月归档：三月 2012

找回ASM中数据文件

发表于 2012 年 3 月 8 日由惜分飞

很多时候由于asm不能正常启动，导致数据丢失。下面提供两种方法找回asm中的数据文件
一.使用AMDU工具
AMDU是Oracle 11g里自带的一个免费的工具，用于分析ASM磁盘组的元数据以及从不能mount的磁盘组中往外抽取数据文件“NOTE:553639.1 Placeholder for AMDU binaries and using with ASM 10g”明确指出：AMDU也可用于10g，并提供了可用于10g的AMDU的各个操作系统的版本供大家下载。
1.设置LD_LIBRARY_PATH

rac1-> export LD_LIBRARY_PATH=/tmp/amdu

2.查看asm磁盘信息

rac1-> ./amdu -diskstring '/dev/raw/raw*'  
amdu_2012_03_05_03_17_19/
rac1-> cd amdu_2012_03_05_03_17_19/
rac1-> ls
report.txt
rac1-> more report.txt 
-*-amdu-*-

******************************* AMDU Settings ********************************
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1
System name:    Linux
Node name:      rac1
Release:        2.6.9-89.0.0.0.1.ELhugemem
Version:        #1 SMP Tue May 19 04:38:38 EDT 2009
Machine:        i686
amdu run:       05-MAR-12 03:17:19
Endianess:      1

--------------------------------- Operations ---------------------------------

------------------------------- Disk Selection -------------------------------
 -diskstring '/dev/raw/raw*'

------------------------------ Reading Control -------------------------------

------------------------------- Output Control -------------------------------

********************************* DISCOVERY **********************************

----------------------------- DISK REPORT N0001 ------------------------------
                Disk Path: /dev/raw/raw23
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0002 ------------------------------
                Disk Path: /dev/raw/raw11
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0003 ------------------------------
                Disk Path: /dev/raw/raw32
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0004 ------------------------------
                Disk Path: /dev/raw/raw31
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0005 ------------------------------
                Disk Path: /dev/raw/raw12
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0006 ------------------------------
                Disk Path: /dev/raw/raw2
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 1976 megabytes
               Group Name: DATA
                Disk Name: DATA_0001
       Failure Group Name: DATA_0001
              Disk Number: 1
            Header Status: 3
       Disk Creation Time: 2012/03/01 22:32:39.289000
          Last Mount Time: 2012/03/05 02:10:02.771000
    Compatibility Version: 0x0a100000
         Disk Sector Size: 512 bytes
         Disk size in AUs: 1976 AUs
         Group Redundancy: 1
      Metadata Block Size: 4096 bytes
                  AU Size: 1048576 bytes
                   Stride: 113792 AUs
      Group Creation Time: 2012/03/01 22:32:39.221000
  File 1 Block 1 location: AU 0

----------------------------- DISK REPORT N0007 ------------------------------
                Disk Path: /dev/raw/raw1
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 3137 megabytes
               Group Name: DATA
                Disk Name: DATA_0000
       Failure Group Name: DATA_0000
              Disk Number: 0
            Header Status: 3
       Disk Creation Time: 2012/03/01 22:32:39.289000
          Last Mount Time: 2012/03/05 02:10:02.771000
    Compatibility Version: 0x0a100000
         Disk Sector Size: 512 bytes
         Disk size in AUs: 3137 AUs
         Group Redundancy: 1
      Metadata Block Size: 4096 bytes
                  AU Size: 1048576 bytes
                   Stride: 113792 AUs
      Group Creation Time: 2012/03/01 22:32:39.221000
  File 1 Block 1 location: AU 2

******************************* END OF REPORT ********************************

从这里可以得到信息如下：
1)只有/dev/raw/raw1和raw2是有效的asm磁盘
2)磁盘组只有DATA

3.找出数据文件信息

rac1-> ../amdu -diskstring '/dev/raw/raw*'  -dump 'DATA'
amdu_2012_03_05_03_19_38/
rac1-> cd amdu_2012_03_05_03_19_38/
rac1-> ls
DATA_0001.img  DATA.map  report.txt
rac1-> strings DATA_0001.img |grep DATAFILE
DATAFILE
DATAFILE
DATAFILE
DEVDB/DATAFILE/SYSTEM.256.776817753
DEVDB/DATAFILE/SYSAUX.257.776817753
DEVDB/DATAFILE/UNDOTBS1.258.776817753
DEVDB/DATAFILE/USERS.259.776817753
DEVDB/DATAFILE/UNDOTBS2.267.776817909

从这里可以得出数据文件的file号(第一位数字)

4.恢复数据文件

rac1-> ../../amdu -diskstring '/dev/raw/raw*' -extract 'DATA.259'
amdu_2012_03_05_03_27_21/
rac1-> cd amdu_2012_03_05_03_27_21/
rac1-> ls -l
total 5148
-rw-r--r--  1 oracle oinstall 5251072 Mar  5 03:27 DATA_259.f
-rw-r--r--  1 oracle oinstall    6468 Mar  5 03:27 report.txt
rac1-> dbv file=DATA_259.f

DBVERIFY: Release 10.2.0.1.0 - Production on Mon Mar 5 03:28:00 2012

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

DBVERIFY - Verification starting : FILE = DATA_259.f


DBVERIFY - Verification complete

Total Pages Examined         : 640
Total Pages Processed (Data) : 15
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 2
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 26
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 597
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Highest block SCN            : 442362 (0.442362)

二.使用aulasm工具
1.配置ASM使用磁盘

[root@rac1 oracle]# more disk
/dev/sdb1
/dev/sdb2

2.使用aulasm

[root@rac1 oracle]# ./aulasm_linux32_trial.bin 
AUL : AnySQL UnLoader(MyDUL) for Oracle ASM, release 2.0.0

(C) Copyright Lou Fangxin 2011-2012 (AnySQL.net), all rights reserved.

ASM> help
  SET        -- set options (BLOCK_SIZE, AU_SIZE, F1B1_DISK, F1B1_AU)
  OPEN       -- open data file
  ADD        -- add disk with customized disk num (disk, path)
  LIST       -- list opened disks information (to)
  LSAU       -- list file of given AU (disk, au, count)
  FILE       -- list all file entries in ASM (file, [disk, au, block]).
  ALIAS      -- list all alias entries in ASM (file, [disk, au, block]).
  EXTENT     -- list or adjust variable extent (level, au, count).
  FMAP       -- list file extent (file, [disk, au, block], to)
  DUMP       -- dump file extent (file, [disk, au, block], offset, to)
  COPY       -- copy file to os  (file, [disk, au, block], to)
  QUIT/EXIT  -- exit the program.
ASM> open disk
2012-03-05 03:32:48
2012-03-05 03:32:48
ASM> list
2012-03-05 03:32:49
Total Disks = 2, ausize=1048576, blksize=4096

 disk     size block disk name        disk group   disk path               
===== ======== ===== ================ ============ ========================
    0     3137  4096 DATA_0000        DATA         /dev/sdb1
    1     1976  4096 DATA_0001        DATA         /dev/sdb2

f1b1disk = 0, f1b1au = 2, score=256, compat=0x0a100000
file=(1,0,2,1), disk=(2,0,2,2), alias=(6,0,2,6)
2012-03-05 03:32:49
ASM> alias
2012-03-05 03:33:15
    file          inc parent fstblk flag  refer alias                     
======== ============ ====== ====== ==== ====== ==========================
      -1           -1      0      0    4      1 DEVDB
      -1           -1      0      1    4      2 DATAFILE
      -1           -1      0      1    4      3 CONTROLFILE
      -1           -1      0      1    4      4 ONLINELOG
      -1           -1      0      1    4      5 TEMPFILE
      -1           -1      0      1    4      6 PARAMETERFILE
      -1           -1      0      1    4      7 ARCHIVELOG
     256    776817753      1      2   18     -1 SYSTEM
     257    776817753      1      2   18     -1 SYSAUX
     258    776817753      1      2   18     -1 UNDOTBS1
     259    776817753      1      2   18     -1 USERS
     267    776817909      1      2   18     -1 UNDOTBS2
     261    776817829      1      3   18     -1 Current
     260    776817829      1      3   18     -1 Current
     262    776817833      1      4   18     -1 group_1
     263    776817835      1      4   18     -1 group_1
     264    776817837      1      4   18     -1 group_2
     265    776817841      1      4   18     -1 group_2
     268    776818011      1      4   18     -1 group_3
     269    776818013      1      4   18     -1 group_3
     270    776818015      1      4   18     -1 group_4
     271    776818017      1      4   18     -1 group_4
     266    776817859      1      5   18     -1 TEMP
     272    776818021      1      6   18     -1 spfile
      -1           -1      1      7    4      8 2012_03_01
      -1           -1      1      7    4      9 2012_03_03
      -1           -1      1      7    4     10 2012_03_05
     273    776818747      7      8   18     -1 thread_1_seq_2
     274    776819571      7      8   18     -1 thread_1_seq_3
     275    776819721      7      8   18     -1 thread_2_seq_1
     276    776820331      7      8   18     -1 thread_1_seq_4
     277    776992321      7      9   18     -1 thread_1_seq_5
     278    776992321      7      9   18     -1 thread_2_seq_2
     279    777089437      7     10   18     -1 thread_1_seq_6
2012-03-05 03:33:15
ASM> fmap file 259    
2012-03-05 03:34:49
fid=259, disk=0, au=56, block=3
siz=5, ecnt=6, eeof=6, flags=17, type=12, alias=109,-1
     extid  disk       auid  cnt flg chk
========== ===== ========== ==== === ===
         1     0        428    1   0 135
         2     1        408    1   0 178
         3     0        429    1   0 134
         4     1        409    1   0 179
         5     0        430    1   0 133
         6     1        410    1   0 176
2012-03-05 03:34:49
ASM> copy file 259 to user_259
2012-03-05 03:35:01
2012-03-05 03:35:01
[root@rac1 oracle]# ll
total 6252
-rwxr-xr-x  1 root   root       84619 Mar  6  2012 aulasm_linux32_trial.bin
-rw-r--r--  1 root   root          20 Mar  5 02:52 disk
-rw-r--r--  1 root   root     6291456 Mar  5 03:35 user_259
[root@rac1 oracle]# su - oracle
rac1-> dbv file=user_259 

DBVERIFY: Release 10.2.0.1.0 - Production on Mon Mar 5 03:35:27 2012

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

DBVERIFY - Verification starting : FILE = user_259


DBVERIFY - Verification complete

Total Pages Examined         : 640
Total Pages Processed (Data) : 15
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 2
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 26
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 597
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Highest block SCN            : 442362 (0.442362)

通过dbv验证，两个数据文件(文件大小有出入，可能在对待未格式化数据块上，两者处理有出入)可以基本上确定一致，证明两种方法都可以从异常的ASM中获取数据文件

三.总结与比较
1.AMDU完全免费，aulasm超过16块硬盘需要收费
2.AMDU操作相对于aulasm麻烦一点，但是整体还是可以接受
3.获取到asm中的数据文件后恢复数据内容或者open库，那都是容易的事情
如果因为磁盘头损坏太多或者其他原因,以上方法都不能实现抽取asm磁盘组中数据文件,参考:asm disk header 彻底损坏恢复

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expdp中PARALLEL和DUMPFILE关系

发表于 2012 年 3 月 7 日由惜分飞

今天有朋友在说PARALLEL设置为n(大于1)，DUMPFILE为一个文件(不包含%U),会出现什么样的情况。下面通过实验来说明这个问题
1.当并发数比较大时(这里实验使用4),expdp会报ORA-39095错误

[oracle@node1 tmp]$ expdp chf/xifenfei DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=4

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:48:52 2012

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, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
Starting "CHF"."SYS_EXPORT_TABLE_01":  chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=4 
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 5.362 GB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
ORA-39095: Dump file space has been exhausted: Unable to allocate 8192 bytes

2.并发数较少时(实验为2),通过attach观察
2.1)执行expdp导出

[oracle@node1 tmp]$ expdp chf/xifenfei DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:49:15 2012

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, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
Starting "CHF"."SYS_EXPORT_TABLE_02":  chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2 
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 5.362 GB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
. . exported "CHF"."T1"                                  4.647 GB 51080958 rows
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
Master table "CHF"."SYS_EXPORT_TABLE_02" successfully loaded/unloaded
******************************************************************************
Dump file set for CHF.SYS_EXPORT_TABLE_02 is:
  /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
Job "CHF"."SYS_EXPORT_TABLE_02" successfully completed at 20:52:23

2.2)在导出过程中，使用attach观察expdp工作情况

[oracle@node1 trace]$ expdp chf/xifenfei attach=SYS_EXPORT_TABLE_02

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:49:38 2012

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, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options

Job: SYS_EXPORT_TABLE_02
  Owner: CHF                            
  Operation: EXPORT                         
  Creator Privs: TRUE                           
  GUID: BAA7964815021C96E0438C09A8C04319
  Start Time: Wednesday, 07 March, 2012 20:49:16
  Mode: TABLE                          
  Instance: chf
  Max Parallelism: 2
  EXPORT Job Parameters:
  Parameter Name      Parameter Value:
     CLIENT_COMMAND        chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2 
  State: EXECUTING                      
  Bytes Processed: 0
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,096
  
Worker 1 Status:
  Process Name: DW00
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE
  Completed Objects: 1
  Total Objects: 1
  Worker Parallelism: 1
  
Worker 2 Status:
  Process Name: DW02
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE_DATA
  Completed Objects: 1
  Total Objects: 1
  Completed Rows: 16,104,279
  Worker Parallelism: 1

Export> status

Job: SYS_EXPORT_TABLE_02
  Operation: EXPORT                         
  Mode: TABLE                          
  State: EXECUTING                      
  Bytes Processed: 0
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,096
  
Worker 1 Status:
  Process Name: DW00
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE
  Completed Objects: 1
  Total Objects: 1
  Worker Parallelism: 1
  
Worker 2 Status:
  Process Name: DW02
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE_DATA
  Completed Objects: 1
  Total Objects: 1
  Completed Rows: 35,425,534
  Worker Parallelism: 1

Export> status

Job: SYS_EXPORT_TABLE_02
  Operation: EXPORT                         
  Mode: TABLE                          
  State: COMPLETING                     
  Bytes Processed: 4,989,989,105
  Percent Done: 100
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,990,009,344
  
Worker 1 Status:
  Process Name: DW00
  State: WORK WAITING                   
  
Worker 2 Status:
  Process Name: DW02
  State: WORK WAITING

3.最终结论
3.1)如果并发设置过大，在导出过程中直接报错
3.2)如果导出文件数量少于并发数时，多于并发将不会工作。

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LNNVL函数使用

发表于 2012 年 3 月 6 日由惜分飞

LNNVL官方解释
LNNVL provides a concise way to evaluate a condition when one or both operands of the condition may be null. The function can be used only in the WHERE clause of a query. It takes as an argument a condition and returns TRUE if the condition is FALSE or UNKNOWN and FALSE if the condition is TRUE. LNNVL can be used anywhere a scalar expression can appear, even in contexts where the IS [NOT] NULL, AND, or OR conditions are not valid but would otherwise be required to account for potential nulls. Oracle Database sometimes uses the LNNVL function internally in this way to rewrite NOT IN conditions as NOT EXISTS conditions. In such cases, output from EXPLAIN PLAN shows this operation in the plan table output. The condition can evaluate any scalar values but cannot be a compound condition containing AND, OR, or BETWEEN.

LNNVL官方解释翻译
lnnvl用于某个语句的where子句中的条件，如果条件为true就返回false；如果条件为UNKNOWN或者false就返回true。该函数不能用于复合条件如AND, OR, or BETWEEN中。

模拟测试环境

SQL> create table xifenfei(name varchar2(20),year number);

Table created.

SQL> insert into xifenfei values('xifenfei2001',2001);

1 row created.

SQL> insert into xifenfei values('xifenfei2002',2002);

1 row created.

SQL> insert into xifenfei values('xifenfei2003',2003);

1 row created.

SQL> insert into xifenfei values('xifenfei2004',2004);

1 row created.

SQL> insert into xifenfei values('xifenfei2005',2005);

1 row created.

SQL> insert into xifenfei values('xifenfei2006',2006);

1 row created.

SQL> insert into xifenfei values('xifenfei2007',2007);

1 row created.

SQL> insert into xifenfei values('xifenfei2008',null);

1 row created.

SQL> insert into xifenfei values('xifenfei2009',2009);

1 row created.

SQL> insert into xifenfei values('xifenfei2010',2010);

1 row created.

SQL> insert into xifenfei values('xifenfei2011',2011);

1 row created.

SQL> commit;

Commit complete.

SQL> select * from xifenfei;

NAME                       YEAR
-------------------- ----------
xifenfei2001               2001
xifenfei2002               2002
xifenfei2003               2003
xifenfei2004               2004
xifenfei2005               2005
xifenfei2006               2006
xifenfei2007               2007
xifenfei2008
xifenfei2009               2009
xifenfei2010               2010
xifenfei2011               2011

11 rows selected.

几种情况测试说明

--年份小于2009(lnnvl表示年份大于或者2009包含null)
SQL> select * from xifenfei where lnnvl(year<2009);

NAME                       YEAR
-------------------- ----------
xifenfei2008
xifenfei2009               2009
xifenfei2010               2010
xifenfei2011               2011

--year不为null(lnnvl表示年份为null)
SQL> select * from xifenfei where lnnvl(year is not null);

NAME                       YEAR
-------------------- ----------
xifenfei2008

--年份为null(lnnvl表示年份不为null)
SQL> select * from xifenfei where lnnvl(year is  null);

NAME                       YEAR
-------------------- ----------
xifenfei2001               2001
xifenfei2002               2002
xifenfei2003               2003
xifenfei2004               2004
xifenfei2005               2005
xifenfei2006               2006
xifenfei2007               2007
xifenfei2009               2009
xifenfei2010               2010
xifenfei2011               2011

10 rows selected.

--年份为12345(lnnvl表示年份不为12345)
SQL> select * from xifenfei where lnnvl(year =12345);

NAME                       YEAR
-------------------- ----------
xifenfei2001               2001
xifenfei2002               2002
xifenfei2003               2003
xifenfei2004               2004
xifenfei2005               2005
xifenfei2006               2006
xifenfei2007               2007
xifenfei2008
xifenfei2009               2009
xifenfei2010               2010
xifenfei2011               2011

11 rows selected.

--年份不为12345(lnnvl表示年份为12345或者null)
SQL> select * from xifenfei where lnnvl(year !=12345);

NAME                       YEAR
-------------------- ----------
xifenfei2008

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月归档：三月 2012

找回ASM中数据文件

expdp中PARALLEL和DUMPFILE关系

LNNVL函数使用

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月归档：三月 2012

找回ASM中数据文件

expdp中PARALLEL和DUMPFILE关系

LNNVL函数使用

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