Object Instantiation and Streams

• prepare_schema_instantiation – This procedure prepares all of the database objects in a schema and all database objects added to the schema in the future for instantiation. This method is useful when the goal is to maintain a total replicated schema at the destination database. In a single instantiation step, all the existing objects are instantiated
   

• prepare_global_instantiation – This procedure prepares all of the database objects in a database and all database objects added to the database in the future for instantiation.

The chapters of this book on configuration contain additional details and examples, including the syntax of the procedures and arguments.

These procedures record the SCN value below which changes to an object cannot be applied at the destination database. The above methods need to be used appropriately before the SCN number is recorded and specified to the Apply process at the destination database. Rules must be added to the positive rule set for the Capture process before the database objects are prepared for instantiation.

As noted earlier, Oracle provides multiple methods for performing instantiation. These other methods include the traditional export/import method, newly available data pump export/import method, transportable tablespace method and the RMAN utility. Each of these methods works very well. However, all of these methods may not work in all situations. The following some general considerations to follow when selecting a method for instantiation:

• If replication is being setup between databases located on different operating systems or character sets, the export/import becomes the choice tool. For example, by using export/import, an object can be dumped or exported from the source database residing on a Solaris host and imported into the destination database residing on a Linux host.