v offset 8165
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19230   Offsets: 8165 to 8191  Dba:0x00000000
-------------------------------------------------------
 2c010202 c1021077 78772e78 6966656e l ,...?.wxw.xifen
 6665692e 636f6d01 063529            l fei.com..5)

 <16 bytes per line>

--发现current<>required
BBED> sum
Check value for File 0, Block 19230:
current = 0xe08b, required = 0xef8b

--apply把current修改为required值
BBED> sum apply
Check value for File 0, Block 19230:
current = 0xef8b, required = 0xef8b

--发现chkval_kcbh也修改为了required值
BBED> p kcbh.chkval_kcbh
ub2 chkval_kcbh                             @16       0xef8b

通过这里可以发现，在flg_kcbh含(KCBHFCKV)的情况下，如果block发生改变，则运行sum apply之后chkval_kcbh也发生改变

继续dump block

buffer tsn: 3 rdba: 0x02404b1d (9/19229)
scn: 0xb8c.3c232935 seq: 0x01 flg: 0x06 tail: 0x29350601
frmt: 0x02 chkval: 0xef8b type: 0x06=trans data
Hex dump of block: st=0, typ_found=1


tab 0, row 0, @0x1f81
tl: 23 fb: --H-FL-- lb: 0x1  cc: 2
col  0: [ 2]  c1 02
col  1: [16]  77 78 77 2e 78 69 66 65 6e 66 65 69 2e 63 6f 6d
end_of_block_dump
End dump data blocks tsn: 3 file#: 9 minblk 19229 maxblk 19229

证明上述结论正确:dump.flg=bbed.flg_kcbh，dump.chkval=bbed.chkval_kcbh

db_block_checksum为FALSE测试

CDB_CDB$ROOT@SYS> alter system set db_block_checksum=false;

系统已更改。

CDB_CDB$ROOT@SYS> drop table t_xifenfei_new purge;

表已删除。

CDB_CDB$ROOT@SYS> alter session set current_schema=chf;

会话已更改。

CDB_CDB$ROOT@SYS>  create table t_xifenfei_new(id number,name varchar2(100));

表已创建。

CDB_CDB$ROOT@SYS>  insert into t_xifenfei_new values(1,'www.orasos.com');

已创建 1 行。

CDB_CDB$ROOT@SYS> commit;

提交完成。

CDB_CDB$ROOT@SYS>  select dbms_rowid.rowid_relative_fno(rowid) file_no,
 2  dbms_rowid.rowid_block_number(rowid) block_no  from t_xifenfei_new;

   FILE_NO   BLOCK_NO
---------- ----------
         9      19237

CDB_CDB$ROOT@SYS> alter system checkpoint;

系统已更改。

CDB_CDB$ROOT@SYS> alter system dump datafile 9 block 19237;

系统已更改。

dump block分析

buffer tsn: 3 rdba: 0x02404b25 (9/19237)
scn: 0xb8c.3c23c8b2 seq: 0x01 flg: 0x02 tail: 0xc8b20601
frmt: 0x02 chkval: 0x0000 type: 0x06=trans data
Hex dump of block: st=0, typ_found=1

tab 0, row 0, @0x1f83
tl: 21 fb: --H-FL-- lb: 0x1  cc: 2
col  0: [ 2]  c1 02
col  1: [14]  77 77 77 2e 6f 72 61 73 6f 73 2e 63 6f 6d
end_of_block_dump
End dump data blocks tsn: 3 file#: 9 minblk 19237 maxblk 19237

这里可以发现当设置db_block_checksum=false之时，插入数据,显示flg: 0×02，chkval: 0×0000，由此猜测无对block写入进行部分验证(tailchk依然验证)

使用bbed修改block

BBED> set filename 'E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF'
        FILENAME        E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF

BBED> set blocksize 19238
BBED-00108: illegal BLOCKSIZE (19238) specified


BBED> set blocksize 8192
        BLOCKSIZE       8192

BBED> set block 8192
        BLOCK#          8192

BBED> set blocksize 19238
BBED-00108: illegal BLOCKSIZE (19238) specified


BBED> set block 19238
        BLOCK#          19238

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        0x02404b25
   ub4 bas_kcbh                             @8        0x3c23c8b2
   ub2 wrp_kcbh                             @12       0x0b8c
   ub1 seq_kcbh                             @14       0x01
   ub1 flg_kcbh                             @15       0x02 (KCBHFDLC)
   ub2 chkval_kcbh                          @16       0x0000
   ub2 spare3_kcbh                          @18       0x0000
--这里看到flg_kcbh与chkval_kcbh和dump结果一致

BBED> sum
Check value for File 0, Block 19238:
current = 0x0000, required = 0x0000
--required为0，表示不验证

BBED> d /v offset 8174
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238   Offsets: 8174 to 8191  Dba:0x00000000
-------------------------------------------------------
 7777772e 6f726173 6f732e63 6f6d0106 l www.orasos.com..
 b2c8                                l 踩

 <16 bytes per line>

BBED> set mode edit
        MODE            Edit

BBED> m /x 78
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 8174 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 7877772e 6f726173 6f732e63 6f6d0106 b2c8

 <32 bytes per line>

BBED> d /v
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238   Offsets: 8174 to 8191  Dba:0x00000000
-------------------------------------------------------
 7877772e 6f726173 6f732e63 6f6d0106 l xww.orasos.com..
 b2c8                                l 踩

 <16 bytes per line>

--修改了block，但是sum依然提示required为0
BBED> sum
Check value for File 0, Block 19238:
current = 0x0000, required = 0x0000

BBED> sum apply
Check value for File 0, Block 19238:
current = 0x0000, required = 0x0000

dump block核对

buffer tsn: 3 rdba: 0x02404b25 (9/19237)
scn: 0xb8c.3c23c8b2 seq: 0x01 flg: 0x02 tail: 0xc8b20601
frmt: 0x02 chkval: 0x0000 type: 0x06=trans data
Hex dump of block: st=0, typ_found=1

tab 0, row 0, @0x1f83
tl: 21 fb: --H-FL-- lb: 0x1  cc: 2
col  0: [ 2]  c1 02
col  1: [14]  78 77 77 2e 6f 72 61 73 6f 73 2e 63 6f 6d
end_of_block_dump
End dump data blocks tsn: 3 file#: 9 minblk 19237 maxblk 19237

修改flg_kcbh测试

BBED> m /x 06 offset 15
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets:   15 to   30           Dba:0x00000000
------------------------------------------------------------------------
 06000000 00010000 00d86b01 00aec823

 <32 bytes per line>

BBED> sum
Check value for File 0, Block 19238:
current = 0x0000, required = 0x04b3
--修改flg_kcbh=x06后，sum中的required出现了非0值，表示已经启动了block完整性检测


BBED> m /x 79 offset 1876
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 1876 to 1891           Dba:0x00000000
------------------------------------------------------------------------
 79391b01 0000c24e 07000205 c406573f

 <32 bytes per line>

BBED> sum
Check value for File 0, Block 19238:
current = 0x0000, required = 0x049d

--修改了chkval_kcbh值
BBED> sum apply
Check value for File 0, Block 19238:
current = 0x049d, required = 0x049d

再次检查dump block

buffer tsn: 3 rdba: 0x02404b25 (9/19237)
scn: 0xb8c.3c23c8b2 seq: 0x01 flg: 0x06 tail: 0xc8b20601
frmt: 0x02 chkval: 0x049d type: 0x06=trans data
Hex dump of block: st=0, typ_found=1

tl: 21 fb: --H-FL-- lb: 0x1  cc: 2
col  0: [ 2]  c1 02
col  1: [14]  78 77 77 2e 6f 72 61 73 6f 73 2e 63 6f 6d
end_of_block_dump
End dump data blocks tsn: 3 file#: 9 minblk 19237 maxblk 19237

证明修改flg_kcbh后，block的sum验证起效

完整测试

--flg_kcbh=2,chkval_kcbh为04b3，修改block观察变化
BBED> sum
Check value for File 0, Block 19238:
current = 0x04b3, required = 0x04b3

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        0x02404b25
   ub4 bas_kcbh                             @8        0x3c23c8b2
   ub2 wrp_kcbh                             @12       0x0b8c
   ub1 seq_kcbh                             @14       0x01
   ub1 flg_kcbh                             @15       0x02 (KCBHFDLC)
   ub2 chkval_kcbh                          @16       0x04b3
   ub2 spare3_kcbh                          @18       0x0000

BBED> m /x 11 offset 7184
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 7184 to 7199           Dba:0x00000000
------------------------------------------------------------------------
 110000c2 39b50002 05c40721 07280000

 <32 bytes per line>

BBED> undo
BBED> modify /x 00 filename 'E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF' block 19238. offset 7184.
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 7184 to 7199           Dba:0x00000000
------------------------------------------------------------------------
 000000c2 39b50002 05c40721 07280000

 <32 bytes per line>


BBED> m /x 11 offset 8174
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 8174 to 8189           Dba:0x00000000
------------------------------------------------------------------------
 1177772e 6f726173 6f732e63 6f6d0106

 <32 bytes per line>

BBED> sum
Check value for File 0, Block 19238:
current = 0x04b3, required = 0x04b3
--证明当flg_kcbh=2修改block之后chkval_kcbh依然为04b3，证明flg_kcbh不含(KCBHFCKV),
--修改block不会导致chkval_kcbh改变，也就是说,该block为启用db_block_checksum 

--flg_kcbh=6的时候验证修改block导致的chkval_kcbh变化
BBED> m /x 06 offset 15
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets:   15 to   30           Dba:0x00000000
------------------------------------------------------------------------
 06b30400 00010000 00d86b01 00aec823

 <32 bytes per line>

--刚刚修改flg_kcbh=6,马上看到required非0
BBED> sum
Check value for File 0, Block 19238:
current = 0x04b3, required = 0x04da

BBED> sum apply
Check value for File 0, Block 19238:
current = 0x04da, required = 0x04da

--尝试修改block
BBED> m /x 22 offset 8174
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 8174 to 8189           Dba:0x00000000
------------------------------------------------------------------------
 2277772e 6f726173 6f732e63 6f6d0106

 <32 bytes per line>

--required发生改变
BBED> sum
Check value for File 0, Block 19238:
current = 0x04da, required = 0x04e9

BBED> sum apply
Check value for File 0, Block 19238:
current = 0x04e9, required = 0x04e9

--修改为以前值，验证required
BBED> m /x 11 offset 8174
 File: E:\APP\XIFENFEI\ORADATA\CDB\PDB\PDB_USERS01.DBF (0)
 Block: 19238            Offsets: 8174 to 8189           Dba:0x00000000
------------------------------------------------------------------------
 1177772e 6f726173 6f732e63 6f6d0106

 <32 bytes per line>

BBED> sum
Check value for File 0, Block 19238:
current = 0x04e9, required = 0x04da

BBED> sum apply
Check value for File 0, Block 19238:
current = 0x04da, required = 0x04da
--发现当block修改回来后，required值和以前一致(也就是说chkval_kcbh值还原)
--进步一说明chkval_kcbh取决于block内部值

通过相关测试db_block_checksum是在实例级别启动block checksum，但是具体到每个block是通过flg_kcbh来控制，而具体体现是在chkval_kcbh值上

发表在 Oracle | 标签为 bbed, db_block_checksum, flg_kcbh | 一条评论

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月归档：十月 2013

因RAC的undo_management参数不一致导致数据库mount报ORA-01105 ORA-01606

win平台rman备份和删除dg备库归档日志脚本

db_block_checksum实质是通过flg_kcbh来控制block checksum

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月归档：十月 2013

因RAC的undo_management参数不一致导致数据库mount报ORA-01105 ORA-01606

win平台rman备份和删除dg备库归档日志脚本

db_block_checksum实质是通过flg_kcbh来控制block checksum

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