Database Writer (DBWn)
:It is responsible to redo log buffer management. Almost all activities against the database are tracked in the online redo logs. As transaction are initiated and
eventually committed or rolled back, a record of this activity is written to these
log files.
Checkpoint (CKPT):
A checkpoint is an event that flushes modified data from buffer cache to disk and updates control file and data files. The CKPT process updates header of data files and control files and
DBWn writes actual blocks to file. Checkpoint occurs automatically when an
online redo log file fills (log switch).
System Monitor (SMON):
At startup, SMON’s job is to ensure that all the database files are consistent and
perform recovery if required. There is also an assortment of other cleanup
activities that may need to be done, which are SMON’s responsibility. The
SMON process by itself checks every so often to see whether there are any tasks
waiting for its attention.
Process Monitor (PMON):
Cleans up failed user processes and frees all resources used by failed process.
Archiver (ARCn):
It automatically saves copies of redo logs in a DBA specified storage location
when media recovery is enabled.
Recover (RECO):
Is used with distributed transaction to resolve failure.
:It is responsible to redo log buffer management. Almost all activities against the database are tracked in the online redo logs. As transaction are initiated and
eventually committed or rolled back, a record of this activity is written to these
log files.
Checkpoint (CKPT):
A checkpoint is an event that flushes modified data from buffer cache to disk and updates control file and data files. The CKPT process updates header of data files and control files and
DBWn writes actual blocks to file. Checkpoint occurs automatically when an
online redo log file fills (log switch).
System Monitor (SMON):
At startup, SMON’s job is to ensure that all the database files are consistent and
perform recovery if required. There is also an assortment of other cleanup
activities that may need to be done, which are SMON’s responsibility. The
SMON process by itself checks every so often to see whether there are any tasks
waiting for its attention.
Process Monitor (PMON):
Cleans up failed user processes and frees all resources used by failed process.
Archiver (ARCn):
It automatically saves copies of redo logs in a DBA specified storage location
when media recovery is enabled.
Recover (RECO):
Is used with distributed transaction to resolve failure.
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