Extra Attributes

The include_extra_attribute procedure in the dbms_capture_adm package can be used to instruct a Capture process to capture one or more extra attributes in addition to those presented earlier. The optional attributes are:

• serial# - This is the serial number of the session that performed the change captured in the LCR.
   

• session# - This is the identifier of the session that performed the change captured in the LCR.
   

• thread# - This is the thread number of the instance in which the change captured in the LCR was performed. Typically, the thread number is relevant only in a Real Application Clusters environment.
   

• tx_name - This is the name of the transaction that includes the LCR.
   

• username - This is the name of the user who performed the change captured in the LCR.

Rules Engine and Rules

Rules play an important role in configuring and conducting the streams data flow.  A Rule is the Streams object which applies logic to determine if the change is to be captured or not, to be propagated or not and to be applied or not. In this manner, rules play a key role in filtering the changes. A faulty rule definition can create big administrative overhead that will require troubleshooting.