Oracle Process architecture

The Oracle RDBMS typically relies on a group of processes running simultaneously in the background and interacting to further and monitor database operations. Such processes (and their standard abbreviations) can include:

• Archiver processes (ARCn)
• Checkpoint process (CKPT)
• Database writer processes (DBWn)
• Dispatcher processes (Dnnn): multiplex server-processes on behalf of users
• Memory-manager process (MMAN): used for internal database tasks such as Automatic Shared Memory Management
• Job-queue processes (CJQn)
• Log-writer process (LGWR)
• Log-write network-server (LNSn): transmits redo logs in Data Guard environments
• Logical standby coordinator process (LSP0): controls Data Guard log-application
• Media-recovery process (MRP): detached recovery-server process
• Memory-monitor process (MMON)
• Memory-monitor light process (MMNL): gathers and stores Automatic Workload Repository (AWR) data
• Process-monitor process (PMON)
• Process-spawner (PSP0): spawns Oracle processes
• Queue-monitor processes (QMNn)
• Recoverer process (RECO)
• Remote file-server process (RFS)
• Shared server processes (Snnn): serve client-requests
• system monitor process (SMON)