详解Oracle dg 三种模式切换

发布时间：2020-12-12 17:02:27 所属栏目：百科来源：网络整理

导读：oracle dg 三大模式切换 =================================== 1 最大性能模式MAXIMUM PERFORMANCE ------默认模式 =================================== 一最大性能模式特点 select database_role,protection_mode,protection_level from v$database;DATAB

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

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_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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select DATABASE_ROLE,PROTECTION_MODE,PROTECTION_LEVEL from v$database; DATABASE_ROLE PROTECTION_MODE PROTECTION_LEVEL ---------------- -------------------- -------------------- PRIMARY MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE SQL> show parameter log_archive_dest_2 NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_dest_2 string service=db_db01 LGWR ASYNC val id_for=(online_logfiles,primar y_roles) db_unique_name=db01 192.168.1.181 SQL> shutdown immediate 192.168.1.183 SQL> alter database recover managed standby database cancel; SQL> shutdown immediate 192.168.1.181 SQL> startup mount; SQL> alter database set standby database to maximize availability; SQL> alter system set log_archive_dest_2='service=db_db01 LGWR SYNC valid_for=(online_logfiles,primary_roles) db_unique_name=db01' scope=spfile; 192.168.1.183 SQL> startup nomount SQL> alter database mount standby database; SQL> alter system set log_archive_dest_2='service=db_orcl LGWR SYNC valid_for=(online_logfiles,primary_roles) db_unique_name=orcl' scope=spfile; SQL> shutdown immediate SQL> startup nomount SQL> alter database mount standby database; 192.168.1.181 SQL> startup SQL> col dest_name for a25 SQL> select dest_name,status from v$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_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

shutdown immediate 192.168.1.183 SQL> shutdown immediate 192.168.1.181 SQL> alter database set standby database to maximize protection; SQL> shutdown immediate 192.168.1.183 SQL> startup nomount SQL> alter database mount standby database; 192.168.1.181 SQL> startup SQL> col dest_name for a25 SQL> select dest_name,protection_mode from v$database; DATABASE_ROLE PROTECTION_LEVEL PROTECTION_MODE ---------------- -------------------- -------------------- PRIMARY MAXIMUM PROTECTION MAXIMUM PROTECTION SQL> archive log list Database log mode Archive Mode Automatic archival Enabled Archive destination /home/oracle/arch_orcl Oldest online log sequence 37 Next log sequence to archive 39 Current log sequence 39 192.168.1.183 SQL> col dest_name for a25 SQL> select dest_name,protection_mode from v$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

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)

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

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

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。

（编辑：李大同）