Oracle体系结构及备份（十七）——bg-others

一 其他进程

Archiver (ARCn)

Oneor more archiver processes copy the redo log files to archival storage whenthey are full or a log switch occurs.

Recoverer (RECO)

The recoverer process is used to resolvedistributed transactions that are pending because of a network or systemfailure in a distributed database. At timed intervals, the local RECO attemptsto connect to remote databases and automatically complete the commit or rollbackof the local portion of any pending distributed transactions.

Dispatcher (Dnnn)

Dispatchers are optional backgroundprocesses, present only when the shared server configuration is used.

Global Cache Service (LMS)

In an Oracle Real Application Clustersenvironment, this process manages resources and provides inter-instanceresource control.

二 操作示例

[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep arc
[oracle@localhost 桌面]$ sqlplus / as sysdba;

SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jun 6 11:21:32 2013

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> select log_mode from v$database;

LOG_MODE
------------
NOARCHIVELOG

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.

Total System Global Area  838860800 bytes
Fixed Size		    1222192 bytes
Variable Size		  788531664 bytes
Database Buffers	   46137344 bytes
Redo Buffers		    2969600 bytes
Database mounted.
SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> select log_mode from v$database;

LOG_MODE
------------
ARCHIVELOG

SQL> exit;
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep arc
oracle    6644     1  0 11:22 ?        00:00:00 ora_arc0_orcl
oracle    6646     1  0 11:22 ?        00:00:00 ora_arc1_orcl
oracle    6648     1  0 11:22 ?        00:00:00 ora_arc2_orcl

SQL> show parameter log_archive_

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
log_archive_config		     string
log_archive_dest		     string
log_archive_dest_1		     string
log_archive_dest_10		     string
log_archive_dest_2		     string
log_archive_dest_3		     string
log_archive_dest_4		     string
log_archive_dest_5		     string
log_archive_dest_6		     string
log_archive_dest_7		     string
log_archive_dest_8		     string

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_9		     string
log_archive_dest_state_1	     string	 enable
log_archive_dest_state_10	     string	 enable
log_archive_dest_state_2	     string	 enable
log_archive_dest_state_3	     string	 enable
log_archive_dest_state_4	     string	 enable
log_archive_dest_state_5	     string	 enable
log_archive_dest_state_6	     string	 enable
log_archive_dest_state_7	     string	 enable
log_archive_dest_state_8	     string	 enable
log_archive_dest_state_9	     string	 enable

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
log_archive_duplex_dest 	     string
log_archive_format		     string	 %t_%s_%r.dbf
log_archive_local_first 	     boolean	 TRUE
log_archive_max_processes	     integer	 2
log_archive_min_succeed_dest	     integer	 1
log_archive_start		     boolean	 FALSE
log_archive_trace		     integer	 0

SQL> alter system set log_archive_max_processes = 2;

System altered.

SQL> exit;
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@localhost 桌面]$ ps -ef | grep ora_ | grep arc
oracle    6644     1  0 11:22 ?        00:00:00 ora_arc0_orcl
oracle    6646     1  0 11:22 ?        00:00:00 ora_arc1_orcl
oracle    6648     1  0 11:22 ?        00:00:00 ora_arc2_orcl
[oracle@localhost 桌面]$ sqlplus / as sysdba;

SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jun 6 11:24:42 2013

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> alter system switch logfile;

System altered.

SQL> exit;
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@localhost 桌面]$ sqlplus / as sysdba;

SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jun 6 11:24:59 2013

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> alter system set log_archive_max_processes=32;
alter system set log_archive_max_processes=32
*
ERROR at line 1:
ORA-00068: invalid value 32 for parameter log_archive_max_processes, must be
between 1 and 30

SQL> alter system set log_archive_max_processes=30;

System altered.

SQL> alter system set log_archive_max_processes=2;

System altered.

三 总结

1.其他进程包括ARCn、RECO、Dnnn、LMS；

2.归档进程在归档模式下有效；

3.可以动态调整归档进程的大小，但不能超过30。

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