Background Processes in Oracle

Background Process:

• Database writer (DBWR): Writes modified blocks from database buffer cache to the datafile.
• Log Writer (LGWR): Writes redo log entries to disk.
• Check Point: At specific times all modified databases buffers in the SGA are written to the data files by DBWR. This event is called Checkpoint.
• System Monitor (SMON): Performs instance recovery at instance startup
• Process Monitor (PMON): Performs process recovery when user process fails
• Archiver (ARCH): Copies on line redo log files to archival storage when they are full
• Dispatcher: For multi threaded server for each request one dispatcher process
• Lock: For parallel server mode for inter instance locking