oracle remap schema,【IMPDP】 实现不同用户之间的数据迁移——REMAP_SCHEMA参数

众所周知，IMP工具的FROMUSER和TOUSER参数可以实现将一个用户的的数据迁移到另外一个用户。同样的功能在IMPPDP工具中如何得以体现呢？答案就是：使用IMPPDP的REMAP_SCHEMA参数实现。简单演示一下，供参考。任务：将sec用户中的数据迁移到secooler用户。1.分别确认sec和secooler用户下的表和数据情况1)sec用户下有一张T表，含有24360行数据sys@ora10g> conn sec/secConnected.sec@ora10g> select * from tab;TNAME                          TABTYPE  CLUSTERID—————————— ——- ———-T                              TABLEsec@ora10g> select count(*) from t;COUNT(*)———-243602)确认secooler用户不包含表Tsecooler@ora10g> conn secooler/secoolerConnected.secooler@ora10g> select * from tab;no rows selected2.创建目录对象expdp_dirsys@ora10g> create or replace directory expdp_dir as ‘/expdp’;Directory created.3.将目录对象expdp_dir的读写权限授权给sec和secooler用户sys@ora10g> grant read,write on directory expdp_dir to sec;Grant succeeded.sys@ora10g> grant read,write on directory expdp_dir to secooler;Grant succeeded.4.生成sec的备份文件ora10g@secDB /expdp$ expdp sec/sec directory=expdp_dir dumpfile=`date +”%Y%m%d%H%M%S”`_sec.dmp logfile=`date +”%Y%m%d%H%M%S”`_sec.logExport: Release 10.2.0.3.0 – 64bit Production on Thursday, 01 April, 2010 10:29:17Copyright (c) 2003, 2005, Oracle.  All rights reserved.Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 – 64bit ProductionWith the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine optionsStarting “SEC”.”SYS_EXPORT_SCHEMA_01″:  sec/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec.logEstimate in progress using BLOCKS method…Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATATotal estimation using BLOCKS method: 3 MBProcessing object type SCHEMA_EXPORT/USERProcessing object type SCHEMA_EXPORT/SYSTEM_GRANTProcessing object type SCHEMA_EXPORT/ROLE_GRANTProcessing object type SCHEMA_EXPORT/DEFAULT_ROLEProcessing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMAProcessing object type SCHEMA_EXPORT/TABLE/TABLEProcessing object type SCHEMA_EXPORT/TABLE/INDEX/INDEXProcessing object type SCHEMA_EXPORT/TABLE/CONSTRAINT/CONSTRAINTProcessing object type SCHEMA_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICSProcessing object type SCHEMA_EXPORT/TABLE/COMMENT. . exported “SEC”.”T”                                   2.259 MB   24360 rowsMaster table “SEC”.”SYS_EXPORT_SCHEMA_01″ successfully loaded/unloaded******************************************************************************Dump file set for SEC.SYS_EXPORT_SCHEMA_01 is:/expdp/20100401102917_sec.dmpJob “SEC”.”SYS_EXPORT_SCHEMA_01″ successfully completed at 10:29:20生成的备份文件信息如下：ora10g@secDB /expdp$ ls -l *sec.dmp-rw-r—– 1 oracle oinstall 2.5M Apr  1 10:29 20100401102917_sec.dmp5.使用IMPDP的REMAP_SCHEMA参数实现secooler用户的数据导入ora10g@secDB /expdp$ impdp secooler/secooler directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log REMAP_SCHEMA=sec:secoolerImport: Release 10.2.0.3.0 – 64bit Production on Thursday, 01 April, 2010 10:32:10Copyright (c) 2003, 2005, Oracle.  All rights reserved.Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 – 64bit ProductionWith the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine optionsMaster table “SECOOLER”.”SYS_IMPORT_FULL_01″ successfully loaded/unloadedStarting “SECOOLER”.”SYS_IMPORT_FULL_01″:  secooler/******** directory=expdp_dir dumpfile=20100401102917_sec.dmp logfile=20100401102917_sec_impdp.log REMAP_SCHEMA=sec:secoolerProcessing object type SCHEMA_EXPORT/USERORA-31684: Object type USER:”SECOOLER” already existsProcessing object type SCHEMA_EXPORT/SYSTEM_GRANTProcessing object type SCHEMA_EXPORT/ROLE_GRANTProcessing object type SCHEMA_EXPORT/DEFAULT_ROLEProcessing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMAProcessing object type SCHEMA_EXPORT/TABLE/TABLEProcessing object type SCHEMA_EXPORT/TABLE/TABLE_DATA. . imported “SECOOLER”.”T”                              2.259 MB   24360 rowsJob “SECOOLER”.”SYS_IMPORT_FULL_01″ completed with 1 error(s) at 10:32:12OK，迁入任务完成。6.确认最后的迁移迁移成果连接到secooler用户确认T表及其中的数据是否已经完成导入。sec@ora10g> conn secooler/secoolerConnected.secooler@ora10g> select * from tab;TNAME                          TABTYPE  CLUSTERID—————————— ——- ———-T                              TABLEsecooler@ora10g> select count(*) from t;COUNT(*)———-24360OK，搞定。7.进一步参考资料最好的参考资料就是Oracle的官方文档，参考链接如下：http://download.oracle.com/docs/cd/B19306_01/server.102/b14215/dp_import.htm#sthref340便于参考，copy一份在此：

REMAP_SCHEMA

Default: none

Purpose

Loadsall objects from the source schema into a target schema.

Syntax and DescriptionREMAP_SCHEMA=source_schema:target_schema

MultipleREMAP_SCHEMAlines can be specified, but the source schema must be different for each one. However, different source schemas can map to the same target schema. The mapping may not be 100 percent complete, because there are certain schema references that Import is not capable of finding. For example, Import will not find schema references ××ded within the body of definitions of types, views, procedures, and packages.

If the schema you are remapping to does not already exist, the import operation creates it, provided the dump file set contains the necessaryCREATEUSERmetadata for the source schema and you are importing with enough privileges. For example, the following Export commands would create the dump file sets with the necessary metadata to create a schema, because the userSYSTEMhas the necessary privileges:> expdp SYSTEM/passwordSCHEMAS=hr

> expdp SYSTEM/passwordFULL=y

If your dump file set does not contain the metadata necessary to create a schema, or if you do not have privileges, then the target schema must be created before the import operation is performed. This is because the unprivileged dump files do not contain the necessary information for the import to create the schema automatically.

If the import operation does create the schema, then after the import is complete, you must assign it a valid password in order to connect to it. The SQL statement to do this, which requires privileges, is:SQL> ALTER USER [schema_name] IDENTIFIED BY [new_pswd]

Restrictions

Unprivileged users can perform. schema remaps only if their schema is the target schema of the remap. (Privileged users can perform. unrestricted schema remaps.)

For example,SCOTTcan remap hisBLAKE’s objects toSCOTT, butSCOTTcannot remapSCOTT’s objects toBLAKE.

Example

Suppose that you execute the following Export and Import commands to remap thehrschema into thescottschema:> expdp SYSTEM/passwordSCHEMAS=hr DIRECTORY=dpump_dir1 DUMPFILE=hr.dmp

> impdp SYSTEM/passwordDIRECTORY=dpump_dir1 DUMPFILE=hr.dmp

REMAP_SCHEMA=hr:scott

In this example, if userscottalready exists before the import, then the ImportREMAP_SCHEMAcommand will add objects from thehrschema into the existingscottschema. You can connect to thescottschema after the import by using the existing password (without resetting it).

If userscottdoes not exist before you execute the import operation, Import automatically creates it with an unusable password. This is possible because the dump file,hr.dmp, was created bySYSTEM,which has the privileges necessary to create a dump file that contains the metadata needed to create a schema. However, you cannot connect toscotton completion of the import, unless you reset the password forscotton the target database after the import completes.

8.小结在从EXP备份工具转到EXPDP工具的过程中，有很多的变动一定要注意，防止因误用导致效率低下。无论是从功能上还是效率上讲，EXPDP都是首选(需要在服务器端使用)。Good luck.secooler10.04.01