listener.ora是伺服器端的配置oracle的檔案。

後來將listener.ora的這一行 ：(PROGRAM = extproc) 註釋掉，就行了
修改為：
SID_LIST_LISTENER =
  (SID_LIST =
  (SID_DESC =
  (SID_NAME = prod)
  (ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
# (PROGRAM = extproc)
  )
  )

LISTENER =
  (DESCRIPTION_LIST =
  (DESCRIPTION =
  (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.8)(PORT = 1522))
  (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
  )
  )

PROGRAM = extproc 外部程式呼叫，現在已經沒用了。