11g新增加的后台进程

启动阶段日志:

 

TTR advisory is disabled because FAST_START_MTTR_TARGET is notset
Wed Apr 09 00:38:31 2014
SMON: enabling cache recovery
Wed Apr 09 00:39:38 2014
minact-scn: Inst 2 is a slave inc#:40 mmon proc-id:10825status:0x2
minact-scn status: grec-scn:0x0000.00000000gmin-scn:0x0000.00000000 gcalc-scn:0x0000.00000000
Wed Apr 09 00:40:21 2014
Incremental checkpoint up to RBA [0x7.2.0], current log tail at RBA[0x7.4.0]
Wed Apr 09 00:42:51 2014
[10904] Successfully onlined Undo Tablespace 31.
Undo initialization finished serial:0 start:2098892120end:2099085865 diff:193745 (1937 seconds)
Verifying file header compatibility for 11g tablespaceencryption..
Verifying 11g file header compatibility for tablespace encryptioncompleted
Wed Apr 09 00:42:51 2014
SMON: enabling tx recovery
Database Characterset is UTF8
Wed Apr 09 00:43:19 2014
No Resource Manager plan active
Wed Apr 09 00:44:33 2014
Starting background process GTX0
Wed Apr 09 00:44:33 2014
GTX0 started with pid=40, OS id=11149
Wed Apr 09 00:44:48 2014
Starting background process RCBG
Wed Apr 09 00:44:48 2014
RCBG started with pid=41, OS id=11153
Wed Apr 09 00:45:03 2014
replication_dependency_tracking turned off (no async multimasterreplication found)
Wed Apr 09 00:48:56 2014
Starting background process QMNC
Wed Apr 09 00:48:56 2014
QMNC started with pid=39, OS id=11208
Wed Apr 09 00:59:09 2014
Completed: alter database open

 

 

参考文档：

New Background Processes In 11g (Îĵµ ID 444149.1)תµ½µ×²¿ 

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In this Document

 Purpose
 Details

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Applies to:
Oracle Database - Enterprise Edition - Version 11.1.0.6 to 11.2.0.2[Release 11.1 to 11.2]
Information in this document applies to any platform.
***Checked for relevance on 21-Oct-2010***

 

Purpose
This article provides information on new background processesintroduced in 11g.

A complete list of background processes can be found in theOracle Documentation:
http://docs.oracle.com/cd/E11882_01/server.112/e17110/bgprocesses.htm#sthref4453

 

Details
*  ACMS (atomic controlfile to memory service)per-instance process is an agent that contributes to ensuring adistributed SGA memory update is either globally committed onsuccess or globally aborted in the event of a failure in an OracleRAC environment.
 

*  DBRM (database resource manager) process isresponsible for setting resource plans and other resource managerrelated tasks.

 

 

*  DIA0 (diagnosability process 0) (only 0 iscurrently being used) is responsible for hang detection anddeadlock resolution.

 

*  DIAG (diagnosability) process performsdiagnostic dumps and executes global oradebug commands.

 

*  EMNC (event monitor coordinator) is thebackground server process used for database event management andnotifications.

 

*  FBDA (flashback data archiver process) archivesthe historical rows of tracked tables into flashback data archives.Tracked tables are tables which are enabled for flashback archive.When a transaction containing DML on a tracked table commits, thisprocess stores the pre-image of the rows into the flashbackarchive. It also keeps metadata on the current rows.

FBDA is also responsible for automatically managing theflashback data archive for space, organization, and retention andkeeps track of how far the archiving of tracked transactions hasoccurred.
 

*  GTX0-j (global transaction) processes providetransparent support for XA global transactions in an Oracle RACenvironment. The database autotunes the number of these processesbased on the workload of XA global transactions.

   Global transactionprocesses are only seen in an Oracle RAC environment.

 

*  KATE performs proxy I/O to an ASM metafile whena disk goes offline.

 

*  MARK marks ASM allocation units as stalefollowing a missed write to an offline disk.

 

*  SMCO (space management coordinator) processcoordinates the execution of various space management relatedtasks, such as proactive space allocation and space reclamation. Itdynamically spawns slave processes (Wnnn) to implement thetask.

 

 

*  VKTM (virtual keeper of time) is responsiblefor providing a wall-clock time (updated every second) andreference-time counter (updated every 20 ms and available only whenrunning at elevated priority).

Some additional Processes not documented in 10G :

 

* PZ (PQ slaves used for global Views) are RAC Parallel ServerSlave processes, but they are not normal parallel slave processes,PZnn processes (starting at 99) are used to query GV$ views whichis done using Parallel Execution on all instances, if more than onePZ process is needed, then PZ98, PZ97,... (in that order) arecreated automatically.

 

* O00 (ASM slave processes) A group of slave processes establishconnections to the ASM instance. Through this connection pooldatabase processes can send messages to the ASM instance. Forexample opening a file sends the open request to the ASM instancevia a slave. However slaves are not used for long runningoperations such as creating a file. The use slave (pool)connections eliminate the overhead of  logginginto the ASM instance for short requests
 

 * x000 - Slave used to expell disks afterdiskgroup reconfiguration