The capture process
Trail Files
Datapump
Server Collector
Apply Processes
Capture Process :
Extracts committed data from online redo logs
Status of extract Process->
stopped
starting
running
abended
Trail files :
GG converts captured data to cononical format which is written to trail files.
Note : A dedicated Check point keep tracks of data being written to the trail files.
Datapump :
DP is an additional extract process sends data in large blocks across a TCP/IP Network.
Server Collector :
Runs on target system and accepts data from source to reassemble the data and write to a remote trail file.