RVWR also creates flashback logs and performs some tasks for flashback log automatic management. LGWR writes the redo log entries sequentially into a redo log file. After the job is complete, the slave processes commit and then execute appropriate triggers and close the session. One process will start for each NUMA node on target machines. Enterprise Manager Database Express, also referred to as EM Express, provides support for CDB. The ASM RBAL background process coordinates and spawns one or more of these slave processes to recover aborted ASM transactional operations. Here are some of the most important Oracle background processes: ARCH - (Optional) Archive process writes filled redo logs to the archive log location (s). 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. VKRM manages the CPU scheduling for all managed Oracle processes. GCRn processes are transient slaves that are started and stopped as required by LMHB to perform synchronous or resource intensive tasks. After looking at sp_who, Oracle does not have that ability per se. In addition to managing LogMiner and Apply processes, LSP0 is responsible for maintaining inter-transaction dependencies and appropriately scheduling transactions with applier processes. On completion of individual checkpoint requests, CKPT updates data file headers and control files to record most recent checkpoint. The propagation receiver passes the LCRs to an apply process. Any issues related to background processes should be monitored and analyzed from the trace files generated and the alert log. The slave processes start a database session as the owner of the job, execute triggers, and then execute the job. To maximize performance and accommodate many users, a multiprocess Oracle database system uses background processes. Data Guard Broker Fast Start Failover Pinger Process, Maintains fast-start failover state between the primary and target standby databases. Set PO: Workflow Processing Mode profile = Background 2. TTnn can run as multiple processes, where nn is 00 to ZZ. The database event management and notification load is distributed among the EMON slave processes. These processes exit when the instance is shut down or terminated. PMON is then responsible for coordinating cleanup performed by the CLMN process and the CLnn slaves. Each of this type of process represents a single class of work item such as AQ notification, queue monitors, and cross process. This background process coordinates the execution of various space management tasks, including proactive space allocation and space reclamation. There is one slave process per CPU on each node of the database. These container processes are created only when the THREADED_EXECUTION initialization parameter is set to TRUE. Under normal operation on non-Exadata hardware and on Exadata hardware that is not utilizing ASM volumes, these processes will not be started. Performs Data Guard broker communication among instances in an Oracle RAC environment. The RSnn processes were named RMVn in Oracle Database 12c and earlier releases. In general, ACMS is limited to small, nonblocking state changes for a limited set of cross-instance operations. The process is slightly different depending on the type of database. 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. 2.Log Writer Process. ABMR and BMRn terminate after being idle for a long time. For in-memory population and repopulation, both the IMCO background process and foreground processes will utilize Wnnn slaves. FBDA also keeps track of how far the archiving of tracked transactions has progressed. CKPT checks every three seconds to see whether the amount of memory exceeds the value of the PGA_AGGREGATE_LIMIT initialization parameter, and if so, takes the action described in "PGA_AGGREGATE_LIMIT". The capture process includes one reader server that reads the redo log and divides it into regions, one or more preparer servers that scan the redo log, and one builder server that merges redo records from the preparer servers. Each of this type of process represents a single class of work item such as AQ notification, queue monitors, and cross process. The local instance has immediate access to the remote snapshot file's data, while repopulation of the recovered primary data files happens concurrently. ABMR and BMRn terminate after being idle for a long time. Once released, the server class processes are moved to a free server pool. SQL script file: t.sql-----select sysdate from dual; quit;-----I can get result when run this command :-----sql U/P@10.224.141.137:8521/nmsb @t.sql. Manages and monitors a database that is part of a Data Guard broker configuration. Performs broker network communications between databases in a Data Guard environment. These processes handle requests for I/Os targeted at storage not locally accessible. These container processes are created only when the THREADED_EXECUTION initialization parameter is set to TRUE. Every few seconds, the process in one instance sends messages to each instance. CSnn slave processes are started on execution of the DBMS_RESOURCE_MANAGER.CALIBRATE_IO() procedure. The process is created when a Data Guard broker configuration is enabled. Coordinates the application of redo on a physical standby database. Writes redo entries to the online redo log. LSP0 is also responsible for detecting and enabling run-time parameter changes for the SQL Apply product as a whole. In previous releases, IMXT segments were dropped by foreground processes. RVWR writes flashback data from the flashback buffer in the SGA to the flashback logs. Captures database changes from the redo log by using the infrastructure of LogMiner. Symptoms Wait event "RMA: IPC0 completion sync" is in Top Timed Events in AWR report on a fresh 12.2 Real Application Cluster environment. The underlying LogMiner process name is MSnn, where nn can include letters and numbers. Redo log entries are generated in the redo log buffer of the system global area (SGA). Each server class process acts on behalf of an AQ master class process. In a database instance, the ASMB and AMBn processes enable the database instance to connect to an Oracle ASM instance in order to access Oracle ASM disk groups. These background slave processes perform tasks on behalf of a coordinating process running in another cluster instance. DMON runs for every database instance that is managed by the broker. See "THREADED_EXECUTION" for more information about the THREADED_EXECUTION initialization parameter. Handles client requests in the shared server architecture, Emulates I/O errors on Oracle ASM disks through named events. The names of the first 36 Database Writer Processes are DBW0-DBW9 and DBWa-DBWz. GMON must be highly available and cannot wait. JPn patches and updates the Java in the database classes. This means that when one of these background processes crashes, then whoever detects the process disappearance (PMON or LGWR or CLMN possibly), will shut down the instance as it cannot function normally anymore. An apply server receives the transactions from the coordinator background process, and either applies database changes in LCRs or sends LCRs or messages to apply handlers. Query V$STREAMS_APPLY_READER, V$XSTREAM_APPLY_READER, and V$GG_APPLY_READER for information about the reader server background process. The process exits upon completion of SGA allocation. This background process manages the creation of slave processes and the communication with their coordinators and peers. Manages resources and provides resource control among Oracle RAC instances. In particular, they process incoming enqueue request messages and control access to global enqueues. FBDA is also responsible for automatically managing the flashback data archive for space, organization (partitioning tablespaces), and retention. RVWR writes flashback data from the flashback buffer in the SGA to the flashback logs. In 19c, the background processes are grouped into three categories: mandatory, optional and slave background processes. CSS monitors RDBMS instances which are connected to the Oracle ASM instance and constantly doing I/Os. Performs Oracle ASM post-rebalance activities. It performs manageability tasks dispatched by MMON, which include taking Automatic Workload Repository snapshots and performing Automatic Database Diagnostic Monitor analysis. Host processes where database processes execute as threads. Performs or schedules many manageability tasks. Multiple MSnn processes can exists, where n is 0-9 or a-Z. LGnn - Log Writer Worker In addition to managing LogMiner and Apply processes, LSP0 is responsible for maintaining inter-transaction dependencies and appropriately scheduling transactions with applier processes. The maximum number of Pnnn processes is controlled by the initialization parameter PARALLEL_MAX_SERVERS. CLMN periodically performs cleanup of all the following: dead processes, killed sessions, transactions, network connections, idle sessions, detached transactions, and detached network connections that have exceeded their idle timeout. 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. Table F-1 describes Oracle Database background processes. Ships redo from current online and standby redo logs to remote standby destinations configured for ASYNC transport. These tasks include preallocating space into locally managed tablespace and SecureFiles segments based on space usage growth analysis, and reclaiming space from dropped segments. You can ask the DB which queries are running as that just a table query. The Data Pump master (control) process is started during job creation and coordinates all tasks performed by the Data Pump job. Possible processes are LCK0 and LCK1. CKPT checks every three seconds to see whether the amount of memory exceeds the value of the PGA_AGGREGATE_LIMIT initialization parameter, and if so, takes the action described in "PGA_AGGREGATE_LIMIT". 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. DMON also monitors the health of the broker configuration and ensures that every database has a consistent description of the configuration. Database instances, Database Resident Connection Pooling, Mark AU for Resynchronization Coordinator Process, Marks ASM allocation units as stale following a missed write to an offline disk. On multiprocessor systems, LGWR creates worker processes to improve the performance of writing to the redo log. DSKM performs operations related to Exadata I/O fencing and Exadata cell failure handling. This process performs the resizing of memory components on the instance. 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. Symptoms On systems where Exafusion is enabled, the IPC0 background process is seen with a high RSS (resident set size) memory usage in OS commands like "top" and "ps". STEPS The issue can be reproduced at will with the following steps: 1. Mnnn performs manageability tasks dispatched to them by MMON. Wnnn slave processes perform work on behalf of Space Management and on behalf of the Oracle In-Memory Option. XDWK gets started when asynchronous actions such as ONLINE, DROP, and ADD an Oracle ASM disk are requested by XDMG. A copy of this file is maintained by the DMON process for each of the databases that belong to the broker configuration. Database instances, Oracle ASM instances, Manages incoming remote resource requests from other instances. RVWR also creates flashback logs and performs some tasks for flashback log automatic management. Extracts and masks bind values from workloads like SQL tuning sets and DB Replay capture files. DIAG performs diagnostic dumps requested by other processes and dumps triggered by process or instance termination. These processes run only in the Oracle ASM instance. See Also: Oracle Database Administrator's Guide. When a transaction that modifies a tracked table commits, FBDA stores the pre-image of the rows in the archive. This process expels dropped disks after an Oracle ASM rebalance. The pooled server process performs network communication directly on the client connection and processes requests until the client releases the server. I can not get any result and hung up in background . 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. Recovery Users Guide, Oracle Advanced Cluster File System (Oracle ACFS) CSS Process, Tracks the cluster membership in CSS and informs the file system driver of membership changes. please give your expert advice on this when time permits.. Oracle Database - Enterprise Edition - Version 12.2.0.1 to 19.1.0.0.0 [Release 12.2 to 19] Information in this document applies to any platform. Performs automation tasks requested by XDMG. By default, parallel_level is null. Copies the redo log files to archival storage when they are full or an online redo log switch occurs. The Mnnn processes are a pool of slave processes that can be shared by multiple MZnn processes. Action Ensure that the executable image is in the correct place with the correct protections, and that there is enough memory. The shared server then reads the data from the virtual circuit and performs the database work necessary to complete the request. It also handles checkpoints, file open synchronization, and logging of Block Written records. Starting with Oracle Database 19c, IMXT (In-Memory External Table) segments are dropped by the IMCO background process. Database instances, Database Resident Connection Pooling, Mark AU for Resynchronization Coordinator Process, Marks ASM allocation units as stale following a missed write to an offline disk. The LMFC process will perform actions related to scanning the dead instance's database flash cache and claim flash blocks mastered by the dead instance. The GLOBAL_TXN_PROCESSES initialization parameter specifies the number of GTXn processes, where n is 0-9 or a-j. DMON interacts with the local database and the DMON processes of the other databases to perform the requested function. ASMB runs in Oracle ASM instances when the ASMCMD cp command runs or when the database instance first starts if the server parameter file is stored in Oracle ASM. These processes exit when the instance is shut down or terminated. Virtual Scheduler for Resource Manager Process, Serves as centralized scheduler for Resource Manager activity. Broker, Performs network communication in the shared server architecture. Concepts and Oracle Database Coordinates the execution of various space management tasks. This process handles the extraction of redo and coordinates the application of that redo on a physical standby database. If the process is specific to a particular feature, then the column names the feature. In Oracle 12c there is a total of 19 new background processes meaning that if you are running in an 11gR2 environment you will only have 92. The VKTM timer service centralizes time tracking and offloads multiple timer calls from other clients. Coordinates execution of tasks such as filtering duplicate block media recovery requests and performing flood control. The DB_WRITER_PROCESSES initialization parameter specifies the number of Database Writer Processes. Query V$PROPAGATION_SENDER for information about a propagation sender. The ACMS process works with a coordinating caller to ensure that an operation is executed on every instance in Oracle RAC despite failures. The process is created when a Data Guard broker configuration is enabled. If a resource plan is not enabled, then this process is idle. In this context, a background process is defined as any process that is listed in V$PROCESS and has a non-null value in the PNAME column. In Database Resident Connection Pooling, clients connect to a connection broker process. Performs manageability tasks for Oracle RAC. Processes fence requests for RDBMS instances which are using Oracle ASM instances. Several initialization parameters relate to shared servers. 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 coordinator process name is APnn, where nn can include letters and numbers. Query V$PROPAGATION_SENDER for information about a propagation sender. ACMS is the process in which a distributed operation is called. Table F-1 describes Oracle Database background processes. Uninstallation of APEX from a default Oracle 11gR2 database The possible processes are SCV0-SCV9. FBDA also keeps track of how far the archiving of tracked transactions has progressed. There can be up to 36 of these processes (LMD0-LMDz). CSS monitors RDBMS instances which are connected to the Oracle ASM instance and constantly doing I/Os. The LSP1 process is spawned on a logical standby database that is intended to become the new primary database. The dispatcher slave processes enable scaling of Direct NFS connections to a clustered NAS storage. This process membership in the cluster as an I/O-capable client on behalf of the Oracle ASM volume driver. Common background server for basic messaging and RDMA primitives based on IPC (Inter-process communication) methods. The Data Pump worker process is responsible for performing tasks that are assigned by the Data Pump master process, such as the loading and unloading of metadata and data. Communicates between the Oracle ASM instance and the operating system volume driver. There can be up to 36 of these slave processes (LDD0-LDDz). The default number of these processes is based on number of CPUs. Every 30 seconds the process processes and publishes run-time load-balancing information and keeps the topology information current. This process is used for handling invalidation and other messages generated by server processes attached to other instances in Oracle RAC. On a host with multiple NUMA nodes, there will be at least one Unnn process per NUMA node. The dictionary is necessary for logical standby databases to interpret the redo of the new primary database. Performs or schedules many manageability tasks. Relays messages between Oracle ASM instance and Oracle ASM Proxy instance that is used by ADVM (for ACFS), Performs various background space management tasks, including proactive space allocation and space reclamation. Database instances, XStream Outbound Server, Sets resource plans and performs other tasks related to the Database Resource Manager. INSV is created when the DG_BROKER_START initialization parameter is set to true. Background processes are the processes r. NSSn can run as multiple processes, where n is 1-9 or A. DMON interacts with the local database and the DMON processes of the other databases to perform the requested function. 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. QMNC is the non-sharded queue master process responsible for facilitating various background activities required by AQ and Oracle Streams: time management of messages, management of nonpersistent queues, cleanup of resources, and so on. They receive and perform units of work sent from the query coordinator. I/O errors can be emulated on Oracle ASM disk I/O through named events. The default number of these processes is based on number of CPUs. Possible processes are ARC0-ARC9 and ARCa-ARCt. Performs a logical standby dictionary build on a primary database. The Oracle RAC processes and their identifiers are as follows: 1. LMS, where n is 0-9 or a-z, maintains a lock database for Global Cache Service (GCS) and buffer cache resources. Apply servers can also enqueue a queue. PMAN monitors, spawns, and stops the following as needed. See Also: Oracle Database XStream 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. The I/O slaves simulate the asynchronous I/O behavior when the underlying platform does not have native support for asynchronous I/O. The slave can repeat this operation in case additional jobs need to be run. FSFP is created when fast-start failover is enabled. Upgrade Oracle Database from 11.2.0.4 to 12.2.0.1 (Exadata RAC on Premise) Historical SQL Monitor reports in 12c! SCCn acts as a slave process for SCRB and performs the checking operations. FBDA maintains metadata on the current rows and tracks how much data has been archived. 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. Then, the number of worker processes is computed as follows: When parallel_level is 1, no worker processes are spawned. Selects jobs that need to be run from the data dictionary and spawns job queue slave processes (Jnnn) to run the jobs. This process is used for handling invalidation and other messages generated by server processes attached to other instances in Oracle RAC. The propagation sender process name is CXnn, where nn can include letters and numbers. RMSn performs a variety of tasks, including creating resources related to Oracle RAC when new instances are added to a cluster. See Also: Oracle Database Backup and These processes run by default in a database that is open in read write mode. 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. The RMON process is spawned on demand to run the protocol for transitioning an ASM cluster in and out of rolling migration mode. Determines which database objects will be protected by the database guard. PMON periodically scans all processes to find any that have died abnormally. Coordinates execution of tasks such as filtering duplicate block media recovery requests and performing flood control. LGWR workers are not used when there is a SYNC standby destination. Mandatory Background Processes Optional Background Processes Slave Processes The DBMS_STORAGE_MAP package enables you to control the mapping operations. 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. 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. Initiates background population and repopulation of in-memory enabled objects. When you start the Data Guard broker, a DMON process is created. Several initialization parameters relate to shared servers. When the THREADED_EXECUTION initialization parameter is set to TRUE on Linux and UNIX, the DBW, PMON, PSP, and VKTM background processes run as operating system processes, and the other background processes run as operating system threads. DMON also monitors the health of the broker configuration and ensures that every database has a consistent description of the configuration. NSVn is created when a Data Guard broker configuration is enabled. See Also: Oracle Database The RPOP process is responsible for re-creating and repopulating data files from snapshots files. The background processes consolidate functions that would otherwise be handled by multiple Oracle Database programs running for each user process. LMHB monitors the CKPT, DIAn, LCKn, LGnn, LGWR, LMDn, LMON, LMSn , and RMSn processes to ensure they are running normally without blocking or spinning. The coordinator process name is ASnn, where nn can include letters and numbers. Copies the redo log files to archival storage when they are full or an online redo log switch occurs. But when I run same script in background, it hang up in background, nothing output. Captures database changes from the redo log by using the infrastructure of LogMiner. GMON monitors all the disk groups mounted in an Oracle ASM instance and is responsible for maintaining consistent disk membership and status information. MARK essentially tracks which extents require resynchronization for offline disks. After being started, the slave acts as an autonomous agent. The IMCO background process can also initiate repopulation of in-memory objects. DSKM performs operations related to Exadata I/O fencing and Exadata cell failure handling. See Also: Oracle Database The pooled server process performs network communication directly on the client connection and processes requests until the client releases the server. If a resource plan is not enabled, then this process is idle. 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. Under normal operation on non-Exadata hardware and on Exadata hardware that is not utilizing ASM volumes, these processes will not be started. This process receives, processes, and sends GCS requests, block transfers, and other GCS-related messages. 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. When performing work on behalf of the Oracle Database In-Memory option, Wnnn processes execute tasks for population or repopulation of objects that are enabled for the In-Memory column store (IM columns store), and tasks that drop in-memory segments when an object is disabled for the IM columns store. Atomic Control File to Memory Service Process, Coordinates consistent updates to a control file resource with its SGA counterpart on all instances in an Oracle RAC environment. Oracle background processes are visible as separate operating system processes in Unix/Linux. Thus, the writes tend to be slower than the sequential writes performed by LGWR. ABMR and BMRn terminate after being idle for a long time. Its primary tasks are to watch for when inaccessible disks and cells become accessible again, and to initiate the ASM ONLINE operation. For Oracle Data Appliance only, in the event of an instance crash, the surviving instance will recover the dead instance's database flash cache. The process schedules managed processes in accordance with an active resource plan. Unnn processes are database container operating system processes where database backgrounds processes like SMON, CJQ0, and database foreground processes run. 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. DMON maintains profiles about all database objects in the broker configuration in a binary configuration file. Tracks changed data blocks as part of the Recovery Manager block change tracking feature. OracleprocessDB SIDOracle instanceOracle instanceSIDADEVDBSIDATESTprocess . The ONLINE operation is handled by XDWK. Wait, 92? SMON in a non-failed instance can also perform failed instance recovery for other failed RAC instance. Performs network communication in the shared server architecture. A small fraction of SGA is allocated during instance startup. The LSP1 process is spawned on a logical standby database that is intended to become the new primary database.