Object Instantiation and Streams

• Export and import using the Data Pump utility is recommended as it is faster and more efficient than the traditional export and import method.  However, the Data Pump utilities cannot be used when dealing with replication between 10g release database and 9i release database.
   

• The RMAN duplicate command cannot be used when the data is being moved to a database residing on a different operating system.  However, when the RMAN utility can be used, the instantiation process is generally faster than using the export/import method. This becomes important when there are large data volumes to be dealt with.

The following section provides an overview of these methods.

Instantiation by the Data Pump Export and Import Method

In this method, Data Pump export can be used to export table(s) or schema(s) from the source database. Typically, the expdp utility is used to export the schema or objects. The flashback_scn export parameter is specified in the expdp command line. The current SCN of the source database is specified as the flashback_scn.

Copy the dump file to the destination database and import the tables or schema using the impdp utility. Once the tables or schema are imported, the data is synchronized between the source and destination databases. The destination is now ready to accept the changes above this SCN value.

Traditional export and import can also be used to set up the tables at the destination database and set up the instantiation. In this case, the streams_instantiation parameter should be used with a value of ‘Y’.