实验环境:
服务器A:172.21.1.30 服务器B:172.21.1.40 两台服务器上分别运行两套oracle数据库,本实验以scott用户为例进行测试。
实验目的:
通过DB_LINK的复制功能,利用expdp,impdp进行数据的远程备份及恢复。 进行测试前,将服务器B上scott用户的dept,emp进行删除,本测试只是使用 impdp将服务器A数据库下scott用户的dept,emp表导入到服务器B数据库 scott用户下。
操作步骤:
1.在服务器A,B上分别以sys身份登录数据库,并创建directory,db_link,命令如下: session A: > create directory dp01 as '/bk/dp01'; Directory created. session A: >create public database link ln_db40 connect to scott identified by tiger using 'ip40'; Database link created. session A: >grant connect,resource,exp_full_database,imp_full_database to scott identified by tiger; Grant succeeded. session B: > create directory dp02 as '/bk/dp02'; session B: >create public database link ln_db30 connect to scott identified by tiger using 'ip30'; session B: >grant connect,resource,exp_full_database,imp_full_database to scott identified by tiger; 2.在确认以上步骤中的db_link没问题后,做以下操作: a. 服务器A:(将本地数据库中scott用户下的dept,emp两张表导出备份文件为exp01.dmp)
[oracle@session A: dp01]$ expdp scott/tiger directory=dp01 dumpfile=exp01.dmp network_link=ln_db30 tables=emp,dept Export: Release 10.2.0.1.0 - Production on Wednesday, 03 August, 2011 14:39:05 Copyright (c) 2003, 2005, Oracle. All rights reserved. Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production With the Partitioning, OLAP and Data Mining options Starting "SCOTT"."SYS_EXPORT_SCHEMA_01": scott/********@ip30 directory=dp01 dumpfile=exp01.dmp network_link=ln_db30 tables=emp,dept Estimate in progress using BLOCKS method... Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA Total estimation using BLOCKS method: 320 KB Processing object type SCHEMA_EXPORT/USER Processing object type SCHEMA_EXPORT/SYSTEM_GRANT Processing object type SCHEMA_EXPORT/ROLE_GRANT Processing object type SCHEMA_EXPORT/DEFAULT_ROLE Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA Processing object type SCHEMA_EXPORT/TABLE/TABLE Processing object type SCHEMA_EXPORT/TABLE/INDEX/INDEX Processing object type SCHEMA_EXPORT/TABLE/CONSTRAINT/CONSTRAINT Processing object type SCHEMA_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS Processing object type SCHEMA_EXPORT/TABLE/COMMENT Processing object type SCHEMA_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT . . exported "SCOTT"."SYS_EXPORT_SCHEMA_01" 172.8 KB 1073 rows . . exported "SCOTT"."DEPT" 5.656 KB 4 rows . . exported "SCOTT"."EMP" 7.820 KB 14 rows Master table "SCOTT"."SYS_EXPORT_SCHEMA_01" successfully loaded/unloaded ****************************************************************************** Dump file set for SCOTT.SYS_EXPORT_SCHEMA_01 is: /bk/dp01/exp01.dmp Job "SCOTT"."SYS_EXPORT_SCHEMA_01" successfully completed at 14:39:37 [oracle@session A: dp01]$ ls exp01.dmp export.log import.log b. 将备份文件exp01.dmp从服务器A拷贝到服务器B: [oracle@session A: dp01]$ scp –r exp01.dmp 172.21.1.40:/bk/dp02/ c.在服务器A上,执行以下命令,将dept,emp表导入到服务器B的scott用户下: [oracle@session A: dp01]$ impdp scott/tiger@ip40 directory=dp02 dumpfile=exp01.dmp tables=emp,dept Import: Release 10.2.0.1.0 - Production on Wednesday, 03 August, 2011 14:34:57 Master table "SCOTT"."SYS_IMPORT_TABLE_01" successfully loaded/unloaded Starting "SCOTT"."SYS_IMPORT_TABLE_01": scott/********@ip40 directory=dp02 dumpfile=exp01.dmp tables=emp,dept Processing object type TABLE_EXPORT/TABLE/TABLE Processing object type TABLE_EXPORT/TABLE/TABLE_DATA . . imported "SCOTT"."DEPT" 5.656 KB 4 rows . . imported "SCOTT"."EMP" 7.820 KB 14 rows Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/CONSTRAINT Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT Job "SCOTT"."SYS_IMPORT_TABLE_01" successfully completed at 14:34:55
3.使用sys用户登录服务器A的数据库,进行测试,查看B的scott用户下的dept,emp表是否存在: $ sqlplus / as sysdba session A: > conn scott/tiger Connected. session A: > select * from tab; TNAME TABTYPE CLUSTERID ------------------------------ ------- ---------- DEPT TABLE EMP TABLE session A: > select * from tab@ln_db40;
由以上实验不难看出,表dept,emp已成功导入B的scott用户。
EXPDP 可以导出所有数据库的数据,只要它能连接到这个数据库,或者它登录的数据库
上能读取到被导出的库的数据,因为此时可以通过数据库链来读取被导出的库的数据。
如下测试:
可以分为三个服务器:A,B,C,以下命令在A在执行:
说明:
expdp 在服务器A上;
network_link=ln_db30 是服务器B的数据库中scott用户的数据库链,其指向服务器C的用户scott,
SCOTT10用户中只有两个表dept,emp.
从上面的操作可以看出:expdp 可以是客户端的程序,但它导出的数据(DMP)必须存放在它登录
的数据库的目录下(本例中,存放在机器B的数据库directory=dp02下),而被导出的数据是通过
数据库链(network_link)到机器C的数据库里读取的。
另外注意:在这过程中,A数据库用户scott和C数据库用户scott(或者数据库链中的用户)都必须被
授予EXP_FULL_DATABASE 权限。
nelwork_link意思是从本地数据库导入datafile直接到remote database,中间省略了exp的操作,
nelwork_link=source_database_link,确认nelwork_link参数是一个存在的目标数据库名称,同时
存在database link.
补充一下两个限制条件:
<b>nelwork_link parameter Restrictions</b>
Network imports do not support the use of evolved types.
<b>a:</b> When the NETWORK_LINK parameter is used in conjunction with the TABLES parameter,
only whole tables can be imported (not partitions of tables).
所以,当使用impdp导入时多张表时,如果添加network_link参数,就会报错如下:
UDI-00011: parameter dumpfile is incompatible with parameter network_link
<b>b:</b> If the USERID that is executing the import job has the IMP_FULL_DATABASE role on the
target database, then that user must also have the EXP_FULL_DATABASE role on the source
database.The only types of database links supported by Data Pump Import are: public,
fixed-user, and connected-user. Current-user database links are not supported.
本文转自vcdog 51CTO博客,原文链接:http://blog.51cto.com/255361/837646,如需转载请自行联系原作者