这篇文章描述为RAC环境创建STANDBY数据库。
由于篇幅限制，加上碰到了很多的bug，只能将文章拆分成多篇。
这章介绍STANDBY数据库创建的后续操作，并检查STANDBY运行机制：
首先登陆实例，检查数据库状态：
bash-3.00$ sqlplus "/ as sysdba"
SQL*Plus: Release 11.1.0.6.0 - Production on Wed Sep 10 13:56:13 2008
Copyright (c) 1982, 2007, Oracle. All rights reserved.
Connected to:
Oracle Database11gEnterprise Edition Release 11.1.0.6.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
rac11g1 MOUNTED
SQL> select name,
2 open_mode,
3 database_role,
4 guard_status,
5 db_unique_name,
6 primary_db_unique_name
7 from v$database;
NAME OPEN_MODE DATABASE_ROLE GUARD_S DB_UNIQUE_NAME PRIMARY_DB_UNIQUE_NAME
--------- ---------- ---------------- ------- --------------- -----------------------
RAC11G MOUNTED PHYSICAL STANDBY NONE rac11g_s
下面可以将数据库至于应用归档的状态：
SQL> alter database recover managed standby database
2 disconnect from session;
Database altered.
下面检查归档的是否可以正常发送到STANDBY数据库：
SQL> select sequence#, thread# from v$archived_log order by first_time;
no rows selected
SQL> conn sys/test@rac11gas sysdba
Connected.
SQL> alter system archive log current;
System altered.
SQL> conn / as sysdba
Connected.
SQL> select sequence#, thread# from v$archived_log order by first_time;
SEQUENCE# THREAD#
---------- ----------
533 1
198 2
SQL> select sequence#, thread#, applied from v$archived_log order by first_time;
SEQUENCE# THREAD# APP
---------- ---------- ---
532 1 YES
533 1 NO
198 2 YES
可以看到，两个数据库实例的归档日志文件已经发送到本地节点，而且LGWR进程已经将正在写的当前日志文件533写到了本地。
数据库的STANTDBY机制已经正常运行，下面看看能否将STANDBY数据库的两个实例以只读方式打开：
SQL> alter database recover managed standby database cancel;
Database altered.
SQL> alter database open;
Database altered.
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
rac11g1 OPEN
SQL> select name,
2 open_mode,
3 database_role,
4 guard_status,
5 db_unique_name,
6 primary_db_unique_name
7 from v$database;
NAME OPEN_MODE DATABASE_ROLE GUARD_S DB_UNIQUE_NAME PRIMARY_DB_UNIQUE_NAME
--------- ---------- ---------------- ------- --------------- -----------------------
RAC11G READ ONLY PHYSICAL STANDBY NONE rac11g_s rac11g
由于SPFILE目前在本地，需要创建一个ASM上面的参数文件：
SQL> create pfile='/export/home/oracle/initrac11g.ora' from spfile;
File created.
SQL> create spfile='+DATA/RAC11G/spfilerac11g.ora'
2 from pfile='/export/home/oracle/initrac11g.ora';
File created.
下面分别编辑两个节点的$ORACLE_HOME/dbs目录下的初始化参数，使得spfile指向这个刚刚创建的spfile文件：
spfile=+DATA/RAC11G/spfilerac11g.ora
下面登陆节点二，尝试打开第二个实例：
$ sqlplus "/ as sysdba"
SQL*Plus: Release 11.1.0.6.0 - Production on星期三9月10 14:53:09 2008
Copyright (c) 1982, 2007, Oracle. All rights reserved.
已连接到空闲例程。
SQL> startup
ORACLE例程已经启动。
Total System Global Area 1.7108E+10 bytes
Fixed Size 2101632 bytes
Variable Size 3478638208 bytes
Database Buffers 1.3623E+10 bytes
Redo Buffers 4431872 bytes
数据库装载完毕。
数据库已经打开。
SQL> set pages 100 lines 120
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
---------------- ------------
rac11g2 OPEN
SQL> select instance_name, status from gv$instance;
INSTANCE_NAME STATUS
---------------- ------------
rac11g2 OPEN
rac11g1 OPEN
SQL> select name,
2 open_mode,
3 database_role,
4 guard_status,
5 db_unique_name,
6 primary_db_unique_name
7 from v$database;
NAME OPEN_MODE DATABASE_ROLE GUARD_S DB_UNIQUE_NAME PRIMARY_DB_UNIQUE_NAME
--------- ---------- ---------------- ------- --------------- ----------------------
RAC11G READ ONLY PHYSICAL STANDBY NONE rac11g_s rac11g
从10g以后，不需要指定MOUNT STANDBY数据库，也不需要指定OPEN READ ONLY，Oracle自动会装载STANDBY数据库，并将实例以READ ONLY方式进行打开。
下面设置一下TEMP表空间：
SQL> alter database tempfile '+DATA/RAC11G/rac11g_temp_1_4g' drop;
Database altered.
SQL> alter tablespace temp add tempfile '+DATA/RAC11G/rac11g_temp_1_4g' size4096m;
Tablespace altered.
至此RAC环境的STANDBY已经成功建立。从下一篇开始，介绍在STANDBY数据库创建过程中碰到的各种问题和解决方法。
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