Database Reference
In-Depth Information
Tip
When replicating entire databases, also consider using the rmaN duplicate database functionality.
DataBaSe LINK VS. NetWOrK_LINK
Don't confuse exporting while connected to a remote database over a database link with exporting using the
NETWORK_LINK parameter. When exporting while connected to a remote database via a database link, the objects
being exported exist in the remote database, and the dump file and log file are created on the remote server in
the directory specified by the DIRECTORY parameter. For instance, the following command exports objects in the
remote database and creates files on the remote server:
$ expdp mv_maint/foo@shrek2 directory=dp_dir dumpfile=sales.dmp
In contrast, when you export using the NETWORK_LINK parameter, you are creating dump files and log files locally,
and the database objects being exported exist in a remote database; for example,
$ expdp mv_maint/foo network_link=shrek2 directory=dp_dir dumpfile=sales.dmp
Copying Data Files
Oracle provides a mechanism for copying data files from one database to another, in conjunction with using Data
Pump to transport the associated metadata. This is known as the transportable tablespace feature. The amount of
time this task requires depends on how long it takes you to copy the data files to the destination server. This technique
is appropriate for moving data in DSS and data warehouse environments.
transporting tablespaces can also be used (in conjunction with the rmaN CONVERT TABLESPACE command) to
move tablespaces to a destination server that has a platform different from that of the host.
Tip
Follow these steps to transport tablespaces:
1.
Ensure that the tablespace is self-contained. These are some common violations of the
self-contained rule:
An index in one tablespace can't point to a table in another tablespace that isn't in the set
of tablespaces being transported.
A foreign key constraint is defined on a table in a tablespace that references a primary key
constraint on a table in a tablespace that isn't in the set of tablespaces being transported.
Run the following check to see if the set of tablespaces being transported violates any of the self-contained rules:
SQL> exec dbms_tts.transport_set_check('INV_DATA,INV_INDEX', TRUE);
Now, see if Oracle detected any violations:
SQL> select * from transport_set_violations;
 
 
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