准备：
    确认对象和语句能被standby支持
    确保primary库中各表的行可被唯一标识
    环境：
    操作系统：RED HAT LINUX ENTERPRISE 5
    ORACLE:   11.2.0.1.0
    PRIMARY:
    IP:    192.168.1.11
    SID:  test
    DB_UNIQUE_NAME:test
    安装路径：/oracle/oracle/product/11.2.0/dbhome_1
    本地归档路径：/oracle/oradata/test/archive
    PHYSICS STANDBY：
    IP:    192.168.1.12
    SID:  dgtest
    DB_UNIQUE_NAME:dgtest
    安装路径：/oracle/oracle/product/11.2.0/dbhome_1
    本地归档路径：/oracle/oradata/dgtest/dgtest/archive
    LOGICAL STANDBY:
    IP:    192.168.1.15
    SID:  logicdg
    DB_UNIQUE_NAME: logicdg
    安装路径：/oracle/oracle/product/11.2.0/dbhome_1
    本地归档路径：/oracle/oradata/logicdg/local-archive
    本例测试采用物理standby转逻辑standby的方式在一个已经存在的dataguard环境中新增一台逻辑standby.
    原dataguard环境可参考：
    http://xin23.blog.51cto.com/1827266/504066
    创建新物理standby的过程亦可参照此文。此处不再赘述。
    则目前环境为：
    primary：192.168.1.11
    physics： 192.168.1.12
    logical：  192.168.1.15 （目前为物理standby.待转换）
    1.修改primary初始化参数文件（仅列出修改部分）
    *.log_archive_dest_state_2=defer
    *.log_archive_dest_state_3=defer
    *.log_archive_config='dg_config=（test,dgtest,logicdg）'
    *.log_archive_dest_2='service=test12 arch valid_for=（online_logfiles,primary_role） db_unique_name=dgtest'
    *.log_archive_dest_3='service=test15 arch valid_for=（online_logfiles,primary_role） db_unique_name=logicdg'
    *.fal_server=test11
    *.fal_client=test12
    *.standby_file_management=auto
    *.db_file_name_convert='/oracle/oradata/test','/oracle/oradata/dgtest/dgtest','/oracle/oradata/test','/

oracle/oradata/logicdg'
    *.log_file_name_convert='/oracle/oradata/test','/oracle/oradata/dgtest/dgtest','/oracle/oradata/test','/

oracle/oradata/logicdg'

    2.查看两台物理standby同步状态
    physics> select sequence#,applied from v$archived_log;
    SEQUENCE# APPLIED
    ---------- ---------
    66 YES
    67 YES
    68 YES
    69 YES
    70 YES
    71 YES
    72 YES
    7 rows selected.
    -----------------------------------------------------------------------------
    logical> select sequence#,applied from v$archived_log;
    SEQUENCE# APPLIED
    ---------- ---------
    67 YES
    68 YES
    69 YES
    70 YES
    71 YES
    72 YES
    6 rows selected.
    3.取消待转换物理standby的redo应用
    logical> alter database recover managed standby database cancel;
    Database altered.
    4.primary生成数据字典
    primary> execute dbms_logstdby.build;
    PL/SQL procedure successfully completed.
    5.将物理standby转换为逻辑standby
    logical> alter database recover to logical standby logicdg;
    Database altered.
    logical> shutdown immediate
    ORA-01507: database not mounted
    ORACLE instance shut down.
    logical> startup mount
    ORACLE instance started.
    Total System Global Area 2488635392 bytes
    Fixed Size                  2215904 bytes
    Variable Size            1392508960 bytes
    Database Buffers         1090519040 bytes
    Redo Buffers                3391488 bytes
    Database mounted.
    6.调整standby初始化参数
    logical> alter system set log_archive_dest_1='location=/oracle/oradata/logicdg/local-archive valid_for=（online_logfiles,all_roles）
    2  db_unique_name=logicdg';
    System altered.
    logical> alter system set log_archive_dest_5='location=/oracle/oradata/logicdg/archive valid_for=（standby_logfiles,standby_role）
    2  db_unique_name=logicdg';
    System altered.
    7.resetlogs方式打开数据库
    logical> alter database open resetlogs;
    Database altered.
    8.应用redo
    创建standby redologs
    logical> alter database add standby logfile group 11 '/oracle/oradata/logicdg/standbyredo11.log' size 100m;
    Database altered.
    logical> alter database add standby logfile group 12 '/oracle/oradata/logicdg/standbyredo12.log' size 100m;
    Database altered.
    logical> alter database add standby logfile group 13 '/oracle/oradata/logicdg/standbyredo13.log' size 100m;
    Database altered.
    启动redo实时应用
    logical> alter database start logical standby apply immediate;
    Database altered.