dataguard ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

錯誤的意思是listener 不知道鏈接解析器中的請求服務，這裏要說靜態監聽和動態監聽了
動態註冊是在instance啓動的時候PMON進程根據init.ora中的instance_name,service_names兩個參數將實例和服務動態註冊到listener中。
靜態註冊就是實例啓動時讀取listener.ora文件的配置，將實例和服務註冊到監聽程序。不管什麼時候啓動一個數據庫，默認地都有兩條信息註冊到監聽器中：數據庫服務器對應的實例和服務。
搭建dataguard過程當中，先啓動的數據庫，沒有在listener.ora 中設置靜態監聽。從新設置後。
# listener.ora Network Configuration File: /opt/oracle/10.2.0/orcl/network/admin/listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =

  (SID_LIST =

    (SID_DESC =

      (SID_NAME = orclpdg)

      (ORACLE_HOME = /opt/oracle/10.2.0/orcl)

    )

 --增長內容 BEGIN

    (SID_DESC =  

      (SID_NAME  = PLSExtProc)   

      (ORACLE_HOME = /opt/oracle/10.2.0/orcl)          

      (PROGRAM   =  extproc) 

    )   

  )

 --增長內容 END 

LISTENER =

  (DESCRIPTION_LIST =

    (DESCRIPTION =

      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))

      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.250.7.230 )(PORT = 1521))

    )

  )

oracle@yangDB2:/opt/oracle/10.2.0/orcl/network/admin>lsnrctl
LSNRCTL> status
LSNRCTL> reload
LSNRCTL> status