DG的配置，在配置的时候首先得理解redo log,archive log,standby log;primary 产生redo log

然后将其归档为archive log存放并将redo log 传输到standby 库上转变成standby log,该存放位置通过参数文件中的参数standby_archive_dest来指定。而且primary和物理standby的db_name是一样的，通过db_unquie_name来区别！！

物理DG的配置：

在Primary数据库配置

1确定主库处于归档模式：archive log list

2将primary数据库设为FORCE LOGGING模式：alter database force logging;

3创建standby数据库控制文件：alter batabse create standby controlfile  as '/tmp/standby.ctl'

创建primary数据库的pfile文件，

然后配置standby库

Startup nomount；

Alter database mount standby databae;

Alter database recover managed standby database disconnect  from session;

Alter databae recover managed standby database disconnect cancel;

在配置物理standby的时候出现的问题：

1． Standby日志文件的位置不对

Alter system set standby_file_managedment=manual;

Alter database databasename rename .. to ..

Alter system set standby_file_managedment=auot;

2.角色切换

NOT ALLOWED - Either this is a standby database and the primary database has not been

switched first, or this is a primary database and there are no standby databases.
    SESSIONS ACTIVE - Indicates that there are active SQL sessions attached to the primary or standby database that need to be disconnected before the switchover operation is permitted.

如果主库是sessions atchive， 备库是 not allowed都是正常的。主备库切换：

Primary：

Alter database commit to switchover to physical standby with session shutdown;

Shutdown immediate;

Startup mount;

Standby:

Alter database commit to switchover to primary ;

Alter database open

再查看主备库的switchover_status

然后在之前的主库上开始接收应用                                         

Alter database recover managed standby database disconnect from session

查看 主从库的switchover_status

逻辑standby配置：

配置好物理standby之后，配置逻辑standby，首先得停止物理standby的redo 应用；

在standby库上建立standby redo log,可以多创建几组:

Alter database add standby logfile group 4 (‘/oradata/redhat1/redostb1.log’) size 10m;

……

将primary开启supplementl log功能：

Alter database add supplemental log data;

Select supplemental_log_data_pk from v$database;

然后 生成logminer字典信息：execute dbms_logstadby.build;

(该过程专门用于生成记录的元数据信息到redo log传输到logical standby;才会被logical standby进行SQL应用)

转换物理standby为逻辑standby：

Alter database recover to logical standby new_dbname;(这里new_dbname为全新的dbname,和primary的不一样)

然后重建密码文件和调整standby 参数文件

打开逻辑standby：

Alter database open resetlogs;

Alter database start logical standby apply immediate;

Alter database stop logical standby apply immediate;(停止逻辑standby的SQL应用)

下面为primary和standby的参数文件：

Primary：

redhat.__db_cache_size=83886080

redhat.__java_pool_size=4194304

redhat.__large_pool_size=4194304

redhat.__shared_pool_size=71303168

redhat.__streams_pool_size=0

*.audit_file_dest='/orahome/admin/redhat/adump'

*.background_dump_dest='/orahome/admin/redhat/bdump'

*.compatible='10.2.0.1.0'

*.control_files='/oradata/redhat/control01.ctl','/oradata/redhat/control02.ctl','/oradata/redhat/control03.ctl'

*.core_dump_dest='/orahome/admin/redhat/cdump'

*.db_block_size=8192

*.db_domain=''

*.db_file_multiblock_read_count=16

*.db_name='redhat'

*.dispatchers='(PROTOCOL=TCP) (SERVICE=redhatXDB)'

*.job_queue_processes=10

*.open_cursors=300

*.pga_aggregate_target=16777216

*.processes=150

*.remote_login_passwordfile='EXCLUSIVE'

*.sga_target=167772160

*.undo_management='AUTO'

*.undo_tablespace='UNDOTBS1'

*.user_dump_dest='/orahome/admin/redhat/udump'

log_archive_format='%t_%s_%r.arc'

db_unique_name=redhat

*.log_archive_config='DG_CONFIG=(redhat,redhat1)'

*.log_archive_dest_1='location=/archive/redhat/ VALID_FOR=(ONLINE_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=redhat'

log_archive_dest_2='service=redhat1  LGWR  ASYNC  VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=redhat1'

log_archive_dest_3='location=/archive/redhat_stb/ VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=redhat'

log_archive_max_processes=2

log_archive_dest_state_1=enable

log_archive_dest_state_2=enable

log_archive_dest_state_3=enable

remote_login_passwordfile=exclusive

fal_server=redhat1

fal_client=redhat

db_file_name_convert='/oradata/redhat/','/oradata/redhat1/'

log_file_name_convert='/archive/redhat/','/archive/redhat1/','/archive/redhat_stb','/archive/redhat1_stb'

standby_file_management=AUTO

standby_archive_dest='/archive/redhat_stb'

standby：

db_cache_size=83886080

java_pool_size=4194304

shared_pool_size=71303168

streams_pool_size=0

*.audit_file_dest='/orahome/admin/redhat1/adump'

*.background_dump_dest='/orahome/admin/redhat1/bdump'

*.compatible='10.2.0.1.0'

*.control_files='/oradata/redhat1/control01.ctl'

*.core_dump_dest='/orahome/admin/redhat1/cdump'

*.db_block_size=8192

*.db_domain=''

*.db_file_multiblock_read_count=16

*.db_name='redhat'

*.dispatchers='(PROTOCOL=TCP) (SERVICE=redhatXDB)'

*.job_queue_processes=10

*.open_cursors=300

*.pga_aggregate_target=16777216

*.processes=150

*.remote_login_passwordfile='EXCLUSIVE'

*.sga_target=167772160

*.undo_management='AUTO'

*.undo_tablespace='UNDOTBS1'

*.user_dump_dest='/orahome/admin/redhat1/udump'

log_archive_format='%t_%s_%r.arc'

db_unique_name=redhat1

*.log_archive_config='DG_CONFIG=(redhat,redhat1)'

*.log_archive_dest_1='location=/archive/redhat1/ VALID_FOR=(ONLINE_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=redhat1'

log_archive_dest_2='service=redhat  LGWR  ASYNC  VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=redhat'

log_archive_dest_3='location=/archive/redhat1_stb VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=redhat1'

log_archive_dest_state_1=enable

log_archive_dest_state_2=enable

log_archive_dest_state_3=defer

remote_login_passwordfile=exclusive

fal_server=redhat

fal_client=redhat1

db_file_name_convert='/oradata/redhat/','/oradata/redhat1/'

log_file_name_convert='/archive/redhat/','/archive/redhat1/','/archiv/redhat_stb/','/archive/redhat1_stb/'

standby_file_management=AUTO

standby_archive_dest='/archive/redhat1_stb/'    ---该目录为从primary传递过来的archive log而standby自己的archive log 存放在 ‘/archive/redhat1/ 目录下 通过log_archive_dest来指定。