oracle dg 三大模式切换
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1 最大性能模式maximum performance ——默认模式
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一 最大性能模式特点
192.168.1.181
sql> select database_role,protection_mode,protection_level from v$database;
database_role protection_mode protection_level
---------------- -------------------- --------------------
primary maximum performance maximum performance
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive
name type value
------------------------------------ ----------- ------------------------------
log_archive_config string dg_config=(orcl,db01)
log_archive_dest_1 string location=/home/oracle/arch_orc
l valid_for=(all_logfiles,all_
roles) db_unique_name=orcl
log_archive_dest_2 string service=db_db01 lgwr async val
id_for=(online_logfiles,primar
y_roles) db_unique_name=db01
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 31
next log sequence to archive 33
current log sequence 33
192.168.1.183
sql> select database_role,protection_mode,protection_level from v$database;
database_role protection_mode protection_level
---------------- -------------------- --------------------
physical standby maximum performance maximum performance
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive
name type value
------------------------------------ ----------- ------------------------------
log_archive_config string dg_config=(db01,orcl)
log_archive_dest_1 string location=/home/oracle/arch_db0
1 valid_for=(all_logfiles,all_
roles) db_unique_name=db01
log_archive_dest_2 string service=db_orcl lgwr async val
id_for=(online_logfiles,primar
y_roles) db_unique_name=orcl
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 31
next log sequence to archive 33
current log sequence 33
192.168.1.181
sql> alter system switch logfile;
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 32
next log sequence to archive 34
current log sequence 34
192.168.1.183
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_db01
oldest online log sequence 32
next log sequence to archive 0
current log sequence 34
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2 最大性能模式–切换到–>最大高可用 (默认是最大性能模式—maximum performance)
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192.168.1.181
sql> select database_role,protection_mode,protection_level from v$database;
database_role protection_mode protection_level
---------------- -------------------- --------------------
primary maximum performance maximum performance
sql> show parameter log_archive_dest_2
name type value
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string service=db_db01 lgwr async val
id_for=(online_logfiles,primar
y_roles) db_unique_name=db01
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sql> shutdown immediate
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sql> alter database recover managed standby database cancel;
sql> shutdown immediate
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sql> startup mount;
sql> alter database set standby database to maximize availability;
sql> alter system set log_archive_dest_2='service=db_db01 lgwr sync valid_for=(online_logfiles,primary_roles) db_unique_name=db01' scope=spfile;
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sql> startup nomount
sql> alter database mount standby database;
sql> alter system set log_archive_dest_2='service=db_orcl lgwr sync valid_for=(online_logfiles,primary_roles) db_unique_name=orcl' scope=spfile;
sql> shutdown immediate
sql> startup nomount
sql> alter database mount standby database;
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sql> startup
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive_dest_2
name type value
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string service=db_db01 lgwr sync vali
d_for=(online_logfiles,primary
_roles) db_unique_name=db01
sql> select database_role,protection_level,protection_mode from v$database;
database_role protection_level protection_mode
---------------- -------------------- --------------------
primary maximum availability maximum availability
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 34
next log sequence to archive 36
current log sequence 36
192.168.1.183
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive_dest_2
name type value
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string service=db_orcl lgwr sync vali
d_for=(online_logfiles,primary
_roles) db_unique_name=orcl
sql> select database_role,protection_level,protection_mode from v$database;
database_role protection_level protection_mode
---------------- -------------------- --------------------
physical standby maximum availability maximum availability
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_db01
oldest online log sequence 35
next log sequence to archive 0
current log sequence 36
192.168.1.181
sql> alter system switch logfile;
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 35
next log sequence to archive 37
current log sequence 37
192.168.1.183
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_db01
oldest online log sequence 36
next log sequence to archive 0
current log sequence 37
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3 最大高可用–切换到–>最保护能模式
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dg最大保护模式maximum protection
192.168.1.181
sql> shutdown immediate
192.168.1.183
sql> shutdown immediate
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sql> alter database set standby database to maximize protection;
sql> shutdown immediate
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sql> startup nomount
sql> alter database mount standby database;
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sql> startup
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive_dest_2
name type value
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string service=db_db01 lgwr sync vali
d_for=(online_logfiles,primary
_roles) db_unique_name=db01
sql> select database_role,protection_level,protection_mode from v$database;
database_role protection_level protection_mode
---------------- -------------------- --------------------
primary maximum protection maximum protection
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 37
next log sequence to archive 39
current log sequence 39
192.168.1.183
sql> col dest_name for a25
sql> select dest_name,status from v$archive_dest_status;
dest_name status
------------------------- ---------
log_archive_dest_1 valid
log_archive_dest_2 valid
sql> show parameter log_archive_dest_2
name type value
------------------------------------ ----------- ------------------------------
log_archive_dest_2 string service=db_db01 lgwr sync vali
d_for=(online_logfiles,primary
_roles) db_unique_name=db01
sql> select database_role,protection_level,protection_mode from v$database;
database_role protection_level protection_mode
---------------- -------------------- --------------------
primary maximum protection maximum protection
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_db01
oldest online log sequence 37
next log sequence to archive 0
current log sequence 39
192.168.1.181
sql> alter system switch logfile;
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_orcl
oldest online log sequence 38
next log sequence to archive 40
current log sequence 40
192.168.1.183
sql> archive log list
database log mode archive mode
automatic archival enabled
archive destination /home/oracle/arch_db01
oldest online log sequence 37
next log sequence to archive 0
current log sequence 40
附：oracle dg管理模式和只读模式相互切换
将standby数据库开启至只读模式(用于primary非常忙时，可以在standby跑一些报表)
$sqlplus “/as sysdba” sql>startup mount sql>alter database open read only; [@more@]
将只读模式standby数据库切换至管理模式
$sqlplus “/as sysdba” sql>alter database recover managed standby database disconnect from session;
将管理模式的standby数据库切换至只读模式
$sqlplus “/as sysdba” sql>alter database recover managed standby database cancel; sql>alter database open read only;
以上内容给大家介绍了oracle dg 三种模式切换的相关知识，希望大家喜欢。