NETWORK_LINK

Default: There is no default

Purpose

Enables an import from a (source) database identified by a valid database link. The data from the source database instance is written directly back to the connected database instance.

Syntax and Description

NETWORK_LINK=source_database_link

The NETWORK_LINK parameter initiates an import via a database link. This means that the system to which the impdp client is connected contacts the source database referenced by the source_database_link, retrieves data from it, and writes the data directly to the database on the connected instance. There are no dump files involved.

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.

When you perform a network import using the transportable method, you must copy the source data files to the target database before you start the import.

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

This parameter is required when any of the following parameters are specified: FLASHBACK_SCN, FLASHBACK_TIME, ESTIMATE, TRANSPORT_TABLESPACES, or TRANSPORTABLE.

Caution:

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

Restrictions

  • The Import NETWORK_LINK parameter is not supported for tables containing SecureFiles that have ContentType set or that are currently stored outside of the SecureFiles segment through Oracle Database File System Links.

  • Network imports do not support the use of evolved types.

  • Network imports do not support LONG columns.

  • 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).

  • If the USERID that is executing the import job has the DATAPUMP_IMP_FULL_DATABASE role on the target database, then that user must also have the DATAPUMP_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.

  • Network mode import does not use parallel query (PQ) slaves. See "Using PARALLEL During a Network Mode Import".

  • When transporting a database over the network using full transportable import, 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 import, 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.

Example

In the following example, the source_database_link would be replaced with the name of a valid database link.

> impdp hr TABLES=employees DIRECTORY=dpump_dir1
NETWORK_LINK=source_database_link EXCLUDE=CONSTRAINT

This example results in an import of the employees table (excluding constraints) from the source database. The log file is written to dpump_dir1, specified on the DIRECTORY parameter.

See Also: