Oracle 9i 数据库软件安装的时候最后自动会跳出配置监听器的画面， 我们可以配置监听，然后会生成listener.ora 及

tnsnames.ora 文件， DBCA建库的时候会将相应的数据库名称写入listener.ora及tnsnames.ora中 。那么开启一般监听是是静态注册，

监听Listener.ora 一般格式是： 

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
      )
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = pce-tsg-036)(PORT = 1521))
      )
    )
  )

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = D:\oracle\ora92)
      (PROGRAM = extproc)
    )
  )

然后在DBCA建立库之后，会在 SID_LIST_LISTENER 中加入库的sid_name 及global_name . 
在监听中有数据库信息的情况下，监听开启后都会有UNKNOWN 状态的情况存在。 

tnsnames.ora 最初的一般格式为：

INST1_HTTP =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = epdvdb)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = SHARED)
      (SERVICE_NAME = MODOSE)
      (PRESENTATION = http://HRService)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

EPDV =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.164.68.78)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = epdv)
    )
  )

但是Oracle 10g 中安装数据库软件的时候不再提示配置监听器，而需要安装软件完成后，自己NETCA来建立，才能生成listener.ora

及tnsnames.ora 文件。

如果在netca之前已经通过dbca建库了，再次netca 建立的listener.ora 及tnsnames.ora 中不会有所建库的相关service name
信息， lsnrctl  start  开启后也不会有库的相关监听信息，客户端不能正常访问，会报错。 

正常情况下安装Oracle10g 软件后，Netca 建立监听信息，生成listener.ora及tnsnames.ora 文件 。
Listener.ora 格式如下 (不再包含有数据库实例名称信息，可能是由于动态注册的原因)：   

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /u01/product/oracle)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.13.67.158)(PORT = 1526))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )

正常情况下的tnsnames.ora文件如下：

MXDELL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.13.67.158)(PORT = 1526))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = mxdell)
    )
  )

LISTENER_MXDELL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = 10.13.67.158)(PORT = 1526))

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

 
同时初始话参数 local_listener 会被设置为 local_listener='LISTENER_MXDELL' 

以上正常的情况下，lsnrctl status 看到的是动态注册的信息(有时候需要等2~3分钟
才能看到)：

Listener Parameter File   /u01/product/oracle/network/admin/listener.ora
Listener Log File         /u01/product/oracle/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.13.67.158)(PORT=1526)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "mxdell" has 1 instance(s).
  Instance "mxdell", status READY, has 1 handler(s) for this service...
Service "mxdellXDB" has 1 instance(s).
  Instance "mxdell", status READY, has 1 handler(s) for this service...
Service "mxdell_XPT" has 1 instance(s).
  Instance "mxdell", status READY, has 1 handler(s) for this service...
The command completed successfully 

如果在类似9i 手工在 listener.ora 中设置了数据库实例的信息，那么lsnrctl status
出现如下信息 ， READY 及 UNKNOWN 状态都会出现。 

Service "mxdell" has 2 instance(s).
  Instance "mxdell", status UNKNOWN, has 1 handler(s) for this service...
  Instance "mxdell", status READY, has 1 handler(s) for this service...

动态注册情况下，关闭和开启数据库的时候，监听会随之关闭及开启 。