在有些时候,exp的dmp文件因为某种原因损坏(比如磁盘异常,exp过程损坏等),导致imp导入无法继续，下面的处理方法(直接读取dmp文件)来对dmp文件进行抢救性恢复,最大程度减少数据丢失损失
创建exp dmp文件并使用dd破坏

SQL> create table t_xifenfei as select * from dba_objects;
Table created.
SQL> select count(*) from t_xifenfei;
  COUNT(*)
----------
     90915
[oracle@localhost ~]$ exp chf/xifenfei@pdb1 file=/tmp/t_xifenfei.dmp tables=t_xifenfei
Export: Release 12.1.0.2.0  on Sun Apr 27 21:39:26 2014
Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
Export done in US7ASCII character set and AL16UTF16 NCHAR character set
server uses WE8MSWIN1252 character set (possible charset conversion)
About to export specified tables via Conventional Path ...
. . exporting table                     T_XIFENFEI      90915 rows exported
EXP-00091: Exporting questionable statistics.
Export terminated successfully with warnings.
[oracle@localhost ~]$ od -x /tmp/t_xifenfei.dmp |head -10
0000000 0003 4501 5058 524f 3a54 3156 2e32 3130
0000020 302e 0a30 4344 4648 520a 4154 4c42 5345
0000040 380a 3931 0a32 0a30 3237 300a 000a 0001
0000060 07b2 00d0 0001 0000 0000 0000 0000 0013
0000100 2020 2020 2020 2020 2020 2020 2020 2020
*
0000140 2020 2020 2020 2020 7553 206e 7041 2072
0000160 3732 3220 3a31 3933 323a 2036 3032 3431
0000200 742f 706d 742f 785f 6669 6e65 6566 2e69
0000220 6d64 0070 0000 0000 0000 0000 0000 0000
--strings命令看dmp文件
[oracle@localhost ~]$ strings /tmp/t_xifenfei.dmp |head -50
EXPORT:V12.01.00
DCHF
RTABLES
8192
                                         Tue Apr 29 0:39:49 2014/tmp/t_xifenfei.dmp
#G#G
#G#G
+08:00
BYTE
UNUSED
INTERPRETED
DISABLE:ALL
METRICST
TABLE "T_XIFENFEI"
CREATE TABLE "T_XIFENFEI" ("OWNER" VARCHAR2(128), "OBJECT_NAME" VARCHAR2(128), "SUBOBJECT_NAME" VARCHAR2(128), "OBJECT_ID" NUMBER, "DATA_OBJECT_ID" NUMBER, "OBJECT_TYPE" VARCHAR2(23), "CREATED" DATE, "LAST_DDL_TIME" DATE, "TIMESTAMP" VARCHAR2(19), "STATUS" VARCHAR2(7), "TEMPORARY" VARCHAR2(1), "GENERATED" VARCHAR2(1), "SECONDARY" VARCHAR2(1), "NAMESPACE" NUMBER, "EDITION_NAME" VARCHAR2(128), "SHARING" VARCHAR2(13), "EDITIONABLE" VARCHAR2(1), "ORACLE_MAINTAINED" VARCHAR2(1))  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 STORAGE(INITIAL 13631488 NEXT 1048576 MINEXTENTS 1 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "USERS" LOGGING NOCOMPRESS
INSERT INTO "T_XIFENFEI" ("OWNER", "OBJECT_NAME", "SUBOBJECT_NAME", "OBJECT_ID", "DATA_OBJECT_ID", "OBJECT_TYPE", "CREATED", "LAST_DDL_TIME", "TIMESTAMP", "STATUS", "TEMPORARY", "GENERATED", "SECONDARY", "NAMESPACE", "EDITION_NAME", "SHARING", "EDITIONABLE", "ORACLE_MAINTAINED") VALUES (:1, :2, :3, :4, :5, :6, :7, :8, :9, :10, :11, :12, :13, :14, :15, :16, :17, :18)
PUBLIC
V$DATAGUARD_CONFIG
SYNONYM
2014-04-22:17:51:05
VALID
METADATA LINK
V_$DATAGUARD_STATS
VIEW
2014-04-22:17:51:05
--破坏exp dmp文件
[oracle@localhost ~]$ dd if=/dev/zero of=/tmp/t_xifenfei.dmp bs=1024 count=1 conv=notrunc
1+0 records in
1+0 records out
1024 bytes (1.0 kB) copied, 6.0291e-05 seconds, 17.0 MB/s
[oracle@localhost ~]$ od -x /tmp/t_xifenfei.dmp |head -10
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0020000 0064 0000 6000 2401 050f 0c0b 0c03 050c
0020020 0504 060d 0709 0508 0505 0505 050f 0505
0020040 0505 050a 0505 0505 0504 0706 0808 4723
0020060 4723 1108 0823 4111 47b0 8300 b200 d007
0020100 0003 0000 0000 0000 0000 0000 0000 0000
0020120 0000 0000 0000 0000 0000 0000 0000 0000
0020140 0000 0000 0000 0064 0000 6000 2401 050f
0020160 0c0b 0c03 050c 0504 060d 0709 0508 0505
--损坏后的dmp文件使用strings命令看
[oracle@localhost ~]$ strings /tmp/t_xifenfei.dmp |head -50
#G#G
#G#G
+08:00
BYTE
UNUSED
INTERPRETED
DISABLE:ALL
METRICST
TABLE "T_XIFENFEI"
CREATE TABLE "T_XIFENFEI" ("OWNER" VARCHAR2(128), "OBJECT_NAME" VARCHAR2(128), "SUBOBJECT_NAME" VARCHAR2(128), "OBJECT_ID" NUMBER, "DATA_OBJECT_ID" NUMBER, "OBJECT_TYPE" VARCHAR2(23), "CREATED" DATE, "LAST_DDL_TIME" DATE, "TIMESTAMP" VARCHAR2(19), "STATUS" VARCHAR2(7), "TEMPORARY" VARCHAR2(1), "GENERATED" VARCHAR2(1), "SECONDARY" VARCHAR2(1), "NAMESPACE" NUMBER, "EDITION_NAME" VARCHAR2(128), "SHARING" VARCHAR2(13), "EDITIONABLE" VARCHAR2(1), "ORACLE_MAINTAINED" VARCHAR2(1))  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 STORAGE(INITIAL 13631488 NEXT 1048576 MINEXTENTS 1 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "USERS" LOGGING NOCOMPRESS
INSERT INTO "T_XIFENFEI" ("OWNER", "OBJECT_NAME", "SUBOBJECT_NAME", "OBJECT_ID", "DATA_OBJECT_ID", "OBJECT_TYPE", "CREATED", "LAST_DDL_TIME", "TIMESTAMP", "STATUS", "TEMPORARY", "GENERATED", "SECONDARY", "NAMESPACE", "EDITION_NAME", "SHARING", "EDITIONABLE", "ORACLE_MAINTAINED") VALUES (:1, :2, :3, :4, :5, :6, :7, :8, :9, :10, :11, :12, :13, :14, :15, :16, :17, :18)
PUBLIC
V$DATAGUARD_CONFIG
SYNONYM
2014-04-22:17:51:05
VALID
METADATA LINK
V_$DATAGUARD_STATS
--imp 导入dmp文件失败
[oracle@localhost ~]$ imp chf/xifenfei@pdb1 file=/tmp/t_xifenfei.dmp full=y
Import: Release 12.1.0.2.0 -      on Sun Apr 27 22:02:40 2014
Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
IMP-00037: Character set marker unknown
IMP-00000: Import terminated unsuccessfully

这里通过分析可以知道，exp dmp文件虽然损坏了一点,但是通过strings命令看，相关记录依然存在,因此可以通过工具去读exp dmp文件,然后分析得出相关数据

恢复损坏exp dmp文件数据

CPFL> SEARCH TABLE T_XIFENFEI FROM EXPFILE  /tmp/t_xifenfei.dmp
8461: TABLE "T_XIFENFEI"
8480: CREATE TABLE "T_XIFENFEI" ("OWNER" VARCHAR2(128), "OBJECT_NAME" VARCHAR2(128), "SUBOBJECT_NAME" VARCHAR2(128), "OBJECT_ID" NUMBER, "DATA_OBJECT_ID" NUMBER, "OBJECT_TYPE" VARCHAR2(23), "CREATED" DATE, "LAST_DDL_TIME" DATE, "TIMESTAMP" VARCHAR2(19), "STATUS" VARCHAR2(7), "TEMPORARY" VARCHAR2(1), "GENERATED" VARCHAR2(1), "SECONDARY" VARCHAR2(1), "NAMESPACE" NUMBER, "EDITION_NAME" VARCHAR2(128), "SHARING" VARCHAR2(13), "EDITIONABLE" VARCHAR2(1), "ORACLE_MAINTAINED" VARCHAR2(1))  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 STORAGE(INITIAL 8388608 NEXT 1048576 MINEXTENTS 1 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "USERS" LOGGING NOCOMPRESS
9145: INSERT INTO "T_XIFENFEI" ("OWNER", "OBJECT_NAME", "SUBOBJECT_NAME", "OBJECT_ID", "DATA_OBJECT_ID", "OBJECT_TYPE", "CREATED", "LAST_DDL_TIME", "TIMESTAMP", "STATUS", "TEMPORARY", "GENERATED", "SECONDARY", "NAMESPACE", "EDITION_NAME", "SHARING", "EDITIONABLE", "ORACLE_MAINTAINED") VALUES (:1, :2, :3, :4, :5, :6, :7, :8, :9, :10, :11, :12, :13, :14, :15, :16, :17, :18)
Conventional export
9644: start of table data
12331252: TABLE "T_XIFENFEI"
12331349: ENDTABLE
CPFL> UNLOAD  TABLE "T_XIFENFEI" ("OWNER" VARCHAR2(128), "OBJECT_NAME" VARCHAR2(128), "SUBOBJECT_NAME" VARCHAR2(128), "OBJECT_ID" NUMBER, "DATA_OBJECT_ID" NUMBER, "OBJECT_TYPE" VARCHAR2(23), "CREATED" DATE, "LAST_DDL_TIME" DATE, "TIMESTAMP" VARCHAR2(19), "STATUS" VARCHAR2(7), "TEMPORARY" VARCHAR2(1), "GENERATED" VARCHAR2(1), "SECONDARY" VARCHAR2(1), "NAMESPACE" NUMBER, "EDITION_NAME" VARCHAR2(128), "SHARING" VARCHAR2(13), "EDITIONABLE" VARCHAR2(1), "ORACLE_MAINTAINED" VARCHAR2(1))  expfile  /tmp/t_xifenfei.dmp from 8480 until 12331349
--因为exp dmp文件损坏记录
CPFL: Error: column 1 length 21059 exceeds max bind size 128
0000000000 45415445 20544142 4c452022 545f5849 EATE  TAB LE " T_XI
0000000016 46454e46 45492220 28224f57 4e455222 FENF EI"  ("OW NER"
0000000032 20564152 43484152                    VAR CHAR
8480: column 1 type VARCHAR2 size 21059 failed
8480: row 1 failed
row conversion failure, retrying from offset 8481
CPFL: Error: Zero (illegal) length column number 2
…………
CPFL: Error: Zero (illegal) length column number 1
9644: succesful conversion      1164 bytes skipped due to conversion problems
131877: row 1000 ok
253310: row 2000 ok
…………
12200617: row 90000 ok
Unloaded 90915 rows, end of table marker at 12322835
[oracle@localhost CPFL]$ ls -ltr T_XIFENFEI.*
-rw-r--r-- 1 oracle oinstall 17230747 Apr 27 22:12 T_XIFENFEI.dat
-rw-r--r-- 1 oracle oinstall     1489 Apr 27 22:17 T_XIFENFEI.ctl

导入数据并对比

SQL> create table t_xifenfei_exp as select * from t_xifenfei where 1=0;
Table created.
[oracle@localhost CPFL]$ more T_XIFENFEI.ctl
load data
CHARACTERSET UTF8
infile 'T_XIFENFEI.dat'
insert
into table "T_XIFENFEI_EXP"  ---修改为T_XIFENFEI_EXP表
fields terminated by whitespace
(
  "OWNER"                            CHAR(128) enclosed by X'7C'
 ,"OBJECT_NAME"                      CHAR(128) enclosed by X'7C'
 ,"SUBOBJECT_NAME"                   CHAR(29) enclosed by X'7C'
 ,"OBJECT_ID"                        CHAR(5) enclosed by X'7C'
 ,"DATA_OBJECT_ID"                   CHAR(5) enclosed by X'7C'
 ,"OBJECT_TYPE"                      CHAR(20) enclosed by X'7C'
 ,"CREATED"                          DATE "DD-MON-YYYY AD HH24:MI:SS" enclosed by X'7C'
 ,"LAST_DDL_TIME"                    DATE "DD-MON-YYYY AD HH24:MI:SS" enclosed by X'7C'
 ,"TIMESTAMP"                        CHAR(19) enclosed by X'7C'
 ,"STATUS"                           CHAR(5) enclosed by X'7C'
 ,"TEMPORARY"                        CHAR(1) enclosed by X'7C'
 ,"GENERATED"                        CHAR(1) enclosed by X'7C'
 ,"SECONDARY"                        CHAR(1) enclosed by X'7C'
 ,"NAMESPACE"                        CHAR(2) enclosed by X'7C'
 ,"EDITION_NAME"                     CHAR(1) enclosed by X'7C'
 ,"SHARING"                          CHAR(13) enclosed by X'7C'
 ,"EDITIONABLE"                      CHAR(1) enclosed by X'7C'
 ,"ORACLE_MAINTAINED"                CHAR(1) enclosed by X'7C'
 ,"UNEXP_STATUS"                     FILLER CHAR(3) enclosed by X'7C'
)
[oracle@localhost CPFL]$ sqlldr chf/xifenfei@pdb1 control=T_XIFENFEI.ctl
SQL*Loader: Release 12.1.0.1.0       on Sun Apr 27 22:17:54 2014
Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.
Path used:      Conventional
Commit point reached - logical record count 64
Commit point reached - logical record count 128
Commit point reached - logical record count 192
…………
Commit point reached - logical record count 90887
Commit point reached - logical record count 90915
Table "T_XIFENFEI_EXP":
  90915 Rows successfully loaded.
Check the log file:
  T_XIFENFEI.log
for more information about the load.
[oracle@localhost CPFL]$ sqlplus chf/xifenfei@pdb1
SQL*Plus: Release 12.1.0.2.0 Beta on Sun Apr 27 22:18:08 2014
Copyright (c) 1982, 2014, Oracle.  All rights reserved.
Last Successful login time: Sun Apr 27 2014 22:17:54 +08:00
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> select count(*) from t_xifenfei_exp;
  COUNT(*)
----------
     90915
SQL> select * from t_xifenfei
  2  minus
  3  select * from t_xifenfei_exp;
no rows selected

通过这里可以看出来，在exp dmp文件有部分损坏的情况下,还是可以通过直接读取dmp文件的方式恢复全部或者部分exp dmp文件中内容(具体恢复量取决于dmp文件损坏程度)

如果你在使用这些思路进行恢复遇到突发情况不能自行解决,请联系我们(ORACLE数据库恢复技术支持),将为您提供专业数据库技术支持：
Phone:17813235971    Q Q:107644445    E-Mail:dba@xifenfei.com