我配置了一套dataguard，一主一备，数据从主到备测试通过，我想把主备切换，
在主库上面已经执行完alter database commit to switchover to physical standby with session shutdown;
后来主备没有切换成功，我想在重新测试一遍。
这时候我发现原来的主库始终处于STANDBY状态。
我把主机shutdown immediate，然后startup,
然后执行 insert into t1(f1) values (1);
提示我ORA-16000: database open for read-only access
我执行start mount;
alter database open read write;
提示我：ORA-16003: standby database is restricted to read-only access
后来我改了init.ora,把后加的有关STANDBY去掉，问题依旧
我的init如下
orcl.__db_cache_size=788529152
orcl.__java_pool_size=16777216
orcl.__large_pool_size=4194304
orcl.__oracle_base='/data/ora11/oracle'#ORACLE_BASE set from environment
orcl.__pga_aggregate_target=1048576000
orcl.__sga_target=1073741824
orcl.__shared_io_pool_size=0
orcl.__shared_pool_size=255852544
orcl.__streams_pool_size=0
*.audit_file_dest='/data/ora11/oracle/admin/orcl/adump'
*.audit_trail='db'
*.compatible='11.1.0.0.0'
*.control_files='/data/ora11/oracle/oradata/orcl/control01.ctl','/data/ora11/oracle/oradata/orcl/control02.ctl','/data/ora11/oracle/oradata/orcl/control03.ctl'
*.db_block_size=8192
*.db_domain=''
*.db_name='orcl'
*.db_recovery_file_dest='/data/ora11/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.diagnostic_dest='/data/ora11/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclXDB)'
*.open_cursors=300
*.pga_aggregate_target=1048576000
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=1073741824
*.undo_tablespace='UNDOTBS1'
------解决方案--------------------
先确认，有无权限
再一个一个的测试
你一次性开启这般多，不利于发现错误。