oracle12c cc 功能,Oracle Database12c新特性:新增加的后台进程

进程名

全名

简要描述

详细描述

组件范畴

AQPC

AQ Process Coordinator

Per instance AQ global coordinator

AQPC is responsible for performing administrative tasks for AQ Master Class Processes including commands like starting, stopping, and other administrative tasks. This process is automatically started on instance startup.

Database instances Advanced Queueing

ARSn

ASM Recovery Slave Process(进程范围 ARS0-ARS9)

Recovers ASM transactional operations

The ASM RBAL background process coordinates and spawns one or more of these slave processes to recover aborted ASM transactional operations. These processes run only in the Oracle ASM instance.

Oracle ASM instances

BWnn

Database Writer Process

Writes modified blocks from the database buffer cache to the data files

See the Long Description for the DBWn process in this table for more information about the BWnn process.

Database instances

FENC

Fence Monitor Process

Processes fence requests for RDBMS instances which are using Oracle ASM instances

CSS monitors RDBMS instances which are connected to the Oracle ASM instance and constantly doing I/Os. When the RDBMS instance terminates due to a failure, all the outstanding I/O's from the RDBMS instance should be drained and any new I/O's rejected. FENC receives and processes the fence request from CSSD.

Oracle ASM instances

GCRn

Global Conflict Resolution Slave Process

Performs synchronous tasks on behalf of LMHB

GCRn processes are transient slaves that are started and stopped as required by LMHB to perform synchronous or resource intensive tasks.

Database instances, Oracle ASM instances, Oracle RAC

IPC0

IPC Service Background Process

Common background server for basic messaging and RDMA primitives based on IPC (Inter-process communication) methods.

IPC0 handles very high rates of incoming connect requests, as well as, completing reconfigurations to support basic messaging and RDMA primitives over several transports such as UDP, RDS, InfiniBand and RC.

Oracle RAC

LDDn

Global Enqueue Service Daemon Helper Slave

Helps the LMDn processes with various tasks

LDDn processes are slave processes spawned on demand by LMDn processes. They are spawned to help the dedicated LMDn processes with various tasks when certain workloads start creating performance bottlenecks. These slave processes are transient as they are started on demand and they can be shutdown when no longer needed. There can be up to 36 of these slave processes (LDD0-LDDz).

Database instances, Oracle ASM instances, Oracle RAC

LGnn

Log Writer Worker

Writes redo log

On multiprocessor systems, LGWR creates worker processes to improve the performance of writing to the redo log. LGWR workers are not used when there is a SYNC standby destination. Possible processes include LG00-LG99.

Database instances

LREG

Listener Registration Process

Registers the instance with the listeners

LREG notifies the listeners about instances, services, handlers, and endpoint.

Database instances, Oracle ASM instances, Oracle RAC

OFSD

Oracle File Server Background Process

Serves file system requests submitted to an Oracle instance

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.

Database instances, Oracle RAC

QMnn

AQ Master Class Process

Per instance per AQ Master Class Process

Each of this type of process represents a single class of work item such as AQ notification, queue monitors, and cross process.

Database instances Advanced Queueing

RM

RAT Masking Slave Process

Extracts and masks bind values from workloads like SQL tuning sets and DB Replay capture files

This background process is used with Data Masking and Real Application Testing.

Database instances

RMON

Rolling Migration Monitor Process

Manages the rolling migration procedure for an Oracle ASM cluster

The RMON process is spawned on demand to run the protocol for transitioning an ASM cluster in and out of rolling migration mode.

Oracle ASM instance, Oracle RAC

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.

Database instances

SAnn

SGA Allocator

(SA00 ~ SAzz)

Allocates SGA

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.

Database instances

SCCn

ASM Disk Scrubbing Slave Check Process

Performs Oracle ASM disk scrubbing check operation

SCCn acts as a slave process for SCRB and performs the checking operations. The possible processes are SCC0-SCC9.

Oracle ASM instances

SCRB

ASM Disk Scrubbing Master Process

Coordinates Oracle ASM disk scrubbing operations

SCRB runs in an Oracle ASM instance and coordinates Oracle ASM disk scrubbing operations.

Oracle ASM instances

SCRn

ASM Disk Scrubbing Slave Repair Process

Performs Oracle ASM disk scrubbing repair operation

SCRn acts as a slave process for SCRB and performs the repairing operations. The possible processes are SCR0-SCR9.

Oracle ASM instances

SCVn

ASM Disk Scrubbing Slave Verify Process

Performs Oracle ASM disk scrubbing verify operation

SCVn acts as a slave process for SCRB and performs the verifying operations. The possible processes are SCV0-SCV9.

Oracle ASM instances

TTnn

Redo Transport Slave Process

Ships redo from current online and standby redo logs to remote standby destinations configured for ASYNC transport

TTnn can run as multiple processes, where nn is 00 to ZZ.

Database instances, Data Guard

VUBG

Volume drive Umbilicus Background

Relays messages between Oracle ASM instance and Oracle ASM Proxy instance that is used by ADVM (for ACFS)

Oracle ASM instances, Oracle ASM Proxy instances