Instantiation Using the Transportable Tablespace

In this method, the tablespace has to be self-contained and should contain only the objects that are of interest for replication. This is usually a very fast method, which makes it an appropriate option for dealing with large tables.

First make the tablespace read-only; then export the metadata with the parameter transport_tablespace set to the desired tablespace. Copy both the data file supporting the tablespace and the Meta data dump to the destination database. At the destination site, import the Meta data dump files and attach the data file in order to access the tablespace and the objects at the destination database.

More details of the instantiation, with examples, are covered in later chapters. The next section presents details about the session tags that control the replication process.

Streams Tags

Streams Tags are useful components of the Streams replication process because they control the behavior of the Streams clients.  With the help of these tags, the DBAs will be able to exercise fine control over the replication process. The tags help to exclude data changes from propagation and from the apply activity.

Tags are always associated with entries in the redo log file. The data type of the tag is RAW. By default, when a user or application generates redo entries, the value of the tag is NULL for each entry. A NULL tag consumes no space in the redo entry. For entries that are not NULL, the size limit for a tag value is 2,000 bytes.