[20170302]什么是fuzzy.txt

--如果你数据库正常打开的情况下,查询v$datafile_header视图:

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                             TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- -------------------------------- ------------------------------
    1        13276944334 2017-03-02 09:35:34                7       13276911100 ONLINE               862 YES /mnt/ramdisk/book/system01.dbf   SYSTEM
    2        13276944334 2017-03-02 09:35:34             1834       13276911100 ONLINE               851 YES /mnt/ramdisk/book/sysaux01.dbf   SYSAUX
    3        13276944334 2017-03-02 09:35:34           923328       13276911100 ONLINE               772 YES /mnt/ramdisk/book/undotbs01.dbf  UNDOTBS1
    4        13276944334 2017-03-02 09:35:34            16143       13276911100 ONLINE               857 YES /mnt/ramdisk/book/users01.dbf    USERS
    5        13276944334 2017-03-02 09:35:34           952916       13276911100 ONLINE               768 YES /mnt/ramdisk/book/example01.dbf  EXAMPLE
    6        13276944357 2017-03-02 09:35:48      13276257767       13276911100 ONLINE               242 YES /mnt/ramdisk/book/tea01.dbf      TEA
6 rows selected.
--//数据库正常运行一般都是Yes.视乎表示某种状态.
--这里的fuzzy表示什么?查询如下文章

Fuzzy File Warning When Recovering From Cold Backup [ID 103100.1]：

You are doing a restore from a cold backup using a backup controlfile.  On every file you receive the following message:
 
WARNING! Recovering data file <fno> from a fuzzy file. If not the current file it might be an online backup taken
without entering the begin backup command.
 
This message does not make sense as this is a cold backup.
 
This message is issued when you are performing recovery after restoring from a fuzzy backup due to the online fuzzy bit
is set in the file headers.Although this can be set when you do an online backup without issuing begin/end backup, it
can also be set when the system crashes. This is the case here; a shutdown abort had been performed prior
to the cold backup.

http://docs.oracle.com/cd/E11882_01/server.112/e40402/dynviews_1102.htm#REFRN30052
UZZY     VARCHAR2(3)     File is fuzzy (YES | NO)
--//不好理解!!自己先探索一下:

1.环境:
SYS@book> @ &r/ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

2.热备份模式:
SYS@book> ALTER TABLESPACE tea BEGIN BACKUP;
Tablespace altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                         TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ---------------------------- ---------------
    6        13276944908 2017-03-02 09:44:21      13276257767       13276911100 ONLINE               245 YES /mnt/ramdisk/book/tea01.dbf  TEA

--//依旧是fuzzy=yes.
--//视乎现在的版本与热备份无关.

SYS@book> ALTER TABLESPACE tea END BACKUP;
Tablespace altered.

3.设置表空间只读呢?
SYS@book> ALTER TABLESPACE tea read only;
Tablespace altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                        TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- --------------------------- ---------------
    6        13276945185 2017-03-02 09:48:30      13276257767       13276911100 ONLINE               247 NO  /mnt/ramdisk/book/tea01.dbf TEA
--//fuzzy=NO

SYS@book> ALTER TABLESPACE tea read write;
Tablespace altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                        TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- --------------------------- ---------------
    6        13276945259 2017-03-02 09:49:24      13276257767       13276911100 ONLINE               249 YES /mnt/ramdisk/book/tea01.dbf TEA

4.设置表空间offline:

SYS@book> ALTER TABLESPACE tea offline ;
Tablespace altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                         TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ---------------------------- ---------------
    6                  0                                    0                 0 OFFLINE                0
--//offline , fuzzy=null

SYS@book> ALTER TABLESPACE tea online ;
Tablespace altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                         TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ---------------------------- ---------------
    6        13276945505 2017-03-02 09:52:26      13276257767       13276911100 ONLINE               251 YES /mnt/ramdisk/book/tea01.dbf  TEA

5.设置数据文件6 offline:

SYS@book> alter database datafile 6 offline ;
Database altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                        TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- --------------------------- ---------------
    6        13276945505 2017-03-02 09:52:26      13276257767       13276911100 OFFLINE              251 YES /mnt/ramdisk/book/tea01.dbf TEA
--//依旧是fuzzy=yes.
SYS@book> recover datafile 6;
Media recovery complete.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                         TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ---------------------------- ---------------
    6        13276945602 2017-03-02 09:53:44      13276257767       13276911100 OFFLINE              252 NO  /mnt/ramdisk/book/tea01.dbf  TEA
--//恢复数据文件后,fuzzy=NO.

SYS@book> alter database datafile 6 online ;
Database altered.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=6;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                         TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ---------------------------- ---------------
    6        13276945744 2017-03-02 09:55:57      13276257767       13276911100 ONLINE               253 YES /mnt/ramdisk/book/tea01.dbf  TEA
--//数据文件online后,fuzzy=YES.

6.shutdown abort关闭数据库后:
SYS@book> shutdown abort ;
ORACLE instance shut down.

SYS@book> startup mount
ORACLE instance started.
Total System Global Area    634732544 bytes
Fixed Size                    2255792 bytes
Variable Size               197133392 bytes
Database Buffers            427819008 bytes
Redo Buffers                  7524352 bytes
Database mounted.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                             TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- -------------------------------- ----------------
    1        13276944334 2017-03-02 09:35:34                7       13276911100 ONLINE               862 YES /mnt/ramdisk/book/system01.dbf   SYSTEM
    2        13276944334 2017-03-02 09:35:34             1834       13276911100 ONLINE               851 YES /mnt/ramdisk/book/sysaux01.dbf   SYSAUX
    3        13276944334 2017-03-02 09:35:34           923328       13276911100 ONLINE               772 YES /mnt/ramdisk/book/undotbs01.dbf  UNDOTBS1
    4        13276944334 2017-03-02 09:35:34            16143       13276911100 ONLINE               857 YES /mnt/ramdisk/book/users01.dbf    USERS
    5        13276944334 2017-03-02 09:35:34           952916       13276911100 ONLINE               768 YES /mnt/ramdisk/book/example01.dbf  EXAMPLE
    6        13276945744 2017-03-02 09:55:57      13276257767       13276911100 ONLINE               253 YES /mnt/ramdisk/book/tea01.dbf      TEA
6 rows selected.
--//异常关闭数据库,到mount状态fuzzy=YES.

SYS@book> recover database;
Media recovery complete.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                             TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- -------------------------------- ---------------
    1        13276965838 2017-03-02 09:57:27                7       13276911100 ONLINE               863 NO  /mnt/ramdisk/book/system01.dbf   SYSTEM
    2        13276965838 2017-03-02 09:57:27             1834       13276911100 ONLINE               852 NO  /mnt/ramdisk/book/sysaux01.dbf   SYSAUX
    3        13276965838 2017-03-02 09:57:27           923328       13276911100 ONLINE               773 NO  /mnt/ramdisk/book/undotbs01.dbf  UNDOTBS1
    4        13276965838 2017-03-02 09:57:27            16143       13276911100 ONLINE               858 NO  /mnt/ramdisk/book/users01.dbf    USERS
    5        13276965838 2017-03-02 09:57:27           952916       13276911100 ONLINE               769 NO  /mnt/ramdisk/book/example01.dbf  EXAMPLE
    6        13276965838 2017-03-02 09:57:27      13276257767       13276911100 ONLINE               254 NO  /mnt/ramdisk/book/tea01.dbf      TEA
6 rows selected.
--//recover后,FUZZY=NO.从这里也可以看出如果正常关闭数据库,在status=online情况下fuzzy=NO.

7.shutdown immediate关闭数据库后:

SYS@book> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

SYS@book> startup mount;
ORACLE instance started.
Total System Global Area    634732544 bytes
Fixed Size                    2255792 bytes
Variable Size               197133392 bytes
Database Buffers            427819008 bytes
Redo Buffers                  7524352 bytes
Database mounted.
SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                             TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- -------------------------------- ---------------
    1        13276966464 2017-03-02 10:01:38                7       13276911100 ONLINE               867 NO  /mnt/ramdisk/book/system01.dbf   SYSTEM
    2        13276966464 2017-03-02 10:01:38             1834       13276911100 ONLINE               856 NO  /mnt/ramdisk/book/sysaux01.dbf   SYSAUX
    3        13276966464 2017-03-02 10:01:38           923328       13276911100 ONLINE               777 NO  /mnt/ramdisk/book/undotbs01.dbf  UNDOTBS1
    4        13276966464 2017-03-02 10:01:38            16143       13276911100 ONLINE               862 NO  /mnt/ramdisk/book/users01.dbf    USERS
    5        13276966464 2017-03-02 10:01:38           952916       13276911100 ONLINE               773 NO  /mnt/ramdisk/book/example01.dbf  EXAMPLE
    6        13276966464 2017-03-02 10:01:38      13276257767       13276911100 ONLINE               258 NO  /mnt/ramdisk/book/tea01.dbf      TEA
6 rows selected.
--//fuzzy=NO.

8.概括:
--//以上测试可以大概猜测fuzzy表示数据文件某种状态.
A.与是否热备无关
B.数据文件为read write ,status=online时，fuzzy=yes
C.数据文件为read only ，status=online时, fuzzy=no
D.数据文件为offline,
alter database datafile 6 offline;  则fuzzy为YES
alter tablespace USERS offline;     则fuzzy为NULL

--//可以这么理解FuzzY=NO表示一致的状态.这也就好理解昨天我恢复时:
--//链接http://blog.itpub.net/267265/viewspace-2134481/,最后为什么不能使用open resetlogs打开.因为我使用恢复时指定scn.
--//recover database using backup controlfile until change 13276911099;
--//oracle并不知道是否恢复结束.也就是有可能FUZZY还是YES.

9.继续测试:
SYS@book> shutdown abort ;
ORACLE instance shut down.

SYS@book> startup mount ;
ORACLE instance started.
Total System Global Area    634732544 bytes
Fixed Size                    2255792 bytes
Variable Size               197133392 bytes
Database Buffers            427819008 bytes
Redo Buffers                  7524352 bytes
Database mounted.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                             TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- -------------------------------- ---------------
    1        13276966467 2017-03-02 10:13:04                7       13276911100 ONLINE               868 YES /mnt/ramdisk/book/system01.dbf   SYSTEM
    2        13276966467 2017-03-02 10:13:04             1834       13276911100 ONLINE               857 YES /mnt/ramdisk/book/sysaux01.dbf   SYSAUX
    3        13276966467 2017-03-02 10:13:04           923328       13276911100 ONLINE               778 YES /mnt/ramdisk/book/undotbs01.dbf  UNDOTBS1
    4        13276966467 2017-03-02 10:13:04            16143       13276911100 ONLINE               863 YES /mnt/ramdisk/book/users01.dbf    USERS
    5        13276966467 2017-03-02 10:13:04           952916       13276911100 ONLINE               774 YES /mnt/ramdisk/book/example01.dbf  EXAMPLE
    6        13276966467 2017-03-02 10:13:04      13276257767       13276911100 ONLINE               259 YES /mnt/ramdisk/book/tea01.dbf      TEA
6 rows selected.
--//shut abort关闭数据库,fuzzy=YES.
SYS@book> @ &r/checkpoint
REDO:

检查点队列
  检查点队列                                           on disk rba                                        检查点队列
    脏块数量                                           时间戳              当前时间                       on disk rba scn    检查点心跳
       CPDRT low_rba              on_disk_rba          CPODT               SYSDATE              DIFF_DATE CPODS                   CPHBT  CURRENT_SCN     DIFF_SCN         INDX
------------ -------------------- -------------------- ------------------- ------------------- ---------- ---------------- ------------ ------------ ------------ ------------
          53 20.531.0             20.666.0             2017-03-02 10:13:10 2017-03-02 10:15:01     111.00 13276966781         937603690            0 -13276966781            0
--//理论on disk rba scn=13276966781.

SYS@book> recover database until change 13276966700;
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/mnt/ramdisk/book/system01.dbf'

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=1;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                           TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------ ---------------
    1        13276966700 2017-03-02 10:13:07                7       13276911100 ONLINE               868 YES /mnt/ramdisk/book/system01.dbf SYSTEM
--//fuzzy=YES.

SYS@book> recover database until change 13276966780;
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/mnt/ramdisk/book/system01.dbf'

SYS@book> recover database until change 13276966781;
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/mnt/ramdisk/book/system01.dbf'

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=1;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS  CHECKPOINT_COUNT FUZ NAME                           TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------ ---------------
    1        13276966781 2017-03-02 10:13:11                7       13276911100 ONLINE               868 YES /mnt/ramdisk/book/system01.dbf SYSTEM
--//fuzzy=YES.实际上我现在已经到最后的scn.

--//选择until cancel呢?
SYS@book> recover database until cancel;
ORA-00279: change 13276966781 generated at 03/02/2017 10:13:11 needed for thread 1
ORA-00289: suggestion : /u01/app/oracle/archivelog/book/1_20_937478950.dbf
ORA-00280: change 13276966781 for thread 1 is in sequence #20
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
/mnt/ramdisk/book/redo02.log
Log applied.
Media recovery complete.

SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE#  , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name  FROM v$datafile_header where file#=1;
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME     CREATION_CHANGE# RESETLOGS_CHANGE# STATUS     CHECKPOINT_COUNT FUZ NAME                           TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ---------- ---------------- --- ------------------------------ ---------------
    1        13276966782 2017-03-02 10:13:11                7       13276911100 ONLINE                  869 NO  /mnt/ramdisk/book/system01.dbf SYSTEM

--//fuzzy=NO,这时scn=13276966782.也就是将只有恢复到结束,oracle才会认为数据文件一致的.

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