Acronym
| Process Name |
Description |
Required for basic DB operation |
Started by default |
New in this release |
|
| ABMR |
Auto BMR Background Process |
Coordinates execution of tasks such as filtering duplicate block media recovery requests and performing flood control. |
No |
No |
No |
| APnn |
Logical Standby / Streams Apply Process Coordinator Process |
Obtains transactions from the reader server and passes them to apply servers |
No |
No |
No |
| ARC 0..t |
Archiver Process (30 possible) |
Copies the redo log files to archival storage when they are full or an online redo log switch occurs |
No |
No |
No |
| BMRn |
Automatic Block Media Recovery Slave Pool Process |
Fetches blocks from a real-time readable standby database |
No |
No |
No |
| BW nn |
Database Writer Process (20 possible) |
Writes modified blocks from the database buffer cache to the
data files. The names of the 37th through 100th Database Writer
Processes are BW36-BW99. See DBWn for more information on these
processes. |
Yes |
Yes |
Yes |
| CJQ0 |
Job Queue Coordinator Process |
Spawns slave processes (Jnnn) to execute jobs in the queue. |
No |
Yes |
No |
| CKPT |
Checkpoint Process |
Signals DBWn at checkpoints and updates all the data files
and control files of the database to indicate the most recent checkpoint |
Yes |
Yes |
No |
| CPnn |
Database Capture Process |
Captures database changes from the redo log by using the infrastructure of LogMiner. |
No |
No |
No |
| CSnn |
Streams Propagation Sender Process |
Sends LCRs to a propagation receiver. |
No |
No |
No |
| CSnn |
I/O Calibration Process |
Issues I/Os to storage as part of storage calibration. There is one slave process per CPU on each node of the database. |
Yes |
Yes |
No |
| CTWR |
Change Tracking Writer Process |
Tracks changed data blocks as part of the Recovery Manager block change tracking feature |
No |
No |
No |
| DBRM |
Database Resource Manager Process |
Sets resource plans and performs other Resource Manager tasks. |
No |
Yes |
No |
| DBW 0..j |
Database Writer Process |
Writes modified blocks from the database buffer cache to the
data files. There can be 1 to 100 Database Writer Processes. The names
of the first 36 Database Writer Processes are DBW0-DBW9 and DBWa-DBWz.
The names of the 37th through 100th Database Writer Processes are
BW36-BW99. |
Yes |
Yes |
No |
| DIA0 |
Diagnostic Process 0 (although 10 possible, only 0 is currently used) |
Responsible for hang detection and deadlock resolution. Triggers DIAG to perform diagnostic tasks. |
Yes |
Yes |
No |
| DIAG |
Diagnostic Capture Process |
Performs diagnostic dumps and executes global oradebug commands. |
Yes |
Yes |
No |
| DMnn |
Data Pump Master Process |
Coordinates the Data Pump job tasks performed by Data Pump worker processes and handles client interactions. |
No |
No |
No |
| Dnnn |
Dispatcher Process |
In a Shared Server configuration, dispatchers place connection requests in a connection request queue. |
No |
Yes |
No |
| DWnn |
Data Pump Worker Process |
Performs Data Pump tasks as assigned by the Data Pump Master Process. |
No |
No |
No |
| EMNC |
EMON Coordinator Process |
Coordinates the event management and notification activity in
the database, including Streams Event Notifications, Continuous Query
Notifications, and Fast Application Notifications. Spawns Ennn
processes. |
No |
No |
No |
| Ennn |
EMON Slave Process |
Performs database event management and notifications. |
No |
No |
No |
| FBDA |
Flashback Data Archiver Process |
Archives historical rows for tracked tables into flashback data archives and manages archive space, organization, and retention |
No |
No |
No |
| FMON |
File Mapping Monitor Process |
Spawns FMPUTL, an external non-Oracle Database process that
communicates with the mapping libraries provided by storage vendors.
Responsible for managing the mapping information. |
No |
No |
No |
| GEN0 |
General Task Execution Process |
Performs required tasks including SQL and DML. |
Yes |
Yes |
No |
| Innn |
Disk and Tape I/O Slave Process |
Serves as an I/O slave process spawned on behalf of DBWR, LGWR, or an RMAN backup session. |
No |
No |
No |
| Jnnn |
Job Queue Slave Processes |
Processes jobs in the queue. Spawned by CJQ0. |
No |
Yes |
No |
| LGn |
Log Writer Slave |
On multiprocessor systems, LGWR creates slave processes to
improve the performance of writing to the redo log. LGWR slaves are not
used when there is a SYNC standby destination. |
No |
No |
Yes |
| LGWR |
Log Writer Process |
Writes the log buffer out to the redo logs. |
Yes |
Yes |
No |
| Lnnn |
Pooled Server Process |
Handles client requests in Database Resident Connection Pooling. |
No |
No |
No |
| LREG |
Listener Registration Process |
LREG notifies the listeners about instances, services, handlers, and endpoint. |
Yes |
Yes |
Yes |
| MMAN |
Memory Manager Process |
Serves as the SGA Memory Broker and coordinates the sizing of the memory components. |
No |
Yes |
No |
| MMNL |
Manageability Monitor Lite Process |
Performs frequent and lightweight manageability-related tasks, such as session history capture and metrics computation. |
No |
Yes |
No |
| MMON |
Manageability Monitor Process |
Collects statistics for the Automatic Workload Repository. |
No |
Yes |
No |
| Mnnn |
MMON Slave Process |
Performs manageability tasks on behalf of MMON. |
No |
No |
No |
| MSnn |
LogMiner Worker Process |
Reads redo log files and translates and assembles into transactions. |
No |
No |
No |
| Nnnn |
Connection Broker Process |
Monitors idle connections and hands off active connections in Database Resident Connection Pooling |
No |
No |
No |
| OFSD |
Oracle File Server Background Process |
This background process listens for new file system requests,
both management (like mount, unmount, and export) and I/O requests, and
executes them using Oracle threads. |
Yes |
Yes |
No |
| PMON |
Process Monitor |
Recovers failed process resources. If Shared Server
architecture is used, PMON monitors and restarts any failed dispatcher
or server processes. |
Yes |
Yes |
No |
| Pnnn |
Parallel Query Slave Process |
Started and stopped as needed to participate in parallel query operations. |
No |
No |
No |
| PRnn |
Parallel Recovery Process |
Performs tasks assigned by the coordinator process performing parallel recovery |
No |
No |
No |
| PSP0 |
Process Spawner Process |
Starts and stops Oracle processes. Reduces workload of RBAL by starting / stopping ASM rebalance slaves. |
No |
Yes |
No |
| RCBG |
Result Cache Background Process |
Supports SQL query and PL/SQL function result caches. |
No |
No |
No |
| RECO |
Recoverer Process |
Resolves failures involving distributed transactions. |
No |
Yes |
No |
| RM |
RAT Masking Slave Process |
This background process is used with Data Masking and Real Application Testing. |
No |
Yes |
Yes |
| RPnn |
Capture Processing Worker Process |
Processes a set of workload capture files. |
No |
No |
No |
| RPOP |
Instant Recovery Repopulation Daemon |
Responsible for re-creating and/or repopulating data files
from snapshot files and backup files. The RPOP process is responsible
for re-creating and repopulating data files from snapshots files. It
works with the instant recovery feature to ensure immediate data file
access. The local instance has immediate access to the remote snapshot
file's data, while repopulation of the recovered primary data files
happens concurrently. Any changes in the data are managed between the
instance's DBW processes and RPOP to ensure the latest copy of the data
is returned to the user. |
No |
No |
Yes |
| RVWR |
Recovery Writer Process |
Writes flashback data to flashback database logs in the flash recovery area. |
No |
No |
No |
| SAnn |
SG Allocator |
A small fraction of SGA is allocated during instance startup.
The SAnn process allocates the rest of SGA in small chunks. The process
exits upon completion of SGA allocation. |
No |
Yes |
Yes |
| SMCO |
Space Management Coordinator Process |
Coordinates the execution of various space management related tasks, such as proactive space allocation and space reclamation. |
No |
Yes |
No |
| SMON |
System Monitor Process |
Performs critical tasks such as instance recovery and dead
transaction recovery, and maintenance tasks such as temporary space
reclamation, data dictionary cleanup, and undo tablespace management |
Yes |
Yes |
No |
| Snnn |
Shared Server Process |
In a Shared Server configuration, shared servers check a
connection request queue (populated by dispatchers) and services the
connection requests. |
No |
Yes |
No |
| VKRM |
Virtual Scheduler for Resource Manager Process |
Serves as centralized scheduler for Resource Manager activity. |
No |
Yes |
No |
| VKTM |
Virtual Keeper of Time Process |
Responsible for providing a wall-clock time (updated every
second) and reference-time counter (updated every 20ms and available
only when running at elevated priority). |
Yes |
Yes |
No |
| Wnnn |
Space Management Slave Process |
These are slave processes spawned by SMCO to execute space management tasks. |
No |
Yes |
No |
