Note the following functionalities of various background processes:
1. Record the checkpoint information in data file headers.
2. Perform recovery at instance startup.
3. Cleanup unused temporary segments.
4. Free the resources used by a user process when it fails.
5. Dynamically register database services with listeners.
6. Monitor sessions for idle session timeout.
Which option has the correct functionalities listed for a background process?
A.
Archiver Process (ARCn): 1, 2, 5
B.
System Monitor Process (SMON): 1, 4, 5
C.
Process Monitor Process (PMON): 4, 5, 6
D.
Database Writer Process (DBWn): 1, 3, 4
Process Monitor(PMON):performs process cleanup when a user process fails
The process monitor (PMON) monitors the other background processes and performs process recovery when a server or dispatcher process terminates abnormally.
PMON is responsible for cleaning up the database buffer cache and freeing resources that the client process was using.
For example, PMON resets the status of the active transaction table, releases locks that are no longer required, and removes the process ID from the list of active processes.
PMON also registers information about the instance and dispatcher processes with the Oracle Net listener .
When an instance starts, PMON polls the listener to determine whether it is running. If the listener is running, then PMON passes it relevant parameters. If it is not running, then PMON periodically attempts to contact it.