One process will start for each NUMA node on target machines. Performs Oracle ASM disk scrubbing repair operation. Possible processes are ARB0-ARB9 and ARBA. When a process submits a block media recovery request to ABMR, it dynamically spawns slave processes (BMRn) to perform the recovery. The pooled server process performs network communication directly on the client connection and processes requests until the client releases the server. It also handles checkpoints, file open synchronization, and logging of Block Written records. You can disable these processes by setting the parameter to 0. A minimum of three MSnn processes work as a group to provide transactions to a LogMiner client, for example, a logical standby database or a database capture. The VKTM timer service centralizes time tracking and offloads multiple timer calls from other clients. Query V$STREAMS_APPLY_SERVER for information about the apply server background process. The names for CRnn processes will have the format CR0n__. When an apply server places a transaction in the error queue and commits, this transaction also has been applied. PMAN monitors, spawns, and stops the following as needed. Database instances, XStream Outbound Server, Sets resource plans and performs other tasks related to the Database Resource Manager. These membership changes are required for the file system to maintain file system consistency within the cluster. The LSP1 process is spawned on a logical standby database that is intended to become the new primary database. Writes redo entries to the online redo log. Database instances, Logical Standby, Oracle Streams, XStream Outbound servers, Oracle GoldenGate, Monitors idle connections and hands off active connections in Database Resident Connection Pooling, Transfers redo from current online redo logs to remote standby destinations configured for SYNC transport. This is a fully automated process, that basically does a diff on many important sys dictionary objects from this release with the previous one. These slaves are terminated after the online redo logs are cleared, and the session does not persist. The shared server then reads the data from the virtual circuit and performs the database work necessary to complete the request. IPC0: - IPC Service Background Process - Common background server for basic messaging and RDMA primitives based on IPC (Inter-process communication) methods. When an apply server places a transaction in the error queue and commits, this transaction also has been applied. I/O errors can be emulated on Oracle ASM disk I/O through named events. See "THREADED_EXECUTION" for more information about the THREADED_EXECUTION initialization parameter. The pooled server process performs network communication directly on the client connection and processes requests until the client releases the server. The coordinator process name is ASnn, where nn can include letters and numbers. Performs Oracle ASM post-rebalance activities. GCRn processes are transient slaves that are started and stopped as required by LMHB to perform synchronous or resource intensive tasks. The process handles all requests for resources other than data blocks. Optionally, a set of AUs can be chosen for error emulation. These background slave processes perform tasks on behalf of a coordinating process running in another cluster instance. FMON is started by the database whenever the FILE_MAPPING initialization parameter is set to true. In the shared server architecture, clients connect to a dispatcher process, which creates a virtual circuit for each connection. Wnnn processes are utilized by the IMCO background process for prepopulation of in-memory enabled objects with priority LOW/MEDIUM/HIGH/CRITICAL, and for repopulation of in-memory objects. Here are some of the most important Oracle background processes: ARCH - (Optional) Archive process writes filled redo logs to the archive log location (s). Slave processes are numbered from 0 to the PARALLEL_MAX_SERVERS setting. If you try to run XA global transactions with these processes disabled, an error is returned. GMON monitors all the disk groups mounted in an Oracle ASM instance and is responsible for maintaining consistent disk membership and status information. PMON periodically performs cleanup of all the following: Detached transactions that have exceeded their idle timeout, Detached network connections which have exceeded their idle timeout. A logical standby database becomes a primary database because of switchover or failover. Schedules transactions for Data Guard SQL Apply. ASMB also runs with Oracle Cluster Registry on Oracle ASM. The JOB_QUEUE_PROCESSES initialization parameter specifies the maximum number of processes that can be created for the execution of jobs. Resolves distributed transactions that are pending because of a network or system failure in a distributed database. There can be up to 36 of these slave processes (LDD0-LDDz). The IMCO background process initiates population (prepopulation) of in-memory enabled objects with priority LOW/MEDIUM/HIGH/CRITICAL. The V$PROCESS view lists database processes running in these container processes. These slave processes are transient as they are started on demand and they can be shutdown when no longer needed. There is one slave process per CPU on each node of the database. Performs manageability tasks on behalf of MMON. Performs Oracle ASM disk scrubbing check operation. The dispatcher processes are enabled by the ENABLE_DNFS_DISPATCHER initialization parameter. VKTM publishes two sets of time: a wall clock time using a seconds interval and a higher resolution time (which is not wall clock time) for interval measurements. In an Oracle Streams combined capture and apply optimization, the propagation sender sends LCRs directly to the propagation receiver to improve performance. For examples, LCKn manages library and row cache requests. The RPOP process is responsible for re-creating and repopulating data files from snapshots files. An Oracle Database background process is defined as any process that is listed in V$PROCESS and has a non-null value in the PNAME column. The process is slightly different depending on the type of database. RPnn are worker processes spawned by calling DBMS_WORKLOAD_REPLAY.PROCESS_CAPTURE(capture_dir,parallel_level). When you have multiple instances on a UNIX server and need to release a semaphore set for an Oracle database, you must first determine which semaphore set belongs to your crippled instance. FBDA maintains metadata on the current rows and tracks how much data has been archived. I/O slave process can be configured on platforms where asynchronous I/O support is not available. By default, parallel_level is null. NSVn is created when a Data Guard broker configuration is enabled. These tasks include preallocating space into locally managed tablespace and SecureFiles segments based on space usage growth analysis, and reclaiming space from dropped segments. These processes work on the system notifications in parallel, offering a capability to process a larger volume of notifications, a faster response time, and a lower shared memory use for staging notifications. Performs or schedules many manageability tasks. Concepts and Oracle Database Net In an Oracle ASM instance, the ASMB process runs when the ASMCMD cp command runs, or when a database instance first starts if the server parameter file is stored in Oracle ASM. The database writes the following message to the alert log: WARNING: AQ_TM_PROCESSES is set to 0. Unnn processes are database container operating system processes where database backgrounds processes like SMON, CJQ0, and database foreground processes run. This process receives, processes, and sends GCS requests, block transfers, and other GCS-related messages. Instance Membership Recovery Slave Process, Performs synchronous tasks on behalf of LMON, The IMR0 background process performs the Instance Member Recovery synchronous operations on behalf of LMON, Oracle RAC, Database instances, Oracle ASM instances, Performs Data Guard broker communication among instances in an Oracle RAC environment. When instructed by the user, FMON builds mapping information and stores it in the SGA, refreshes the information when a change occurs, saves the information to the data dictionary, and restores it to the SGA at instance startup. The LSP2 process is created as needed during startup of SQL Apply to update the list of objects that are protected by the database guard. There can be as many NSVn processes (where n is 0- 9 and A-U) created as there are databases in the Data Guard broker configuration. After the shared server completes the client request, the server releases the virtual circuit back to the dispatcher and is free to handle other clients. The possible processes are SCC0-SCC9. 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. The DB_WRITER_PROCESSES initialization parameter specifies the number of Database Writer Processes. Manages the rolling migration procedure for an Oracle ASM cluster. DMON also monitors the health of the broker configuration and ensures that every database has a consistent description of the configuration. Host processes where database processes execute as threads. The External Properties column lists the type of instance in which the process runs. IPC0 - IPC Service Background Process Common background server for basic messaging and RDMA primitives based on IPC (Inter-process communication) methods. The time for the round trip is measured and collected. NSSn can run as multiple processes, where n is 1-9 or A. VKRM manages the CPU scheduling for all managed Oracle processes. The process detects instance transitions and performs reconfiguration of GES and GCS resources. Global Enqueue Service Daemon Helper Slave, Helps the LMDn processes with various tasks. See Also: Oracle Database Onnn slave processes are spawned on demand. This process is automatically started on instance startup. ASMB also runs with Oracle Cluster Registry on Oracle ASM. In general, ACMS is limited to small, nonblocking state changes for a limited set of cross-instance operations. This process is started only if Oracle Real Application Clusters (Oracle RAC) is enabled. Coordinates execution of tasks such as filtering duplicate block media recovery requests and performing flood control. Data Guard Broker Fast Start Failover Pinger Process, Maintains fast-start failover state between the primary and target standby databases. These slaves are started by setting the corresponding slave enable parameter in the server parameter file. Performs Oracle ASM disk scrubbing verify operation. The ONLINE operation is handled by XDWK. Processes fence requests for RDBMS instances which are using Oracle ASM instances. Mnnn performs manageability tasks dispatched to them by MMON. PO is approved as if using online mode Issue can be seen in the following excerpt from the wfstat.sql script output : Starting with Oracle Database 19c, IMXT (In-Memory External Table) segments are dropped by the IMCO background process. GMON must be highly available and cannot wait. AQPC is responsible for performing administrative tasks for AQ Master Class Processes including commands like starting, stopping, and other administrative tasks. This background process coordinates the execution of various space management tasks, including proactive space allocation and space reclamation. CJQ0 starts only as many job queue processes as required by the number of jobs to run and available resources. Maintains a connection to the Oracle ASM instance for metadata operations, Serves file system requests submitted to an Oracle instance. SMON in a non-failed instance can also perform failed instance recovery for other failed RAC instance. Tracks changed data blocks as part of the Recovery Manager block change tracking feature. The process schedules managed processes in accordance with an active resource plan. Determines which database objects will be protected by the database guard. The External Properties column lists the type of instance in which the process runs. The process is created when the DG_BROKER_START initialization parameter is set to true. You start troubleshooting an ORA-00445 error by examining your alert log and check for trace files in the bdump (background_dump_dest) directory. If a resource plan is not enabled, then this process is idle. Executions of SPA tasks created from a SQL tuning set use this slave to analyze the SQL statements of the SQL tuning set concurrently. But when I run same script in background, it hang up in background, nothing output. Maintains a connection to the Oracle ASM instance for metadata operations. Writes flashback data to the flashback logs in the fast recovery area. The ONLINE operation is handled by XDWK. These background slave processes perform tasks on behalf of a coordinating process running in another cluster instance. Monitors an Oracle RAC cluster to manage global resources. Oracle File Server Background Process Thread, This is a thread for the OFSD background process. ABMR and BMRn terminate after being idle for a long time. In this context, a background process is defined as any process that is listed in V$PROCESS and has a non-null value in the PNAME column. These processes communicate with the Oracle ASM instance. Selects jobs that need to be run from the data dictionary and spawns job queue slave processes (Jnnn) to run the jobs. Multiple MSnn processes can exists, where n is 0-9 or a-Z. See Also: Oracle Database XStream Database instances, Logical Standby, XStream Outbound servers, Oracle GoldenGate. Coordinates database event management and notifications. These dedicated set of slaves will be used to perform Direct NFS I/Os on behalf of database processes. The Mnnn processes are a pool of slave processes that can be shared by multiple MZnn processes. When the client sends data to the server, the dispatcher receives the data into the virtual circuit and places the active circuit on the common queue to be picked up by an idle shared server. The database automatically tunes the number of these processes based on the workload of XA global transactions. VBGn can run as multiple processes, where n is 0-9. Manages resources and provides resource control among Oracle RAC instances. After each process is finished processing its assigned files, it exits and informs its parent process. By default, parallel_level is null. Writes flashback data to the flashback logs in the fast recovery area. The background processes of the Oracle instance manage memory structures, asynchronously perform I/O to write data to a file on a disk, and perform general maintenance tasks. For in-memory population and repopulation, both the IMCO background process and foreground processes will utilize Wnnn slaves. INSV is created when the DG_BROKER_START initialization parameter is set to true. These tasks include preallocating space into locally managed tablespace and SecureFiles segments based on space usage growth analysis, and reclaiming space from dropped segments. When the shared server must send data to the client, the server writes the data back into the virtual circuit and the dispatcher sends the data to the client. The database starts multiple archiver processes as needed to ensure that the archiving of filled online redo logs does not fall behind. The maximum number of Pnnn processes is controlled by the initialization parameter PARALLEL_MAX_SERVERS. The Database Writer Process performs multiblock writes when possible to improve efficiency. The background processes perform maintenance tasks required to operate the database and to maximize performance for multiple users. Resolves distributed transactions that are pending because of a network or system failure in a distributed database. GMON must be highly available and cannot wait. It works with the instant recovery feature to ensure immediate data file access. 5.Process Monitor Process. Background processes consolidate functions that would otherwise be handled by multiple database programs running for each user process. In particular, they process incoming enqueue request messages and control access to global enqueues. When a process submits a block media recovery request to ABMR, it dynamically spawns slave processes (BMRn) to perform the recovery. DMON also monitors the health of the broker configuration and ensures that every database has a consistent description of the configuration.