ORA-12518 TNS:监听程序无法分发客户机连接的解决办法

一、listener文件中的GLOBAL_DBNAME ,SID_NAME可能与实例名称不符，修改后，重启listener.

二、专有服务器模式下processes值设的过小。

　　可通过以下方法解决：

1.cmd

2.sqlplus

3.connect sys/test as sysdba

4.查看会话数、processes、sessions

　　

SQL> select count(*) from v$session;

         COUNT(*)

  

        ----------

           45

　　

SQL> show parameter processes

    NAME                                 TYPE        VALUE

    db_writer_processes                  integer     1

    gcs_server_processes                 integer     0

    job_queue_processes                  integer     10

    log_archive_max_processes            integer     2

    processes                            integer     50

SQL> show parameter sessions

    NAME                                 TYPE        VALUE

    java_soft_sessionspace_limit         integer     0l

    icense_max_sessions                 integer     0

    license_sessions_warning             integer     0

    logmnr_max_persistent_sessions       integer     1

    sessions                             integer     60

    shared_server_sessions               integer

　　5.修改processes和sessions值:sessions=(1.1*process+5)

  SQL> alter system set processes=300 scope=spfile;

 系统已更改。

SQL> alter system set sessions=335 scope=spfile;

   系统已更改。

　　6.重启数据库，使更改生效

　　（不过我没有重启）

三、共享模式下

1.show parameters dispatchers;

show parameters dispatchers;

NAME TYPE VALUE

dispatchers string (protocol=tcp)(service=oracle10xdb)

max_dispatchers integer

2.确定是否有足够的dispatchers

SQL> select name, (busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ;

NAME dispatcher busy rate

---- --------------------

D000 .000121704

D001 .000042597

D002 .004935402

如果超过50%，则需要考虑增加更多的dispatchers;

3.改变dispathchers:

SQL>alter system set dispatchers = '(protocol=tcp)(dispatchers=3)(service=oracle10xdb)';

system altered

四、PGA内存设置太小

注：该方法没试过。

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按照如上我的解决方案：

cmd调出命令行窗口

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator>sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on 月 2月 20 13:45:30 2012

Copyright (c) 1982, 2005, Oracle. All rights reserved.

 

SQL> connect sys/test as sysdba

Was connected to an idle instance.

 

SQL> show parameters dispatchers;

ORA-01034: ORACLE not available

 

SQL> connect SYS/SYSADMIN as sysdba

Was connected to an idle instance.

 

SQL> select count(*) from v$session;

 

SQL> show parameter processes

 

SQL> alter system set processes=1000 scope=spfile;

 

SQL> alter system set sessions=1100 scope=spfile;

 

SQL> select  name, (busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ;

　　重新登录就可以了