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
******************************************************************************
Osama Mustafa
Technology Geek 