配置data guard物理备库(8)

Database altered. 这时又处于MOUNT状态了

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主库 备库 切换 主库死了 备库顶上去

在主库 备库执行这条命令,查询是主库还是备库

SQL> select name,database_role from v$database; 备库

NAME DATABASE_ROLE --------- ----------------

DGDEMO PHYSICAL STANDBY

SQL> select name,database_role from v$database; 主库

NAME DATABASE_ROLE --------- ----------------

DGDEMO PRIMARY

先在主库切换

SQL> alter database commit to switchover to physical standby with session shutdown;

Database altered.

SQL> shutdown immediate

ORA-01507: database not mounted ORACLE instance shut down. SQL> startup nomount; ORACLE instance started.

Total System Global Area 218103808 bytes Fixed Size 1218604 bytes Variable Size 71305172 bytes Database Buffers 142606336 bytes Redo Buffers 2973696 bytes SQL> alter database mount standby database;

Database altered.

SQL> recover managed standby database disconnect; (这命令作用是redo apply)

Media recovery complete.

在备库执行这命令切到主库

SQL> alter database commit to switchover to primary; Database altered.

SQL> shutdown immediate SQL> startup

SQL> select name,database_role from v$database;

NAME DATABASE_ROLE --------- ----------------

DGDEMO PRIMARY 这时已经变成主库了,再试建表 插入数据 SQL> create table wwwtbl(id integer,name char(10)); Table created.

SQL> insert into wwwtbl values(1,'wzb'); 1 row created. SQL> commit; Commit complete.

SQL> select * from wwwtbl;

ID NAME ---------- ---------- 1 wzb

SQL> ALTER SYSTEM ARCHIVE LOG CURRENT; 归档

System altered.

日后维护工作

1.正确的开关机顺序是：

启动的时候，先备库的listener,再启动备库,再启动主库的listener,再启动主库。 关闭的时候，

先关闭主库(shutdown immediate)，

再关闭备库(先ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL; 再shutdown immediate)。

2.备库启动方法:startup nomount==>alter database mount standby database;==>alter database recover managed standby database disconnect from session; --应用归档

启动数据库分两种情况：

一 是主、备原来都关闭状态，主备都要启动

A)先启动备库监听 B) 启动备库 [root@node2 ~]# su - oracle [oracle@node2 ~]$ lsnrctl start [oracle@node2 ~]$ sqlplus /nolog SQL> conn /as sysdba SQL> startup nomount ORACLE instance started.

SQL> alter database mount standby database;

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION; C)启动主库监听 D)启动主库 [root@node1 ~]# su - oracle [oracle@node1 ~]$ lsnrctl start [oracle@node1 ~]$ sqlplus /nolog SQL> conn / as sysdba

SQL> startup

alter system set log_archive_dest_state_2=enable; 打开向备库发送归档日志

二 如果是主库原来在正常运行状态，只要启动备库

2.1.2 如果主数据库在正常运行状态，只需要启动备库：

然后登录到主库，执行下面步骤：

SQL>alter system set log_archive_dest_state_2=enable; 注意：此步骤在机器重启后，需启动此项，否则备库无法接受日志 然后登录到备库，执行下面两步骤： 启动备库监听

登录到主机上，执行如下命令： c:\\set ORACLE_SID=orcl c:\\lsnrctl start

启动备库

c:\\sqlplus /nolog

SQL> conn /as sysdba SQL> startup nomount

SQL> alter database mount standby database;

SQL> alter database recover managed standby database disconnect from session;

至此 备库启动完毕

设置最大可用模式

--查看保护模式 (默认是MAXIMUM PERFORMANCE 最高性能)

SQL> SELECT PROTECTION_MODE, PROTECTION_LEVEL FROM V$DATABASE;

PROTECTION_MODE PROTECTION_LEVEL -------------------- --------------------

MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE 下面的例子显示了如何配置最大可用性模式： 在主库操作以下

SQL> ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=lsnode2 LGWR SYNC AFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=uqn_node2';

System altered.

SQL> ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE AVAILABILITY;

Database altered.

重新启动数据库，以使设置生效

SQL> shutdown immediate

SQL> startup

再查看，就看到改成MAXIMUM AVAILABILITY了,在主库操作完后，在备库查也自动改为MAXIMUM AVAILABILITY SQL> SELECT PROTECTION_MODE, PROTECTION_LEVEL FROM V$DATABASE;

PROTECTION_MODE PROTECTION_LEVEL -------------------- --------------------

MAXIMUM AVAILABILITY RESYNCHRONIZATION