NETWORK_LINK

Default: There is no default

Purpose

Enables an export from a (source) database identified by a valid database link. The data from the source database instance is written to a dump file set on the connected database instance.

Syntax and Description

NETWORK_LINK=source_database_link

The NETWORK_LINK parameter initiates an export using a database link. This means that the system to which the expdp client is connected contacts the source database referenced by the source_database_link, retrieves data from it, and writes the data to a dump file set back on the connected system.

The source_database_link provided must be the name of a database link to an available database. If the database on that instance does not already have a database link, then you or your DBA must create one using the SQL CREATE DATABASE LINK statement.

If the source database is read-only, then the user on the source database must have a locally managed temporary tablespace assigned as the default temporary tablespace. Otherwise, the job will fail.

Caution:

If an export operation is performed over an unencrypted network link, then all data is exported as clear text even if it is encrypted in the database. See Oracle Database Security Guide for more information about network security.

Restrictions

  • The only types of database links supported by Data Pump Export are: public, fixed user, and connected user. Current-user database links are not supported.

  • Network exports do not support LONG columns.

  • When transporting a database over the network using full transportable export, tables with LONG or LONG RAW columns that reside in administrative tablespaces (such as SYSTEM or SYSAUX) are not supported.

  • When transporting a database over the network using full transportable export, auditing cannot be enabled for tables stored in an administrative tablespace (such as SYSTEM and SYSAUX) if the audit trail information itself is stored in a user-defined tablespace.

  • When operating across a network link, Data Pump requires that the source and target databases differ by no more than two versions. For example, if one database is Oracle Database 12c, then the other database must be 12c, 11g, or 10g. Note that Data Pump checks only the major version number (for example, 10g,11g, 12c), not specific release numbers (for example, 12.1,10.1, 10.2, 11.1, or 11.2).

Example

The following is an example of using the NETWORK_LINK parameter. The source_database_link would be replaced with the name of a valid database link that must already exist.

> expdp hr DIRECTORY=dpump_dir1 NETWORK_LINK=source_database_link
  DUMPFILE=network_export.dmp LOGFILE=network_export.log

See Also: