ora-125000

OracleOraHome92TNSListener服务已经启动，但是用PL/SQL登录时仍出现ora-125000错误。
ora-125000错误，该怎么解决？


------解决方法--------------------------------------------------------
Error:  ORA-12500 / TNS-12500
Text:  TNS:listener failed to start a dedicated server process
-------------------------------------------------------------------------------
Cause:  The process of starting up a dedicated server process failed.
  the executable could not be found or the environment maybe set up
  incorrectly.
Action: Turn on tracing at the ADMIN level and reexecute the operation.
  Verify that the ORACLE Server executable is present and has execute
  permissions enabled.
  Ensure that the ORACLE environment is specified correctly in
  LISTENER.ORA. If error persists, contact Worldwide Customer
  Support.
Explanation:
  When the listener receives a connect request for a dedicated
  connection it tries to spawn and execute an Oracle process to
  accept the connect request.