Wednesday 11 September 2013

Data Pump

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.


For the examples to work we must first unlock the SCOTT account and create a directory object it can access. The directory object is only a pointer to a physical directory, creating it does not actually create the physical directory on the file system of the database server.
CONN / AS SYSDBA
ALTER USER scott IDENTIFIED BY tiger ACCOUNT UNLOCK;

CREATE OR REPLACE DIRECTORY test_dir AS '/u01/app/oracle/oradata/';
GRANT READ, WRITE ON DIRECTORY test_dir TO scott;

Existing directories can be queried using the ALL_DIRECTORIES view.
Note. Data Pump is a server-based technology, so it typically deals with directory objects pointing to physical directories on the database server. It does not write to the local file system on your client PC.

Table Exports/Imports

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
For example output files see expdpEMP_DEPT.log and impdpEMP_DEPT.log.
The TABLE_EXISTS_ACTION=APPEND parameter allows data to be imported into existing tables.


Schema Exports/Imports

The OWNER parameter of exp has been replaced by the SCHEMAS parameter which is used to specify the schemas to be exported. The following is an example of the schema export and import syntax.
expdp scott/tiger@db10g schemas=SCOTT directory=TEST_DIR dumpfile=SCOTT.dmp logfile=expdpSCOTT.log

impdp scott/tiger@db10g schemas=SCOTT directory=TEST_DIR dumpfile=SCOTT.dmp logfile=impdpSCOTT.log
For example output files see expdpSCOTT.log and impdpSCOTT.log.

Database Exports/Imports

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
For an example output file see expdpDB10G.log.

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