Data Pump impdp expdp NETWORK_LINK option

First what is the network_Link Option :

you can import the schema from source database to target database. One advantage of this option you don’t need export and import as it does the export and import in single shot from the source to destination. Also, the file system space is not needed to accommodate the huge dump files as we can directly import to target using network_link. It is very amazing option with data pump. You can take the backup of source database schema from another database and you can store in dump files in target location as well.
Examples One :
SQL>  select name from v$database;
NAME
———
Production
SQL> show user
USER is “OSAMA”
SQL> select * from tab;
no rows selected
SQL> create table test1 as select * from all_objects;
Table created.
SQL> select * from tab;
TNAME                          TABTYPE  CLUSTERID
—————————— ——- ———-
test1                           TABLE
added a TNS entry (File location: $ORACLE_HOME/network/admin/tnsnames.ora) for production database in my source database box. Entry as below:

production =
   (description =
      (address =
         (protocol = tcp)
         (host = xxx.xxxx.xxx.xxx)
         (port = 1521)
      )
      (connect_data =
         (server = dedicated)
         (sid = production)
      )
   )

Make Sure you test the connection using tnsping .

Connect to source database using sqlplus and create a database link to production database with osama user
SQL> create database link production connect to osama identified by osama using ‘production’;
Database link created.
SQL> select * from tab@production
  2  ;
TNAME                          TABTYPE  CLUSTERID
—————————— ——- ———-
test1                          TABLE
import the osama schema of production database to source database without dumpfile(Run it From Source)
 
$ impdp osama/osama directory=network logfile=osama.log network_link=production
Import: Release 11.2.0.3.0 – 64bit Production on Tuesday, 24 July, 2012 01:30:35
Copyright (c) 2003, 2007, Oracle.  All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Starting “OSAMA”.”SYS_IMPORT_SCHEMA_01″:  OSAMA/******** directory=exp_dir logfile=impnetworkscott.log network_link=prod8
Estimate in progress using BLOCKS method…
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 12 MB
Processing object type SCHEMA_EXPORT/USER
ORA-31684: Object type USER:”OSAMA” already exists
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
. . imported “OSAMA”.”TEST1″                      11222 rows

Example Two :
we will export  schema from source database from target machine. You can store the dump in files.
 From Source Run (Copy to dump to folder network)
$ expdp osama/osama directory=network dumpfile=osama.dmp logfile=osama.log network_link=production
Export: Release 11.2.0.3.0 – 64bit Production on Tuesday, 24 July, 2012 02:05:09
Copyright (c) 2003, 2007, Oracle.  All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Starting “OSAMA”.”SYS_EXPORT_SCHEMA_01″:  osama/******** directory=test dumpfile=osama.dmp logfile=osama.log network_link=production
Estimate in progress using BLOCKS method…
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 12 MB
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
. . exported “OSAMA”.”TEST1″                     9.496 MB   11222rows
Master table “osama”.”SYS_EXPORT_SCHEMA_01″ successfully loaded/unloaded
******************************************************************************
Also Check
1-Ronny Egners Blog

Enjoy 

Osama Mustafa

Export Data Bump , Import Data Bump In Oracle

Oracle Data Pump is a newer, faster and more flexible alternative to the “exp” and “imp” utilities used in previous Oracle versions. In addition to basic import and export functionality data pump provides a PL/SQL API and support for external tables.

Steps :

1- Create Oracle Directory 

In Sql Plus (Conn /as sysdba)

CREATE OR REPLACE DIRECTORY "Dir-name"  AS "Dir-path";
GRANT READ, WRITE ON DIRECTORY "Dir-path" TO "username";
2- Some Examples : 
CREATE OR REPLACE DIRECTORY test_dir AS '/u01/app/oracle/oradata/';
GRANT READ, WRITE ON DIRECTORY test_dir TO scott;
 
 
The TABLES parameter is used to specify the tables that are to be exported. The following is an example of the table export and import syntax.

expdp scott/tiger@db10g tables=EMP,DEPT directory=TEST_DIR 
dumpfile=EMP_DEPT.dmp logfile=expdpEMP_DEPT.log

impdp scott/tiger@db10g tables=EMP,DEPT directory=TEST_DIR 
dumpfile=EMP_DEPT.dmp logfile=impdpEMP_DEPT.log
 
 
The FULL parameter indicates that a complete database export is required. The following is an example of the full database export and import syntax.

expdp system/password@db10g full=Y directory=TEST_DIR 
dumpfile=DB10G.dmp logfile=expdpDB10G.log

impdp system/password@db10g full=Y directory=TEST_DIR 
dumpfile=DB10G.dmp logfile=impdpDB10G.log
 

You can Use For more information :

"expdp help=y"


Or 

"impdb help=y"